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WOODWORKING

Joinery Tips & Techniques

From Dados to Dovetails — It’s All Here! From the lowly butt joint to the vaunted dovetail, joinery makes a woodworking project stronger, attractive and durable. Learn how to make the most common woodworking joints using hand tools and power tools, with tips to speed and improve your work. Also included are plans for jigs to make your work easier and more precise, advice on building frame-and-panel doors and step-by-step instructions for lots of dovetails, including sliding dovetails. If you’re just starting out in woodworking, or if you’re looking for a way to just improve, we’ve got the joint for you!

Joinery Tips & Techniques

HOW TO CUT PERFECT WOOD JOINTS EVERY TIME

HOW TO CUT PERFECT WOOD JOINTS EVERY TIME

US $21.99 V7982

(CAN $22.99)

ISBN-13: 978-1-4403-2348-5 ISBN-10: 1-4403-2348-8

35313 65592

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POPULAR WOOD WORKING BOOKS

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JOINERY TIPS & TECHNIQUES HOW TO CUT PERFECT WOOD JOINTS EVERY TIME FROM THE EDITORS OF POPULAR WOODWORKING

POPULAR WOODWORKING BOOKS CINCINNATI, OHIO

www.popularwoodworking.com

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Table of Contents

4

Introduction

6

Basic Joinery

CHAPTER 1

CHAPTER 2

13

Advanced Joinery CHAPTER 3

20

Router Joinery CHAPTER 4

26

Case Joinery CHAPTER 5

34

10 Tips for Tight Joints CHAPTER 6

40

4 Joints for Box Making CHAPTER 7

49

Adding Accuracy

52

Mastering Through Mortise

57

Mortise & Tenon Basics

CHAPTER 8

CHAPTER 9

CHAPTER 10

64

Router-made Mortise & Tenon CHAPTER 11

68

Template Mortising CHAPTER 12

72

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Frame Miter Joints

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CHAPTER 13

76

Compound Miters for Dummies

CHAPTER 28

134

CHAPTER 14

80

The Case for Case Miters

CHAPTER 29

137

CHAPTER 15

84

Final Word on Dovetails Half-blind Dovetails by Jig

143

Impossitails

147

Power-assisted Dovetails

150

Shouldered Sliding Dovetails

155

Sliding Dovetails

158

Variable Spaced Dovetails

164

Micro-adjustable Finger Joint Jig Super Simple Dado and Rabbet Jig The Joint Maker

175

Table Saw Tenon Jig

178

Dovetail Jig

182

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Shop-made Mortise Jig

Four Good Ways to Cut Rabbets CHAPTER 41

185

CHAPTER 27

132

Loose-tenon Joints CHAPTER 40

CHAPTER 26

129

Lock Joints CHAPTER 39

CHAPTER 25

126

Mitered Half-lap CHAPTER 38

CHAPTER 24

119

Make Accurate Half-lap Joints CHAPTER 37

173

CHAPTER 23

116

Ultrafast Frame & Panel CHAPTER 36

169

CHAPTER 22

113

Face Frame Face-Off CHAPTER 35

CHAPTER 21

109

Living on the Edge CHAPTER 34

CHAPTER 20

105

Dado Joints CHAPTER 33

CHAPTER 19

102

Cope & Stick CHAPTER 32

CHAPTER 18

97

Box Joints CHAPTER 31

CHAPTER 17

95

Biscuit Joinery Basics CHAPTER 30

CHAPTER 16

91

Mortising Jig for A Router

Right Time for Splines CHAPTER 42

188

Tongue and Groove

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Introduction

Joinery — It’s just like it sounds ... how things are joined together. When it’s applied to furniture, joinery relates to how the pieces go together. But not just how they fit together, because joinery can also refer to how they stay together. Certain woodworking joints offer different levels of strenth to the joint, and depending on what you’re building (drawers, perhaps) strength can be an important consideration in your choice of joinery. This book is filled with a variety of woodworking joints, many overlapping and expanding on one another. The most fundamental joints are covered, as well as some unusual and esoteric joints. The information is collected from multiple authors, and you’ll find that not every woodworker makes a joint exactly the same way. One of the classic disucssions is about the dovetail joint, and whether to cut the pins, or tails first. The discussion can be quite lively, and we’ve simply allowed the authors to make their point and let you decide what plan fits your project best. Along with the “how-to” information on joinery, we’ve included a number of jigs that will make your joinery work easier and more accurate. Not everyone wants or needs a jig, but again we’re sharing the information and letting you make the final decision. We hope you find the information informative and educational, and that you enjoy a little bit of entertainment along the way. — DAVID THIEL, EDITOR

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CHAPTER • 1

Basic Joinery BY NICK ENGLER

There are three basic saw cuts: crosscuts, rips and miters. Crosscuts are made perpendicular to the wood grain, rips are cut parallel to the grain and miters are made at angles diagonally across the grain. None of these requires elaborate jigs or complex techniques, but they are the building blocks to basic joinery on the table saw. Rips and crosscuts are used to form many joints, including the basic edge and butt joints, which can be used to glue up a tabletop or door frame. These two cuts are also used to cut rabbets, grooves and dados. And a variation of these cuts will create a miter joint.

Miters Miters can be the most frustrating cuts to make. Angled cuts are harder to measure and lay out than crosscuts. To make a mitered frame perfect, both the inside and outside dimension of the piece must match on each component. You should start with accurate measuring tools and some basic math, and then you will need to test and retest your setup to ensure its precision. When you make a miter cut on a table saw, you run into a problem associated with crosscuts – the factory-supplied miter gauge is too small to offer adequate support for guiding most boards. To properly support the work, you must fit the gauge with an extension fence or replace it with a sliding table. Even when using an adequately sized miter gauge, boards are inclined to creep during a miter cut because of the rotation of the blade into the cut. One way 6

PRO TIP:

Picture-perfect Miters To make sure your miters are perfect, start with a new zero-clearance throat insert on your table saw. Bring the blade up through the insert until the blade height is about 1 ⁄4" above the height of your frame material. Turn off the saw. After the blade has stopped, use a straightedge to make a mark, extending the line of the blade slot the full length of the insert. This will let you see exactly where the blade will cut. Add a sacrificial fence to your miter gauge that extends past the blade to eliminate tear-out. You can also extend the cut line to the sacrificial fence for extra alignment accuracy.

to compensate for this is to add a stop to your miter gauge fence as shown above. Your stop will also help you make repeatable, accurate miter cuts every time. Accurate angles are another problem on table saws. The stock miter gauge and blade-tilt scale on most table saws – even the best ones – are notoriously

imprecise. And you can’t use a drafting triangle to set every possible angle you might want to cut. You must use the scales to estimate the degree setting, then thoroughly test the setup until you have it right. Once the miter gauge angle is properly set, make the miter cuts. If the boards are to be joined by miter joints

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TIPS & TRICKS Illustration by Mary Jane Favorite

GREAT TIP:

Work creeps downhill as it’s cut

A simple stop clamped to your miter fence will keep your piece from slipping during the cut.

To create accurate, matching miters (or butt joints) for frame work, flip the work piece endfor-end keeping the same long edge against your miter gauge, as shown here.

Setting Between the Lines

Clamp stop here to prevent creep

Use an angle divider to help set oddball miter angles that you can’t measure with a set of drafting triangles or a square. This device, which is available from most woodworking suppliers, looks like an adjustable metal parallelogram.

Keep same face against table Blade tilted

PRO TIP:

Rotate board end for end

Right Height, Every Time

Flip board end for end

Keep same edge against miter gauge

(such as the members of a frame), you must make mirror-image miters. Note: A single miter joint is comprised of one left miter and one right miter. To do this, flip each board end-for-end, keeping the same edge against the gauge as you cut the ends. Only in rare instances when you can’t flip the board should you have to readjust the angle of the miter gauge to cut left and right miters. You also can cut a miter by tilting the blade rather than angling the miter gauge. This procedure is similar, but

Illustration by Mary Jane Favorite

Miter gauge angled

there is an important difference when cutting left and right miters. As you rotate the board end for end, the same face must rest against the table. Note: You can switch faces if you first switch the miter gauge to the other slot.

Bevels The procedure to make a bevel is similar to the way you make a miter, but you must set the blade at the proper angle, rather than the miter gauge. Measure the angle between the blade and the table

When using a dado set and sacrificial rip fence to make rabbets, setting the height of the dado set in the fence is tricky. Make it simple by attaching a new sacrificial fence, then measure and mark the height of the blade (for the perfect rabbet depth) right on the fence face, measuring from the table saw’s top. Lower the dado set, move the fence into place, then bring the running blade up into the fence, stopping when you reach your line.

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with a triangle or a protractor. If you rip a bevel or chamfer, make sure the blade tilts away from the rip fence. This gives you more room to safely maneuver the board and reduces the risk of kickback. On right-tilt saws, you will have to move the rip fence to the left side of the blade (as you face the infeed side of the table saw).

Rabbets, Dados and Grooves Although the final results and applications for dados, rabbets and grooves are different, the way to make each is very similar. And all are easily made on the table saw. But first let’s take a look at the joints themselves. • A rabbet is an L-shaped cut of varying widths and depths, cut on the end (cross grain) or side (long grain) of a board. The width and depth of the rabbet can be adjusted to match the piece fitting in the rabbet, such as on a cabinet or drawer side. The joint created is better than a butt joint, but it is stronger when reinforced with more than glue. • Grooves and dados have the same shape, but they’re called different names depending on the direction they’re cut on the board. Both a groove and a dado are U-shaped trenches. The depth and width are variable according to the use. This joint is referred to as a groove when it’s made parallel to the grain direction of the board. When made across the grain, it’s referred to as a dado. This is a stronger joint than a rabbet because the mating piece is captured on three sides, rather than two. Using a Dado Set Rabbets, dados and grooves can all be created by making multiple cuts with a single saw blade, or one cut with a dado set. The different types of dado sets were discussed in detail in Chapter One of this series, as were the different saw blades to best use for this application. When changing from a single blade to a dado set, always remember to unplug the saw and carefully handle the sharp blades. Because a dado stack cuts a much wider kerf than the ordinary saw blade, you must replace the saw’s throat

8

When ripping an angle other than 0° – cutting a bevel or a chamfer – be sure the blade tilts away from the rip fence. If the blade tilts toward the fence, there is a chance that the blade will pinch the board and fling it backward. Also, you may not have the space needed to feed the board safely. And on narrow cuts, there is the added danger that the blade may bite into the fence.

RABBET

DADO

A rabbet (top) is an L-shaped cut on the end or side of a board. The depth and width can be varied to match a mating piece, or to create a particular type of joint. While the rabbet can be viewed as the female part of a joint, it can also be the male part, as it forms a tongue that can be used in tongue-and-groove joinery. A dado (bottom) is U-shaped and cut across the width of a piece. It can also be adjusted in depth and width. A groove is cut parallel to the board’s grain direction. It’s always the female part of a joint. Rabbets, grooves and dados can be “through” (run entirely across the board as shown), or stopped at either of both ends, depending on the requirement of the joint.

Because the dado stack makes a wider kerf than the saw blade, you must replace the normal throat insert with one that has a wider opening.

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A sacrificial fence attached to your rip fence allows you to accurately use part of a dado set for rabbeting without harming your rip fence. The blade should be run up into the fence while it’s securely locked in place to the tabletop. Make sure the blade clears your rip fence.

Featherboard

Featherboards, to hold material snug against the fence (and to avoid kickback), can either be shop-made or purchased. The featherboards shown here have magnetic bases to hold them tightly against the tabletop. They should be positioned before and after the blade, but not at the blades’ location or the waste will bind against the blade.

TIPS & TRICKS PRO TIP:

Controlling Large Panels

When using a miter gauge extension to cut off large, wide panels, clamp a block of wood to the extension to serve as a hold-down. This will keep the panels from tipping over the back edge of the table saw as you finish the cut.

GREAT TIP:

Burn an Inch When making a sacrificial fence for your rip fence (for cutting rabbets), make it 1" thick. This will make it easier to use the fence scale when setting the position of the fence – simply subtract 1" from the indicated measurement.

PRO TIP:

Clean in the Corners insert with a special dadoing insert. You can either make your own insert or purchase an aftermarket accessory to fit your saw. It’s wise to make or purchase more than one. After you cut the insert to accommodate your widest dado arrangement, it shouldn’t be used with a smaller-width setup that will leave gaps between the opening and the blades. When making rabbets on the table saw with a dado set, a sacrificial wooden face attached to your existing rip fence is a must. This face must have a semicircular cutout that’s the same radius as the dado cutter. The cutout face serves two purposes – it protects the rip fence during these operations, and it covers the unused portion of the dado stack when you don’t want to cut the full width. Your next step is to detach the splitter (and guard, when appropriate) from the

table saw and attach a featherboard to the table or wooden fence. Because you don’t use a dado cutter to cut all the way through a board, the splitter will just get in your way. Unfortunately, without the splitter and anti-kickback fingers, there is nothing to stop kickback, so be careful. Also, because the dado cutter removes more stock than a standard saw blade, kickback is more likely. To guard against this, use a featherboard. When making the rabbet cut, the board is most safely run flat on the table saw’s top. By virtue of this position, the height of the dado stack should be set to the required depth of the rabbet. The distance from the sacrificial face to the left side of the dado stack (the amount of blade exposed) will be the width. To make a groove (or dado, but only on wide boards for safety) the rip fence

After cutting a rabbet with a dado cutter or a saw blade, inspect the inside corner between the side and the bottom. These cutting tools sometimes leave a little waste, or “tang,” in the corner. You can quickly remove this with a scraper, chisel, bullnose plane or rabbeting plane.

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is adjusted to re-locate the groove where needed, and the dado stack height is set for the required depth of the groove.

A sacrificial fence attached to your rip fence allows you to accurately use part of a dado set for rabbeting without harming your rip fence. The blade should be run up into the fence while it’s securely locked in place to the tabletop. Make sure the blade clears your rip fence.

It’s possible to create a rabbet on a board with a single blade using only two cuts. The order of the cuts is important for safety, though. The first cut (left) must be made with the face of the board against the saw table. The second cut (right) must be made on edge, with the waste piece oriented away from the fence to allow the waste to fall harmlessly away from the blade.

Making Rabbet and Dado Joints with a Single Blade As mentioned, rabbets and grooves can also be made with a single saw blade if you don’t have a dado stack. Rabbets can most easily be made in a two-pass method. The blade height is set for the depth of the rabbet and the rip fence is set for the width of the rabbet (including the blade width in the setup). The board is then run flat on the table surface for the first cut. To complete the rabbet, the blade height is reset to just shy of the width of the rabbet, while the fence is set to cut away the depth of the rabbet. It’s a good idea to have the rabbet size marked on the end of the board to double-check your setup. The board is then run on edge against the rip fence. The order of these cuts is important. If the board were run on edge first, then on its face, the waste piece could be trapped between the blade and fence, and be kicked back at you at a very high speed. As shown above, the waste piece falls safely to the outside of the blade after the second cut. To make a groove or dado with a single blade is more a nibbling away process until the groove is complete. It’s easiest to start with the two outside passes that will define the groove’s shoulder, then make overlapping cuts between those kerfs to remove the waste material. While this process works, it won’t take too many single-blade dados to convince you that the investment in a dado set is a smart one. Expanded Techniques In addition to cutting basic dados, grooves and rabbets, there are many other useful ways these joints can be used. Here are just a few of the most common variations: Stopped Cuts

Sometimes you must halt a cut before it exits the end or edge of a board. To

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make a stopped rabbet, dado or groove, you must first know where the dado cutter starts to cut as the wood passes across the table saw. To find out, first adjust the cutter to the desired height and position the rip fence. Affix a piece of tape to the fence beside the cutter. Select a scrap with at least one square corner and place it on the infeed side of the table with the square corner against the fence and facing the cutter. Slide the scrap toward the dado accessory as you spin the cutter by hand (with the saw unplugged). When the teeth brush the scrap, mark the position of the corner on the tape. To find where the dado cutter stops cutting, simply place the scrap on the outfeed side of the table. Now that you know where the blade stops its cut, you can clamp a stop to the end of the rip fence to halt the cut. Determine the length of the cut required and set the stop block that distance from your infeed blade mark on the fence. Shiplap Joint

A useful combination of two of our joints in this chapter is shiplapped boards, which are often used as decorative (and sturdy) backs in cabinetry. The shiplap joint uses two interlocking rabbets (created on the long edges of the boards). The interlocking rabbets form a solid back that still has the ability to expand and contract with changes in humidity, without stressing the cabinet, or opening a gap between the boards. To add a decorative element, bevel the shiplapped boards at the mating edges. Tongue-and-groove Joint

A mating of a two-sided rabbet (forming a tongue) and a groove run in the long edge of a board forms the tongue-andgroove joint. Offering the same benefit against wood expansion and contraction as the shiplap joint, the tongue and groove also offers great strength as a mating joint. It allows long boards to stay parallel over long lengths. That’s why it’s most common application is in flooring to lock the board lengths tight against one another. This joint also plays an important role in frame-and-panel

TIPS & TRICKS PRO TIP:

Tested for Accuracy

Whenever you’re setting up the saw for a rabbet or groove cut, it’s always a good idea to make a test cut in a scrap piece before cutting good stock. Measure the position of the cut on the board with a ruler or tape measure. For even more accuracy, a dial caliper can measure the width and depth very easily.

PRO TIP:

Dados with no Splintering

Add Basic Joints to Make Complex Ones A rabbet is a fairly simply (and not all that sturdy) joint. How it’s used can make it much stronger. If the tongue of the rabbet fits into a groove or dado, greater strength can be achieved. In fact, one of the strongest joints in woodworking is the mortise-and-tenon joint. And a mortise is nothing more than a groove with closed ends, while a tenon is a double rabbet! To turn a rabbet into a tenon, you’re simply cutting a shallow rabbet on both sides of a board with a dado stack that’s wider than the dado cutter itself. Do this by making two or more passes. This seems simple enough if you have to make only one joint – make the first pass, move the rip fence or reposition the board on the miter gauge, make the next pass. But if you must make several precise copies of the same joint, use spacers to help position the boards, removing them one at a time as you make each pass.

Tear-out

Whenever using a dado stack to make a dado (across the grain), there’s a very good chance of tearing out the fibers on the face of the wood, whether solid wood, or plywood (see above). To avoid this, score or precut both sides of the dado with a sharp utility knife before making the cut. This cleanly separates the fibers before the dado teeth get a chance to tear them.

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SHIPLAP JOINT

With the dado set to the desired height (and with the saw unplugged) the board is pushed forward until the leading edge touches the dado teeth. Mark the board location on the tape. This is the “start” position of the cut.

TONGUE-AND-GROOVE JOINT

doors, but we’ll cover that in more detail in Chapter Six. Rabbet-and-dado Joint

With a rabbet on one side and a dado on the other, this joint makes a strong, but simple drawer joint. While a simple rabbet joint can be used as a drawer joint, the addition of a dado allows the rabbet to be firmly captured on three sides. This adds strength and stability to the 12

joint. And this joint isn’t only for drawer sides. Many drawer bottoms are slipped into grooves cut in the drawer sides to form an even simpler rabbet and dado. But wait – that makes it a tongue (the entire bottom is a tongue) and groove joint.

Illustrations by Len Churchill

The tape mark on the fence also indicates where the dado cut ends in the piece. For a more accurate dado, a block attached to the fence (located using the tape mark) provides a positive stop.

RABBET-AND-DADO JOINT

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CHAPTER • 2

Advanced Joinery BY NICK ENGLER

In the last chapter we discussed basic joinery on the table saw, including miters, bevels, rabbets, dados and grooves. In this chapter we’re going to take those concepts a step further. Essentially we’ll be using the same techniques. These joints simply require a little more thought before you begin. We’ll be looking at compound miters, tenons, dovetails, lock joints and splines. Each of these joints can be created using tools other than the table saw. Some might even argue that they can be made more easily on other tools. For example, compound miters can be easily created using a miter saw. Tenons, dovetails (with the help of a jig), lock joints and splines can be handily created using a router or a router table. But why buy extra machinery, tools and jigs if you don’t have to? All of these joints can be easily achieved with your best friend, the table saw. Compound Miters To start we’ll take a look at compound miters on the table saw. While regular miter joints are a mainstay in picture framing, if you want to make a more complicated, three-dimensional frame you need to cut a compound miter. Useful for much more than picture framing, the compound miter joint is probably most commonly used in forming corners for crown moulding. This joint can be accurately created on the table saw with just a little help from mathematics. To cut a compound miter on a table saw you need to both tilt the blade

PRO TIP:

1-2-3 Crown When adding crown moulding to a cabinet, start by cutting the compound miter on one end of the front piece, then allow plenty of length and rough cut the other end a bit long. Then cut the appropriate compound angle on both short return pieces for the sides, again leaving plenty of length to the back of the cabinet. Use one return moulding to align the front moulding (forming the complete compound miter), then mark the exact location of the second miter cut on the front piece. Attach the front moulding, then simply mark the square cut on the back of each return, make the cuts and attach.

and angle the miter gauge for each cut. When two boards are joined by compound miters, the boards slope, rather than rest on an edge or a face. This slope and the number of sides of the frame determine the necessary blade tilt and

the miter gauge angle. (See the chart at right to find the settings needed for different frames.) A standard crown moulding (fitting in a 90° inside or outside corner) commonly has a 45° slope. Reading our A DVA N C E D J O I N E RY

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TIPS & TRICKS PRO TIP:

Choose Your Blade

Fitting tenons into mortises can be a little tricky, but by using the right blade you can make it easier. If you know you can cut a tenon to fit perfectly, then using a ripping blade (or flat-bottomed dado) to form the cheeks makes good sense. But if you want to make your tenon oversized and sneak up on the final fit with a shoulder plane, you don’t want to have to plane too much material for fitting. Rather, use a crosscut blade to form your oversized tenon. The tooth configuration on the blade will leave a corduroy-type finish on the tenon cheeks with hills and valleys. Planing away only the hills to get a perfect fit is much easier.

SMART TIP:

Easy, Cheap Clamping You’ll notice I used simple tape to hold together my compound miter test at right. Tape can come in handy after the test as well. When you’re assembling odd-shaped pieces such as a six-sided compound miter shape it’s nearly impossible to put clamps on the piece. Go ahead and use tape instead. Lay the pieces to assemble with the miters facing down. Butt the joints together and put tape across the joint. Repeat this for all but the last joint. Then carefully flip the taped pieces, add glue and fold the shape, taping the last joint. The pressure exerted by the tape as the joints close will be plenty adequate to hold everything together.

To make a compound miter, angle the miter gauge and tilt the blade. Compound miters are used to join boards whose faces slope, such as crown moldings.

chart, for four-sided miters, we come up with a blade bevel angle of 30° and a miter gauge angle of 54.74°. Before committing to the compoundmiter setup called out on the chart, make a sample to check your angle. Cut some small scrap pieces using the recommended angles. Cut enough to complete your test shape. To make matching left and right compound miters, flip each board face for face so that a different edge rests against the miter gauge and a different face rests against the table when cutting each end. After cutting all the compound miters, tape the pieces together to com-

plete the frame and inspect the joints. If the joints gap on the inside, decrease the blade tilt. If they gap on the outside, increase the blade tilt. If the slope is greater than you expect it to be, decrease the miter gauge angle. If it’s less than expected as measured from horizontal, increase the angle. Just make sure you don’t change any one setting more than 1⁄2° between tests. Another way to calculate compound miters is with a scientific calculator (about $9 at most office supply stores) with SIN, COS, TAN and INV buttons. On some calculators, the INV button is labeled FUNC or the key is blank.

To test a compound miter setup, cut enough sample pieces to form your ultimate shape. Cut all the pieces to the same length so you can complete a small frame. Tape the parts together, then inspect the joints and measure the slope.

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Compound Miter Chart SLOPE°

4 SIDES BUTTED MITER BEVEL ANGLE ANGLE

4 SIDES MITERED MITER BEVEL ANGLE ANGLE

0

45

90

5 SIDES MITERED MITER BEVEL ANGLE ANGLE

54

90

6 SIDES MITERED MITER BEVEL ANGLE ANGLE

60

8 SIDES MITERED MITER BEVEL ANGLE ANGLE

90

67.5

90

5

45.11

3.53

54.1

2.94

60.09

2.5

67.58

1.91

10

45.44

7.05

54.42

5.86

60.38

4.98

67.81

3.81

15

45.99

10.55

54.94

8.75

60.85

7.44

68.19

5.69

20

46.78

14

55.68

11.6

61.52

9.85

68.73

7.52

25

47.81

17.39

56.64

14.38

62.38

12.2

69.42

9.31

48.59

49.11

20.7

57.82

17.09

63.43

14.48

70.27

11.03

50.68

42.14

50.68

23.93

59.24

19.7

64.69

16.67

71.26

12.68

52.55

35.93

52.55

27.03

60.9

22.2

66.14

18.75

72.4

14.24

30

62.81

24.56

67.79

20.71

73.68

15.7

32.8

64.97

26.76

69.64

22.52

75.09

17.05

30

49.11

35 40 45

54.74

30

54.74

50

57.27

24.4

57.27

55

60.16

19.21

60.16

35.4

67.38

28.78

71.68

24.18

76.64

18.26

60

63.43

14.48

63.43

37.77

70.04

30.59

73.9

25.66

78.3

19.35

65

67.09

10.29

67.09

39.86

72.93

32.19

76.29

26.94

80.07

20.29

70

71.12

6.72

71.12

41.64

76.05

33.52

78.83

28.02

81.94

21.07

75

75.49

3.84

75.49

43.08

79.35

34.59

81.5

28.88

83.88

21.7

80

80.15

1.73

80.15

44.13

82.81

35.37

84.27

29.52

85.89

22.12

85 90

85.02 90

0.44 0

85.02 90

44.78 45

86.38 90

35.82 36

87.12 90

29.87 30

87.93 90

22.43 22.5

Note: The slope is measured from horizontal, with the assembly resting on a bench or work surface.

Illustration by Len Churchill

Step-off block

Sandpaper

MORTISE-AND-TENON JOINT

Tenons When it comes to reliable joinery the mortise and tenon is excellent for frames, including table bases, doors and cabinetry. The male part of the joint, the tenon, is easily made on the table saw. First, the shoulders of the tenon are cut using a miter gauge to guide the workpiece. Depending on the required dimensions of your tenon, you may be able to make all four shoulder cuts without changing the saw setup.

Defining 3 ⁄16" shoulders on all four sides of a tenon is simple. The piece is run over the blade using a miter gauge. I’ve added sandpaper to the face of the miter gauge to keep the piece from slipping. I’m also using a step-off block that allows me to set my fence to align the cut, but as the miter gauge moves forward, the block stays behind to avoid kickback if the piece binds.

Traditionally a tenon is half the thickness of the workpiece. With a 3⁄4”-thick piece of wood that would require a 3⁄8”thick tenon. This leaves a 3⁄16” shoulder on the two wide sides of the tenon and that’s usually a perfectly good size for the two narrow shoulders as well.

With the shoulders defined it’s time to cut the cheeks. There are a few ways this can be tackled on a table saw, primarily either with the piece held vertically or horizontally. To cut the cheeks horizontally, a dado cutter works well and will accurately center the tenon.

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Cutting a tenon vertically on the table saw is really only safe if the piece is held tightly in place during the cut. A simple shop-made tenoning jig like the one shown here locks the piece in place quickly with the snap of the toggle clamp’s lever. My tenoning jig is designed to straddle my rip fence, adding even greater stability and control during the cut.

TIPS & TRICKS PRO TIP:

No-mortiser Mortise

PRO TIP:

Dedicated Dovetail Blade If you do a lot of dovetailing on the table saw, you may find it convenient to have a blade modified specifically for the task. Have your sharpener grind the teeth of a rip or combination blade so all the teeth are angled at 10° (be sure to indicate which way your saw tilts). This will allow you to cut right to the shoulder line on the tail board, saving a lot of handwork. You’ll still be able to use the blade for most regular work. – Excerpted from Cutting Edge Table Saw Tips & Tricks, by Kenneth S. Burton (Popular Woodworking Books).

16

Toggle clamp

Another advantage to using this accessory is that you can cut both a shoulder and a cheek in one pass. If you don’t own a dado cutter, a single blade can also be used by making repeated cuts to nibble away the waste. It’s slower, but it still works. To cut the tenon in a vertical manner I recommend using a tenoning jig that holds the piece tightly in place, as shown above. Another advantage to a tenoning jig is it also guarantees a centered tenon. The piece is flipped to cut both cheeks, but the jig remains in place, centering the tenon. You should always make a sample piece to test-fit the tenon to its mortise and adjust the setup as needed. While you can’t make a mortise on a table saw, you can make a variation on the traditional mortise-and-tenon joint known as the bridle joint. This joint leaves the mortise and the tenon visible from the ends of the adjoining boards. While not as strong as a true mortise and tenon, it greatly simplifies the mortising operation and both parts can be cut with a single setup on the table saw using a tenoning jig. The bridle joint shown at right is designed for joining a rail to the center of another piece. If the top piece were trimmed away at the left end of the joint, you could easily form the corner of a door frame. All of this can be done on

the table saw and without having to fuss with cutting a mortise.

Dovetails Dovetails on the table saw? Not possible! At least you might think so, but if you’re making through dovetails (dovetails that allow the joinery to be visible from both sides of the joint), it can be done. Jim Stack, an accomplished woodworker and author, shared his method for through dovetails on the table saw. The trick is all in a special sled specifically designed to keep everything aligned during the cuts. You still need to lay out your dovetails as your would with any dovetail jig, but with this method you’re not limited

Illustration by Len Churchill

Large through-mortises in furniture can be time consuming and require equipment (a mortiser and appropriate chisel) that you might not own. These types of mortises often occur in table legs and there you’re in luck. You can build the mortise into the leg and use your table saw to make it. Most trestle-style legs are too large to be cut from one piece of wood, so a glueup is required. By running matching, wide dados in the leg halves prior to glueup, you can make almost any size through mortise with a minimum of effort.

BRIDLE JOINT

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Table Saw Dovetails The table saw is great for cutting dovetails because it can cut straight and square. You can create the look of a hand-cut joint by using this two-sided sled and a rip blade. 1. Use three #6 x 3 ⁄4" wood screws to attach the hardwood miter guide to the bottom of the base at dead center. 2. Use #8 x 11 ⁄ 2" wood screws to attach the angled fences to their mounting cleats and cut a 10° angle on the each end. 3. Draw a line down the center of the base and screw the assemblies to the base. 4. Attach the blade-guard blocks behind the angled fences. Then put the jig in one of the miter slots on your table saw and

6. Attach the blade-guard blocks to the straight fence in the same manner that you did with the angled fence. Use glue and screws. 7. Set your saw blade so it’s square to the table and about 1" above the base of the jig. Cut a kerf into each angled fence. Don’t cut all the way through the blade-guard blocks. 8. Turn the jig around and bevel your saw blade to 10°. Cut this angled kerf into both sides of the straight fence. – Jim Stack

mark where the blade meets the base. Attach a blade-guard block behind the fence at this location. Put the jig in the other miter slot and repeat the process. 5. Screw the straight fence to its mounting cleat, then screw one end of the mounting cleat to the base, allowing the fence to pivot until you square this fence to the blade. With the jig in one of the miter slots, hold a framing square against the long fence and line up the other arm of the square with the saw blade. Screw the assembly in position.

Angled mounting cleat E Fence B

Miter guide F

41/2"

Dovetail Fixture NO.

LET.

ITEM

DIMENSIONS (INCHES) T W L

1

A

Base

¾

11½

28

Plywood

1

B

Straight fence

¾

28

Plywood

2

C

Angled fences

¾

14

Plywood

1

D

Straight mounting cleat

¾

2

28

Plywood

2

E

Angled mounting cleats

¾

2

14

Plywood

1

F

Miter guide

3∕8

¾

13½

Hardwood

4

G

Blade-guard blocks

2

3

Hardwood

Base A

28" 111/2"

DOVETAIL FIXTURE

TO CUT YOUR DOVETAILS:

Lay out the pins on the end and both faces of the workpiece. Be sure to mark the waste material. Set the saw blade height to the thickness of the stock. Using the angled fence on the fixture, make your defining cuts for one side of the pins.

Angled fence C

MATERIAL

1

Blade guard block G

Mounting cleat D

Illustration and photos by the author

2

Move the fixture to the other miter gauge slot, switch to the other angled fence and make the cuts on the other sides of the pins.

5

3

Nibble away the waste between the pins with repeated passes over the blade.

6

4

Use the pins as a template to lay out the tails.

Tilt the blade to 10° and turn the fixture around so the straight fence faces the blade. Raise the blade to the material’s thickness. Make the defining cuts on one side of each tail.

Flip the part face for face and make the defining cuts on the other side of the tails. Then clean out the waste. Clean out the corners of the tails with a chisel.

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TIPS & TRICKS PRO JIG:

Joinery Dividers Once you’ve mastered the lock joint, put it to work for the inside of the drawers as well. The same joinery technique can be used to add fixed dividers to any drawer or box. Simply space off the locations for the dado cuts, running both sides at the same time (to make sure they’re even). Then run the tenon cuts on as many dividers as you need. This same concept can be used for curio shelving.

PRO TIP:

Spline Grain Direction The grain in a corner spline should run across the joint for maximum strength. For a hidden spline, this means the length of the piece will be only about 3 /4", while the width will be considerably more. Rather than try to cut such a short, wide piece, make the splines from fairly narrow pieces and use as many as necessary to fill the groove. – Excerpted from Cutting Edge Table Saw Tips & Tricks, by Kenneth Burton (Popular Woodworking Books).

The first cut for the lock joint is made with the inside face of the drawer part flat against the table saw. The piece is slid snug against the fence to locate the dado 1 ⁄4" in from the end. The miter gauge must be set accurately at 0° and the fence exactly parallel to the blade to avoid binding.

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PO DUJ JSF F E MJO BJO TQ (S PG

A 1 ⁄4"-thick step-off piece is used to cut the tenon on the end of the drawer fronts and backs. Not only does this simple block add a bit of safety against binding, but it also allows you to make this second lock joint cut without having to reset the blade or fence.

FLAT SPLINE

PO DUJ JSF F E MJO BJO TQ (S PG

18

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by templates and you can make the pins as thin as you’d like without the worry of fitting a router bit into the opening. The page at right shows you how to make the jig and how to put it to work. I’m afraid we’re still working on a method to cut half-blind dovetails on the table saw.

Lock Joints Similar to half-blind dovetail joints, lock joints (or locking tongue-and-dado joints) cannot be seen from one direc-

tion and are often used to assemble drawers. They’re much easier to make than dovetails – you can cut them with a single setup on a table saw. The trade-off is that they don’t withstand shear stress as well as dovetails (the wood in front of the dado will shear off if you pull too hard on the drawer front). However, they are still a good choice for small drawers or drawers that won’t see much use. To make a lock joint, mount a dado

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Splines A spline is a small board, usually just 1⁄4” to 1⁄8” thick, that spans the joint between two boards. The spline rests in two matching grooves – one in each board. You also can install a spline in matching rabbets or dados if needed. Splines can be made of solid wood, plywood or hardboard. Solid wood is best if the spline is decorative and the grain runs perpendicular to the joining pieces. Plywood is excellent when the top plys run with the grain of the joint making a good glue surface while the cross-grain plys add strength. Hardboard, which has no grain direction, is good for any grain direction. Making a spline groove is no different than making an ordinary groove. Use a saw blade or dado cutter to cut a groove as wide as the spline is thick. Cut

Illustration by Len Churchill

the depth about 1⁄32” more than half the spline’s width to allow excess glue space. If centering the spline is necessary, simply run the board twice with opposing faces against the fence. Start with the blade near center on the edge, then sneak the fence over till the groove is exactly the right width. Dry-fit your spline. Half the spline should fit in one groove and half in the other, with just a little side-to-side slop. If everything checks out, spread glue on the adjoining surfaces, the splines and in the grooves, and assemble the joint. The advanced spline joint is one used to reinforce miter joints. Depending on how a miter joint is oriented, you can run the splines either horizontally or vertically. Also, you can choose whether to cut the spline before or after you assemble the miter joint. Splined miters in which the grooves are cut after the parts have been assembled are sometimes referred to as open spline joints, because both ends of each spline are clearly visible.

LOCK JOINT

Illustration by Len Churchill

cutter on your saw and adjust the depth of cut to equal half the thickness of the board. As most drawer boxes are made of 1⁄2”-thick material, make the tongue and the thickness of the dado 1⁄4” thick. This works out fairly well for the dado stack as well, requiring only the two outer blades to make a 1⁄4”-wide dado. And as an added benefit you can actually set the saw and fence once for both cuts. Using the fence and your miter gauge to guide the stock, cut the 1⁄4” x 1⁄4” dado in the workpiece. The stock is held flat against the saw table and snug against the fence face. To cut the mating tongue section, you essentially want to shift your dado cut to the end of the board, rather than 1⁄4” in from the end. To do this, use a 1⁄4”-thick spacer against the fence. Set the tongue board flat on the saw table as before, using the miter gauge again as your guide. Slide the board against the 1⁄4” spacer and then push the board forward toward the blade. The spacer remains behind, leaving a 1⁄4” space between your board and the fence face. Hold the piece tightly against the miter gauge and make your cut. That’s all it takes – you have your 1⁄4” x 1⁄4” tongue that should fit your dado perfectly.

SPLINE JOINT FOR FRAMES

For splines, make a quick carriage to help support the assembly as you move it past the blade. The blade height should be just shy of the joint’s inside corner. For flat frames, you can saw right through the carriage’s supporting pieces. Just be sure no screws are in the path of the blade. – Excerpted from Cutting Edge Table Saw Tips & Tricks, by Kenneth Burton (Popular Woodworking Books).

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CHAPTER • 3

Router Joinery BY NICK ENGLER

Although routers were originally designed to create moulded shapes, they can be excellent joinery tools. In fact, they’re better in some ways than table saws, professional-quality mortisers or dado cutters when it comes to cutting joints. There are several reasons routers have an advantage: • Simplicity: Setting up hand-held or table-mounted routers is rather straightforward. Tools dedicated to joint-making such as hollow-chisel mortisers are more complex and require more time to set up. Sure, it could be worth the effort to use a mortiser if you’re planning to make dozens of duplicate joints. But if all you want to cut are a few mortises and tenons, for example, a router will save you loads of time. • Versatility: You can make a greater variety of joints with a router than with any other joinery tool. No matter if you have a fixed-base or plunge router, you can cut more types of joints than with any other kind of tool. • Accuracy: There isn’t a more precise joinery tool. You may find tools just as accurate, but none that surpass the router. Because routers cut quickly, they leave a smooth surface, meaning joints fit better and bonds are stronger. There are some disadvantages to using your router for joint-making, and I’d be remiss if I didn’t mention them: • Most routers won’t stand up to continual cutting as well as heavy-duty woodworking machinery. • Because you can’t make deep cuts in a single pass on a router, it may take you longer to rout some joints than it would 20

PRO TRICK:

Dehumidifier Can Make Your Tenons Fit Tighter Woodworkers who use mortise-and-tenon joints sometimes keep a dehumidifier in their shop to make it drier than the surrounding environment. Once in the shop, wood shrinks slightly. Then, when a completed project is returned to normal humidity, the tenons swell in the mortises, making the joints tighter.

to use a mortiser or dado cutter. • Depending on the joint you want to make, you may be limited by the sizes and configurations of available bits. These shortcomings, however, are minor. Routers are indispensable joinery tools in any workshop.

Rabbets, Dados & Grooves You can make the most basic woodworking joints – rabbets, dados and grooves – using a simple fixed-base router and an inexpensive set of straight bits. Rabbets (and the simple tongue for a

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When routing dados and grooves, the joint ordinarily will be the same width as the bit. If you need to make a joint of a larger size, first make a cut that’s somewhat narrower than the joint needed (left), then move the fence or straightedge to make a second cut (below), enlarging the joint to the desired width.

TIPS & TRICKS PRO TRICK:

Tilting Pieces to Create Stopped Cuts

Bit locations marked on fence

Stopped grooves or dados can be made safely on the router table by first marking the bit location (both sides of the bit profile) on the fence, then carefully lowering and raising the piece for the cut using the end of the board opposite the cut as a fulcrum.

PRO TIP:

No Templates Needed If You Copy an Existing Piece tongue-and-groove joint) are produced easily with a router. While you may need a variety of rabbet sizes, a single rabbeting bit can accomplish them all. By purchasing a rabbeting bit with interchangeable guide bearings, the width of the rabbet can be changed quickly by selecting and installing a different diameter guide-bearing on the bit. Rabbeting can be accomplished safely using a router free-hand or in a table. For rabbeting smaller pieces (such as with frames or door mullions) I recommend using a router table. In a table, you can use a simple straight bit to cut the rabbet, or you can use a rabbeting bit with a bearing guide. Even though you may think the bearing guides make a fence unnecessary, you still should use one to limit the amount of bit exposed and to help guide the pieces. Align the fence with the outside edge of the bearing for a seamless process. For improved accuracy and safety, use a fingerboard to hold the material against the fence and table. As mentioned earlier, a rabbet also

can form the tongue for a tongueand-groove joint. The tongue can be flush to one side of a board (for offset raised-panel doors) or the tongue can be centered on the board. Essentially, the tongue is just a long tenon. Run the groove first, then simply size the tongue to fit in that groove. Many dados or grooves can be made with a straight bit that is sized to accurately make the joint with a single-width pass. To make a dado or groove that’s a non-standard size, choose a cutter that’s slightly smaller than the width of the joint and cut the joint in two passes, as shown in the photos below. Because most basic joints are cut parallel or perpendicular to straight edges, you must guide the router or the work in a straight line. The best way to do this is to use an edge guide, straightedge, fence or miter gauge. You also can use a shopmade jig. If the joint is blind (which means it stops before running through the board) at one or both ends, attach stops to the workpiece or the guides to automatically

To reproduce a shape quickly and precisely without making a template, just use an existing part to make copies. Adhere the shaped part to the stock with double-faced carpet tape and, using either a pattern-cutting or flush-trim bit, cut the stock while tracing the shaped part with the bearing. However, because the bit won’t cut inside corners that are smaller than the bit diameter, you’ll have to cut this with a band saw or scroll saw.

GREAT TIP:

Mortising Bits are Worth Taking the Plunge For Some manufacturers offer so-called mortising bits. They look like a standard straight bit with one difference: They have an additional small cutter at the end of the bit. This bit allows you to plunge directly into your work, instead of wiggling the bit as you plunge, which is typical with a straight bit.

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Stop block

When cutting blind joints – rabbets, dados and grooves that are closed at one or both ends – use a stop block to halt the cut at the blind ends. Note that the end of the stop block is mitered. This prevents sawdust from being trapped between it and the stock, where the dust might interfere with the accuracy of the cut.

When cutting a joint in a contoured edge, use a piloted bit to follow the contour. A piloted rabbeting bit will neatly cut a rabbet in an irregular edge, while a spline cutter will likewise make a groove in an irregular edge a simple task.

22

halt the cut. The location of these stops depends on where the joint is to be cut in the board. For example, to cut a blind groove that stops 6” from the ends of the board, clamp a stop to the outfeed side of the fence 6” from the router bit. Now, if the joint is blind at both ends, you can determine the distance between the two stops by adding the length of the board to the length of the joint and subtracting the router bit diameter. (For example, if you want to cut a 4”-long double-blind groove in a 10” board with a 3⁄ 8”-diameter straight bit, position the stops 135⁄ 8” apart.) But what if the rabbet must follow a contour? Well, there are a couple of choices, but the only bit that makes good sense for making contoured rabbets is a bearing-piloted rabbeting bit. For a contoured groove, a different approach will likely be necessary. The answer this time is a guide collar (also called a template guide) and a template. Because a guide collar is slightly wider than the diameter of the bit, the contour cut by the router will not be the same size as the template. For inside curves and corners, the contour will be smaller; for outside ones, it will be larger. There always will be a small gap between the edge of the template and the nearest side of the cut because of the different diameters. To determine the width of this space, subtract the diameter of the bit from the outside diameter of the collar and divide by two. (For example, if you cut a contoured groove with a 5⁄ 1 8”-diameter collar and a ⁄ 2”-diameter bit, the distance between the template and the groove will be 1⁄ 16”.)

Mortises and Tenons To make a mortise and its matching tenon, you must combine several techniques. Although it may seem complex, a mortise-and-tenon joint is just a combination of several basic joints. After all, a mortise is simply a groove that’s blind at both ends, and a tenon is made by cutting two or more rabbets in the end of a board. The trick to cutting precise mortises and tenons is to make the cuts in the proper order. Most experienced wood-

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Scrap Cheek Shoulder

To make a tenon, cut two or more rabbets in the end of the board – these rabbets will become the cheeks and shoulders of the tenon. To fit the tenon to the mortise, cut the tenon just a bit large, then slowly raise the bit, shaving away a paperthin layer of stock on each cheek until you get the fit you’re after. Guide the cuts with the miter gauge, using the fence as a stop.

On half-blind dovetails (above), the joint is hidden from view on one side. This makes it ideal for the fronts of drawers and other applications where you don’t want to see the joinery. Through dovetails (right) are visible from both sides and are often used for decoration, as well as joining.

workers agree that it’s easiest to cut the mortise first, then fit the tenon into it. To make a mortise, you must bore a starter hole and expand it to the dimensions needed. There are several ways to do this using a fixed-base or a plunge router, either hand-held or in a table. However, when you make mortises for mortise-and-tenon joints, you usually want to make several mortises in different workpieces, all the exact same size and shape. The easiest way to accomplish this is with a simple template. As a general rule, mortises should

be about half the width of the material they’re made in. So a mortise in a 3⁄ 4”wide piece of wood should be 3⁄ 8” wide, with a 3⁄ 16” shoulder on either side of it. The depth of the mortise should be no less than 3⁄ 4” to ensure a good joint, but 1” or slightly more usually is a good idea. The simplest form of template is a piece of plywood that has a hole in it that is the exact size of the mortise you wish to rout. Just clamp the template directly onto your work and then form the mortise using a straight bit that

has a bearing above the cutting flutes. There are a variety of ways to make the template, from making plunge cuts on a board with a table saw to edge-gluing four pieces of wood together and leaving a gap in the middle that is the size of the mortise. All work just fine. When cutting the mortise, first plunge straight down in the area you wish to waste away. Then, with the router fully plunged, follow the template’s edge with your bearing to shape the mortise to its finished size. (See below for how to cut the tenon.)

Dovetails There are three basic dovetail joints: half-blind dovetails, through dovetails and sliding dovetails. The router is the only power tool that can create them all, using a special dovetail bit. Both half-blind and through dovetails are most easily made using accurate templates. These can be purchased (there are many commercially manufactured ones) or you can make your own. Through dovetails require two passes and two matching templates. These templates are less common than half-blind dovetail templates and, because of the precision required to make them, can be much more expensive. Sliding dovetails require no special equipment, other than your router, router table and dovetail bit. To make a sliding dovetail, first rout a dovetail slot the same way you would rout a dado or groove. Because of the bit shape, however, you must cut the full depth in one pass. Next, cut a dovetail tenon to fit this slot – this must be cut on a router table. The slot, on the other hand, can be cut using a hand-held router. Leave the depth of cut unchanged from the setup you used when routing the slot. Then pass a board by the bit, cutting one face. Then turn the board around and cut the other face. These two cuts form the tenon. To assemble the joint, just slide the tenon into the slot. If necessary, adjust the fit by trimming a little stock off the tenon’s cheeks, either with your router, a small plane or simply with sandpaper.

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When using a fixed through-dovetail template (left) you can’t change the size and position of the tails and pins. Rout the tails first, using the tail template, a guide collar and a dovetail bit. Then you can switch to the pin template and a straight bit. Fit the pins to the tails by moving the template forward or back on its holder. This will change the size, but not the location, of the pins.

Coped Joints Perhaps the easiest way to make a joint with a router is to cut a “coped” joint, where both adjoining surfaces are shaped. The most common example of this is on cabinet doors where the rails (the horizontal pieces) meet with the stiles (the vertical pieces). Each joint surface is a mirror image of the other, so the two surfaces mate perfectly. This has two advantages: the shape of the joint aligns the adjoining parts so the surfaces are flush and the corners are square, and the shape increases the gluing surfaces and strengthens the joint. Coped joints require special router bits that can be pretty expensive. There are three types of bits, and each must be used in a different manner: • Single bit with one cutter: The male and female cutters are on the same bit, making it a long piece of tooling. You raise and lower the bit in the table to change which set of cutters are in use. • Single bit with interchangeable cutters: You switch from the male to the female cutter by disassembling the bit and changing the orientation of the cutters. There are small shims involved so you need to keep those in the right place as you assemble the bit each time. • Two bits: There’s one bit for cutting 24

To rout a half-blind dovetail joint (right), secure both of the adjoining boards in the template. The “tail” board is held vertically, so its end is flush with the top surface of the horizontal “pin” board. Cut both the tails and the pins in one pass with a dovetail bit, using a guide collar to follow the template.

A drawer-lock joint requires only one bit and one setup. However, instead of reversing boards face for face as you cut them (like in the finger glue joint), you must cut the drawer front with the face of the workpiece against the router table, and then cut the drawer side with the face against the fence. Adjust both the depth of cut and the position of the fence so the members fit together properly.

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the male part of the joint and a second for the female. This is usually the most expensive route. There is another type of bit used for assembling boxes that routs the joinery on both edges. The drawer-lock joint – one example of these – is shown below.

Loose-tenon Joints Along with all the joints we have discussed so far that require joinery parts cut on the mating pieces, there are a number that use an extra piece to form a loose-tenon joint. The three most common are the true loose-tenon joint, the spline joint and the biscuit joint. The true loose tenon is exactly what it sounds like. Rather than making a mortise in one piece and a tenon on the other, both pieces have mortises. A third piece (often made in a long stock piece and cut to length) becomes a double-sided tenon, connecting the two mortises. The strength is essentially the same as it is in a mortise-and-tenon joint, but the process is perfect for use with a router, and it is quick and accurate. The mortises are made as described earlier and can be left rounded on the ends, as created by the bit. The tenon is made from a piece of stock planed and ripped to fit the mortises. Next the four

arises are rounded using a roundover bit in your router to make a perfect fit in the mortises. Then you simply crosscut the tenon to fit the mortises. Spline and biscuit joints are cousins to each other. The spline joint requires a groove (usually about 1⁄ 4” wide) that you run the entire length of the two pieces to join together. This can be an edgeto-edge joint or an edge-to-face joint. It doesn’t matter. A special router bit called a splinecutting bit is used to cut the groove. As with a rabbeting bit, the spline cutter uses interchangeable bearing guides of different diameters to adjust the depth of cut. A router table’s fence also can be used to adust the depth. With the mating grooves cut, just glue a spline in place. The spline can be made from 1⁄ 4” plywood or solid wood, depending on your preference. Again, the spline should be slightly less wide (deep) than the groove to allow some room for glue squeeze-out. Biscuits follow the same concept, except the spline cutter is used to cut shorter grooves and commercially available biscuits are used to bridge the joint. In essence you’ve replaced the need to buy a $150 biscuit jointer with a $20 router bit – not too bad.

A BIT OF ADVICE A router bit consists of a cylindrical shank (1⁄ 4" or 1⁄ 2" in diameter) and one or more flutes or cutting wings, usually comprised of a piece of carbide brazed to the metal body of the bit. Throughout this series, we will be providing a closer look at many of the common and specialized bits that can be used with your router. These three bits are great when using your router for joinery.

Rabbeting Bit This handy bit usually comes with a set of different-sized bearings that you can simply swap out to cut rabbets of different depths.

Cope-and-stick Bit Making decorative frame-and-panel assemblies is a snap with this bit. There are three versions that have different ways of approaching the same operation. In this version, one bit cuts both the male and female pieces.

Spline-cutting Bit

A tongue-and-groove joint requires two matching bits. Rout a groove in one edge of each of the workpieces, then change bits and rout a tongue in the other edge. You must carefully adjust the depth of cut for the second cut to match the first so the faces of the adjoining boards will be flush.

Making grooves in edges is the mainstay of this bit. Newer versions allow you to adjust the size of the groove with shims or by adjusting the cutters.

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CHAPTER • 4

Case Joinery B Y D AV I D T H I E L

Face Frame or Frameless? Before we dive into the joinery, let’s take a moment to review the two main types of case construction. Case pieces can be built with just the sides, top and bottom, with an optional back – this is called a frameless design. Carcases can also be built with a rigid front frame (formed of stiles and rails) added to the front of the box for extra strength (and it does offer a different look, too). The type of casework construction you choose, face frame or frameless, will help direct you to the proper joinery. In general, a frameless cabinet requires stronger carcase joinery, while a cabinet with a frame can rely more on the frame for strength and use less stout joinery for 26

the carcase. There are, of course, joints that work for both types of cases. And because we’ve mentioned frames, we need to look at two distinct categories of joinery as well: Joinery for box construction (frameless), versus joinery for the construction of the frames themselves. While a dovetail is an excellent carcase joint, it’s not a practical frame joint. Similarly, a mortise and tenon is an excellent joint for frames, but is usually impractical for box building.

Box Joinery Without Frames Let’s take a look at some of the joints that are best used when building a case piece that is purely frameless. The chart at right offers a good/better/best comparison of some of these joints. Some of the joints that aren’t represented on the chart are the more mechanical joints, i.e. screws. Screws all by themselves can be used to hold cabinetry together fairly successfully. The difficulty being they’re not very attractive. In a utility cabinet, that’s not a

Photo by Al Parrish

In this chapter we’re going to take a look at many of the most practical joinery possibilities for building casework furniture.As you might imagine, this is a huge topic. Casework runs the gamut from jewelry boxes to kitchen cabinetry, and there are literally dozens of ways to form the cases. Some are traditional joinery methods, such as rabbets, dados and dovetails. Others involve more contemporary mechanical fasteners, such as wood screws, pocket screws and biscuits. Because of the volume of joinery options, we’re only going to be able to briefly discuss the different types, the benefits and deficits of each joint and what casework application each joint is best suited for. What we won’t be doing is showing you how to make each joint. But plenty of woodworking books can help you with this part of the equation.

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The shelf is fit into a dado, resulting in much better strength than a simple butt joint. By adding a peg or two to the joint, you add even more strength and the opportunity to add a visual element to the piece. In this case it’s the proverbial square peg in a round hole. A hole is drilled through the side and into the shelf. A piece of square stock cut to the diameter of the hole is then tapered at one end and driven into the hole. When fully seated in the hole, the peg is cut flush to the cabinet side and sanded smooth. The result is the appearance of a square peg and lots of extra strength.

These two examples of joinery would work well for a case piece without a frame. The photo on the left shows plywood construction, reinforced and aligned with biscuits. To add an even stronger touch, a pocket screw is inserted through the bottom and used to pull the joint tight. Veneer tape will hide the plywood edge. At the right, a solid lumber piece is built using a rabbet and dado joint for the top, bottom and shelves.

problem, but it’s not what you want in a piece of fine furniture. You can countersink the screw and add a plug, but you’ll still see the plug. If the arrangement of the pieces allows, pocket screws (below left) are an option. By placing the screws on the underside of pieces, the screws essentially disappear. Or, these holes can also be plugged, as with a standard screw hole. Another mechanical fastener that should be discussed is nails. Whether fired from a pneumatic nailer or knocked in with a hammer, there’s lots of commercial furniture that is held together with nails. As with screws, placement

is critical for visibility. Nails will add strength to a joint, but not as much as a screw. It’s probably better to think of a nail as a fast clamp while the glue dries. Pneumatic nails do have one benefit over wire nails: The surfaces of the brad nails are coated with an adhesive to hold the clips of nails together. One positive side benefit of the adhesive is that as the nail is driven at speed into the wood, the adhesive heats up, softens and actually serves to glue the nail into the joint. The more traditional approach to assembling a carcase is to use a wood joint such as a rabbet, dado or dovetail. As you look at the chart, the most obvi-

ous piece of information to be gained is that the more complicated the joint, the better it holds. Why? Two reasons. First, as you “complicate” the joint what you’re really doing is adding gluing surfaces to the joint. While a butt joint has one surface meeting another, a dado joint has three surfaces in contact between the two pieces. You also gain different grain orientation in the joint, which further adds to the gluing strength. Second, when you move into the most complicated joints you gain locking strength in the wood itself. Dovetails and locking miters are two very good examples of this strength. Even without ARTS & CR AF TS BUFFE T

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Casework Box Joinery

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T-BUTT

BUTT WITH BISCUIT

SLIDING DOVETAIL

LOCKING MITER

A standard joint for cabinetry, this is a simple but weak joint that requires little investment in terms of time, machinery or tools.

Adding reinforcement (biscuits as shown, dowels or screws) to a butt joint improves the joint’s strength.

A sliding-dovetail joint effectively locks the two pieces together for great strength. This joint can be stopped (as shown) or through.

This joint is an improvement over a miter joint, without adding a biscuit or spline. It offers greater gluing surface and strength.

CORNER BUTT

RABBET

RABBET AND DADO

HALF-BLIND DOVETAIL

The same simple joint can be used in the middle of a case piece (top) or to form a corner as shown directly above.

A rabbet joint offers more gluing surface than a butt joint and also adds better support to a corner joint.

By locking the rabbet in a dado, the strength and protection against racking on this corner joint are greatly improved.

No joint provides as much strength as a dovetail. This joint can be partially visible (as above), completely visible or completely hidden.

MITER

SPLINED MITER

DOVETAILED MITER

GROOVE AND PANEL

This traditional box joint hides end grain. With most casework, the joint will be short-grain-to-short-grain, which offers very little strength.

Adding a spline to a miter joint increases strength and improves alignment. It also provides the opportunity for an artistic element.

This joint offers visible joinery, but shows only a miter on the edges of the box, which makes it both attractive and strong.

When it comes to adding a back to a case piece, this joint offers strength and convenience. For a removable back, a rabbet is preferred.

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Illustrations by Len Churchill

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because you’re taking material away, it’s more difficult to keep the strength in the cabinet. That’s where the sliding dovetail comes into play. By cutting a dovetail-shaped socket in the cabinet sides and a matching tail on the ends of the drawer divider, a much stronger and lighter case is possible.

Box Joinery With Frames Now that we’ve shown that frameless case pieces can be built with joinery that provides excellent strength, why would we want to add a frame to the case? Two simple reasons: strength and aesthetics. While many case pieces are designed to sit on the floor, such as a dresser or chest of drawers, there are many examples of beautiful wall cabinets that hang suspended without any support below. If your wall cabinet is going to store books or dishes, you’re going to need all the strength you can get to counteract

Photo by Al Parrish

glue, the sheer mechanics of interlocking pieces of wood adds significant strength. You’re doing the same thing by adding dowels or biscuits to a joint – increasing interlocking strength and increasing the gluing surfaces. One case joint that I want to focus on for a minute is a sliding dovetail. This is a complicated joint to create, but well worth the effort. And with the proper steps most of the complication can be removed or at least minimized. A sliding dovetail joint adds tremendous locking strength between a divider panel and case sides, or when using a web frame to complete a case. It not only provides strength to pull the two sides together, but protects against racking (corner-to-corner motion). Full-depth drawer dividers aren’t always necessary in a cabinet. To decrease weight, you can use a dividing rail at the front with drawer runners along the side to guide the drawer. But

This drawer cabinet uses sliding dovetails on the drawer divider rails to reduce weight while maintaining case strength. Sliding dovetails can be tricky to execute, but with the proper setup and a little practice, they’re a handy option for a need such as this.

Cabinetmaker Troy Sexton understands the best of all worlds. The dresser he’s assembling is made of sections that are of frame-and-panel construction. This is a frameless cabinet, so Troy had to be certain of the strength in his joinery. He used the same cope-and-stick shaper knives to form the joints for the visible outside panels and the interior dividers. To assemble the case, he cut dados in the panels to add joint stength. At left, he’s using a brad nailer to hold everything together while letting the glue dry. Finally, he nailed on the back, held in place by rabbets.

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Porter Cable FF-size biscuit $-

11⁄2" slot length Rail

3⁄8" x 11⁄2" fluted dowel

11⁄4" selftapping screw Stile

1" dowel centers

Rail

Rail Stile

Stile

Biscuit joints can work well in face-frame joinery, but don’t assume you can use a #20. You need a smaller biscuit so the joint won’t show.

Dowels are a decent alternative for joining face frame parts, but they can be tricky to align to get the faces perfectly flush.

Pocket screws add lots of strength to a face frame joint. And unlike other types of screws, these are easily hidden on the inside face.

gravity. That’s one good reason to add a frame to an already strong case. The second reason is aesthetics. Sometimes a traditional cabinet you’re building calls out for a face frame. Even if strength isn’t a concern, the look of a face frame can dress up what some might call a plain piece of furniture. If you’re adding a face frame for looks, then strength isn’t your first concern and

so the joinery used on the frame itself can be of many different styles.

the strength and appearance requirements. In some instances a butt joint is possible on a face frame. This would be one of those aesthetic situations where a case is already plenty strong on its own, but you want the look of a face frame. The frame is then simply glued or nailed to the case and the stiles (the vertical pieces) and rails (the horizontal pieces) are

Face-frame Joints Face frames on cabinets are close cousins to frame-and-panel doors. Many of the same joinery options are available for face frames as are used in making doors. To determine what joint is best for the application, you need to look at

Through dovetails

Rabbet

Illustraton by Len Churchill

Mortise & tenon

At left is a diagram of a hanging wall cabinet. When a case piece like this is hung on a wall, strength becomes an important factor. With no floor to support the weight, the joints have to be even more reliable. This piece uses strong joints in the box itself, with through-dovetails at the corners of the case. The solid wood back is rabbetted into the case, then fastened by nails. The face frame is assembled with mortise-and-tenon joints in the corners then glued to the box. The frame-to-case strength can be increased even more by pegging the frame in place. There is a lot of strength in this cabinet’s joinery.

Through dovetails

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Rail Stile

butted together. While this is frequently done in commercial furniture, I’m going to suggest you go a step further (as a woodworker, you owe it to yourself). The butted ends can move over time leaving a sloppy-looking joint. Some modern mechanical options for face-frame joinery include biscuits, dowels and pocket screws. All will add strength and even accuracy in aligning the pieces at the joint. Nails (air-powered or not) aren’t a good option with face frames as they’re likely to split the wood when you work near the ends of boards. Beyond the mechanical options, some interlocking joints that work well include a half-lap joint or bridle joint. These joints offer a reasonable gluing surface to hold things tight over time, but are still fairly quick to create. The strength is moderate, but certainly better than a butt joint. Because we’re speaking of aesthetics, consider using a lapped dovetail. This variation on the half-lap adds an interesting visual element and also adds some strength to the joint. But when it comes to making a face frame for strength, the mortise and tenon is the way to go. This joint has been around for millennia – really! And it can be easily created with a router alone, a mortiser and table saw, or with simple hand tools. To make sure your mortise-and-tenon joints are as strong as possible, here are a few rules to follow: 1. If you’re using a mortiser to create

Rail

Intermediate rails

Stile

Loose tenons are a simple option over the traditional mortise and tenon. While you still need to machine the mortise (two in fact), this is more easily created on a drill press or plunge router with a straight bit, tools you likely already own. The tenons themselves are easily created in bulk using the table saw and a router.

your joint, the tenon thickness should be one-half the thickness of the stock piece. So if you’re using 3⁄4”-thick material, the tenon should be 3⁄8” thick. For creating the joint with a mallet and chisel, onethird the material thickness is preferable. 2. To avoid tearing out the wall of the mortise at the end of the joint, set the mortise (and the tenon) back from the end, leaving at least a 3⁄8” edge shoulder on the tenon. 3. In general, the tenon length in casework should be no shorter than 1”, and 11⁄4” is a reasonable length. If you’d like to consider another option to the standard mortise and

tenon, how about a loose tenon? The beauty of this joint is that the mortises can be made in a drill press and the loose tenon pieces can be run off in mass quantity on a table saw. Then the tenon edges can simply be rounded with a router. This joint offers the same strength as a traditional mortise and tenon without quite as much fuss. The mortise-and-tenon joint does one other thing that a face frame is very good at: it keeps the cabinet square. A mortise-and-tenon joint (when properly constructed) is a very rigid, square frame and you can actually use it to square up a cabinet that may have joinARTS & CR AF TS BUFFE T

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Illustration by David Thiel

Intermediate stiles

Photo by Bill Hylton

When talking about face frames for cabinetry, it’s a good idea to know what to call all the pieces. The outer vertical parts are stiles (and always run through), while the horizontal parts are rails (and always run between stiles).Of course, there are circumstances where other terminology is necessary. When stiles and rails are within the perimeter of the frame they are intermediate stiles or rails.

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Casework Frame Joinery GOOD

32

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BUTT

BUTT WITH DOWELS

MORTISE AND TENON

T-LAP DOVETAIL

This joint really doesn’t belong in the “good” category. It’s structurally weak and provides poor glue adhesion.

Adding a mechanical fastener (spline, biscuit or dowels as above) greatly improves the strength of this corner joint.

The ultimate in frame strength, the mortise and tenon guards against racking, is strong with lots of gluing surface and is invisible.

Better than a half-lap, the dovetail lap adds locking strength for either a corner joint or mid-rail joinery, but requires even more accuracy.

MITER

MITER WITH BISCUIT

MITER WITH SPLINE

COPE & STICK

A corner miter offers slightly better strength than a butt joint because of the short-grain match, but it still won’t hold up to much abuse.

Biscuits offer improved strength and alignment for what can be a tricky and weak corner joint. Dowels are also an option here.

Another way to strengthen a corner miter is with a spline. Beyond the adding gluing surface, a spline can be used as a decorative element.

Frames in casework needn’t always be plain. A frame-andpanel design dresses up a piece and adds strength.

HALF-LAP

CORNER BRIDLE

HAUNCHED MORTISE

A good corner joint, the half-lap adds strength and more gluing surface, but requires accurate machining and is a very visible joint.

Better than a half-lap, the bridle joint offers greater strength, more gluing surface and security against racking.

A variation on the mortise and tenon, this joint allows a panel to be added into the assembly with less work than a cope-and-stick joint.

WEDGED THROUGHTENON

A great visual element and very strong, the wedged throughtenon takes some practice but adds amazing strength.

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Photo by Al Parrish

ery that allows more play than is preferable. I mentioned cope and stick. This is a joinery technique most often reserved for doors because of the edge detailing accompanying the joinery. But this joinery technique can be used for cabinet sides as well, to excellent effect. With the face frame complete, it needs to be attached to the cabinet. In most cases glue and clamping work fine, but a couple of brad nails can help as well. You could also use biscuits or pocket screws if you feel alignment help or quicker assembly time is a benefit. Back Joinery Now that we’re at the back end of the article, I should say a couple of words about back joinery (sorry – couldn’t resist). One of the most common methods of adding a back to a case piece is by milling a rabbet at the back edge of the sides, top and bottom. The rabbet can be adjusted in width to accommodate 1⁄4” plywood backs, or 1⁄2” or 3⁄4” solid backs, depending on your requirements. One tip: if you’re making a large case piece that will be mounted to the wall, it’s a good idea to recess the back slightly (1⁄4”). Thus, any imperfections in the wall won’t keep the cabinet from fitting tightly against it. If you’re using a solid back, there’s joinery that will help span what can be

The cope-and-stick joint is a standard for most frame-and-panel doors. But the same joint can be used to create panels for casework. The profile on the cope and stick can vary greatly, but an ovolo, as shown above, is very traditional.

a very large area, while at the same time counteracting any problems with wood contraction or expansion due to changes in humidity. A shiplap joint or tongueand-groove joint make using solid wood safe. And these joints leave an attractive

stra

tion

a yD

vid

back in the case. Those are the basics of case joinery. With this information, you’ll be able to choose the best joints for strong and attractive furniture.

el

Thi

b

Illu

Two joints for solid backs are the shiplap joint (top) and the tongue-and-groove joint. Both allow a solid wood back to move with seasonal humidity changes. The shiplap joint requires slightly less accuracy, but the tongue-and-groove joint offers a locking feature to counteract any warping.

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CHAPTER • 5

10 Tips for Tight Joints B Y P O P U L A R W O O D W O R K I N G S TA F F

You’ve cut all your pieces and are putting everything together when you first notice it – a gap. A dark void where there should be none. Don’t panic – it happens to the best of us. For whatever reason, there are instances when your joints just don’t fit perfectly and you have to decide what to do: Do you scrap all the time, energy, money and hard work you’ve put into the project and start over, or do you just let there be a little gap and move on? Well, we’re giving you a third option. We put our heads together and have come up with a list of the best tricks to help you tighten your joints. These tips should help you eliminate those unsightly, embarrassing gaps and point your joints in the right direction.

Compression Makes Dovetails Tight Hand-cut dovetails are some of the most challenging joints to fit perfectly. Many woodworkers will spend hundreds of dollars on router jigs or woodworking classes to get an airtight fit. If you decide to hand-cut your dovetails, there are a few ways to make sure you get it right. Because wood is – on a cellular level – similar to a bunch of soda straws glued together, you can compress it a little bit. Usually, compression is a bad thing, such as when you drop a hammer on your work and it dents. But a little bit of compression is good when dovetailing. Here’s how it works: Cut the first half of your joint as you usually would – I usually cut the tails first. Then use that 34

first half to knife in the second half of the joint – in this case, the pins. Next, when you saw your pin lines, don’t saw right up against the knife line you marked, as most books tell you. Instead, saw slightly wide. How wide? The whisker of a gnat would be a good place to start. Here’s how I do it: After I knife in my joint lines, I run a pencil over each knife line. Then I start my saw cut to leave the entire pencil line. Like all things pertaining to dovetails, this takes practice. Cut some sample joints to get a feel for it and use a magnifying glass to gauge your progress. Once you cut your pins, use a knife to ease the inside edges of your tails, which will be inside the joint. When you join your two pieces, the too-tight pins will compress the tails and the joint will be seamless. If you try to compress too much, one of your boards will split as the two boards are knocked together. This compression works especially

Pin

well with half-blind drawer joints where you are joining a secondary softwood for the sides (such as poplar) with a hardwood drawer front (such as oak), because the softwood compresses easily. But be careful: This trick doesn’t work when you are trying to join two pieces of dense exotic wood, which doesn’t compress much at all. — Christopher Schwarz

Fake Half-blinds for Dovetail Joints Half-blind dovetails are trickier to cut than through-dovetails, but they don’t have to be. I picked up this trick from dovetailing maestro Rob Cosman, who has two excellent videos on dovetails. Essentially, you first build a drawer with the easier through-dovetails and then glue a 1⁄ 4”-thick piece of veneer over the drawer front, making them look like half-blind dovetails. Usually with drawers you have 1⁄ 2”-

Waste

Pin cut wide

Wood compresses, and you can use that to make your dovetails tighter. Cutting your pins just slightly wide will force them to compress the tails.

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10 T I P S F O R T I G H T J O I N T S

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Veneered front Through-dovetails are easier to cut than half-blinds. To make life easier (and to stretch your stock of valuable wood) cut through-dovetails when joining your sides and drawer fronts. Then add 1⁄ 4"-thick veneer to the drawer front.

thick sides and a 3⁄ 4”-thick front. To do what we’re suggesting, make your drawer front with 1⁄ 2”-thick stock, too. Then join the sides to the front using throughdovetails. Then, using your band saw, resaw a piece of 1⁄ 4”-thick veneer from a piece of really nice figured wood. Make it a little larger than the finished size of your drawer front. Then glue that veneer to the drawer front, let the glue dry and trim it flush. This makes excellent half-blind dovetails and allows you to stretch your supply of nicely figured woods for your drawer fronts. — CS

Deeper Mortises Close Gaps It’s easy to get gaps when using a traditional mortise-and-tenon joint. Luckily, it’s also straightforward to get rid of them. If you make your mortises exactly as deep as your tenons are long, you’re asking for trouble. By doing this, you haven’t created a place for any excess glue to go, so it will be forced out of the joint. And if there is even a little bit of gunk at the bottom of your mortise, the joint won’t close tightly no matter what you do. To fix this, make your mortises 1⁄ 16” deeper than your tenons are long. This 36

trick will save you time because you don’t have to clean up the bottoms of your mortises as much, and it will prevent glue from squeezing out if you use too much in the joint. — CS

Paring Your Shoulders in a Mortise-and-tenon Joint Before you assemble your joints, you should always clamp them up without glue. That way, you can disassemble everything and fine-tune your joints if you find ugly gaps at this stage. But what if you can’t track down the problem? We’ve found that tuning up the shoulder of the joint will help you fix a variety of problems and make sure you don’t hurt the strength of the joint. First, clamp the tenon in your bench’s vise with the tenon pointing straight up. With a sharp chisel, pare away the inside of the shoulder without cutting the outside of the shoulder that shows. Pare away about 1⁄ 32” all the way around and then test the fit again. This should help you solve problems where your shoulders are angled a bit because of miscutting. It also helps out when the tenon’s mating surface isn’t perfectly square – it’s quite common to sand or plane that area so it’s bellied a bit. — CS

Use your workbench as part of your clamping setup when applying the veneer to the drawer. This setup helps spread pressure evenly across this large surface.

Tenon Mortise is 1/16" deeper than tenon is long Bottom of mortise

Making your mortise a little deeper prevents gaps at the shoulders.

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Tighten Mortise-and-tenon Joints with a Shoulder Plane A common problem with a mortise-andtenon joint is that it’s easy to make the joint too tight (so it won’t go together) or too loose (where it will fall apart). Even expertly machined joints have this problem because it’s tough to hold all your parts with exactly the same pressure as you cut them on your table saw or router table. A 1⁄ 128” difference can make or break this joint. Your tenons should slide into your mortises with hand pressure only. The fit should be firm but not forced. To get that every single time, I make all my tenons so they are slightly oversized. Usually I shoot for a tenon that fits a bit too tightly but would go together with a mallet. Then I get ready for a dry assembly and use my shoulder plane to tune up each joint. A good shoulder plane removes just a couple thousandths of an inch in a pass. This allows you to sneak up on a brilliant fit with only five or six swipes of the plane. It takes about 10 seconds per joint. Be sure to remove the same amount of material from each face cheek of the tenon by taking the same number of passes on each side of the tenon. Shoulder planes are available new from Lie-Nielsen, Clifton, Stanley and some other custom plane-makers, such as Shepherd Tool. You also can find them at flea markets or on the Internet. — CS Add Rabbets to Dado Joints Dados are deceivingly simple: You just cut a trench in your work that is exactly the same width as the thickness of its mating piece. The problem is getting the dado sized exactly right so you don’t have an ugly gap at the front of your joint or along the trench where the boards meet. Of course, to precisely size your dados you can use shims in your dado stack, buy undersized router bits or cut your joint in a couple of passes. Another option is to cut a rabbet on the mating piece. Using a rabbet requires an extra machinery setup, but it is worth

Pare the shoulder all around the tenon to help eliminate gaps in this joint. Be sure not to cut the edge of the shoulder, or you’ll make your gap worse instead of better.

Pare here … but not here

A couple of swipes on each cheek will tweak your tenons

To get your tenons fitting perfectly, learn to use a shoulder plane. This handy tool will fit your tenons in an extraordinarily controlled manner.

Dados are a pain to get sized just right. So don’t bother sizing the dado to the material. Cut the dado undersized and then cut a matching rabbet on its mate.

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Clearance hole Countersink

Pilot hole

A sharp and tuned smoothing plane can reduce your thickness in small increments, allowing you to sneak up on a seamless dado joint.

the trouble. Cut your dado so its width is 1⁄ 8” undersized. For example, if you were planning on a 3⁄ 4”-wide dado, make a 5⁄ 8”-wide dado instead. Then cut an 1⁄ 8”-deep rabbet on your mating piece that allows the two pieces to nest together. You can tweak the size of the rabbet to get the joint just right. — Steve Shanesy

Use a Hand Plane for Dados Another way to get perfect dados is with the help of a smoothing plane. If you can sharpen and set up a plane, this is for you. First, cut your dado so it is slightly undersized. I’ve found that the dado made by dado stacks is always a few thousandths of an inch less than the width you require. To cut a slightly undersized 3⁄ 4”-wide dado, I merely install all the chippers for a 3⁄ 4” dado. This has always worked, regardless of the brand of dado stack (Forrest, Freud and others). Then I just plane down the mating piece on both sides to sneak up on a perfect fit. Make sure you set your plane to make the finest shaving possible, and this should work for you. — CS 38

Stop Bridging Your Screws When Using Butt Joints There definitely are ways to improve your butt joints if you find gaps appearing. Screws and biscuits – used correctly – can make the joint tighter and more durable if you know how to use them. While dovetails and mortise-and-tenon joints are excellent options, we know that a lot of woodworkers use screws to simply pull butt joints tight. There’s nothing wrong with that, but using the correct screws and techniques will ensure that your joint actually is tight. Many woodworkers are using sheetmetal and drywall screws to assemble projects. These will work, but there’s a reason woodworking screws exist. The thread-free part of a wood screw shank (under the screw head) allows the threads to bite into the second wood piece, while the first piece (the one being attached) is able to pull tight against it. If there are threads over the entire length of the screw shank, the threads will bite into the wood in the attaching piece and will stop the first piece from seating tight when the screw head reaches the wood surface. This is something called “bridging,” and you’ll never get a tight joint.

The trick to a tight butt joint is drilling a proper clearance hole before you drive in a sheet-metal screw. The clearance hole prevents the threads from catching in the top piece.

Using a standard wood screw with a partially-threaded shank will solve this, or you can make sure the clearance hole in the attaching piece is large enough to keep the threads from catching in the wood. Either way, your joint will end up tight and solid. — David Thiel

Improve Butt Joints with Pocket-hole Screws, Biscuits We like pocket-hole screws to build utility cabinets and frames because no other joint is as fast or requires as little clamping. But there is one downside with pocket-hole screws when you are joining a shelf, top or bottom to a side. It can be quite difficult to hold the shelf in perfect position as you drive the screws home. If the piece shifts even the slightest bit, you’ll have a shelf that is cockeyed with an ugly, obvious gap on one side. To get around this, we combine biscuits and pocket-hole screws to get the best of both worlds. The extra time the biscuits take is minimal. First, cut your biscuit slots in your shelf and side piece. Then cut the pocket holes in the underside of the shelf. Put glue and biscuits in the biscuit

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slots and put the shelf in place. Then you can drive the pocket-hole screws home. Why do we like this method so much? Well, there are three reasons: • The biscuits hold the shelf in place as you drive the screws so it cannot shift and your case will be perfectly square. • The pocket-hole screws hold the shelf and side pieces together as the glue dries. This is especially helpful with the middle part of the shelf, which is difficult to clamp if you use only biscuits. The pocket-hole screws pull the pieces together across the shelf without a single clamp. • If you are a cheapskate, you can remove the screws once the glue is dry and reuse them. — CS

The Best Way to Clamp Miters in Casework Joining your cabinet’s sides and face frame with a miter is a classy way to dress up an ordinary box – and it is a signature of contemporary furniture design. But accomplishing this joint without an ugly gap somewhere along that miter is another story. Many people spend lots of money on corner clamps and clamping jigs. Or they construct convoluted cauls. My solution is tape. Yes, tape. I was shown this technique of cutting straight and clean joints and taping them together when I worked in a large production cabinet shop where time was money. I’ve used this technique on mitered joints that were 10’ long and it worked flawlessly. It also works great for gluing compound miters. To cut a clean miter using your table saw, set the blade to 45° and clamp an accessory fence to your saw’s rip fence. The accessory fence should be made using a softer wood, such as poplar or pine. A harder wood will ruin the sharp tip of your miter. Raise the blade while it is spinning until it kisses the accessory fence. Now you can cut your miters. The real trick to dead-on miters is how you glue them. As shown in the photos, tape the outside of the joint together, spread glue on the joint and then fold the parts to assemble things.

Biscuits keep the shelf aligned vertically and the pocket-hole screws help clamp the middle of the panel. Add some glue, cinch the screws down tight and you’re done – it’s that easy. And here’s the best part: No clamps required.

When taping your miters, lay the parts face up so the mitered edges are touching. Then tape the joint with clear packing tape.

Band clamps or more tape will hold the parts together as they dry. — Jim Stack

Next fold the assembly and use tape to hold it square until the glue sets.

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CHAPTER • 6

4 Joints for Box Making B Y D AV I D T H I E L A N D K A R A G E B H A R T

A wise man once said that all furniture building is box making. He’s still correct. A chest of drawers is simply a number of open-topped boxes slipped inside a larger box. If you can make a box, you can make nearly any kind of furniture designed for storage…we’ll save chairs and tables for another time. To help you along the way towards box (and furniture) making, we’ve come up with a couple of projects that actually are an excuse to talk about useful boxmaking joints. These two blanket chests use four basic and commonplace joints for corners: through-dovetails, rabbet joints, tongue-and-groove and biscuit joints.

blanket chest construction. When using power tools, it’s actually a little harder to create than half-blind dovetails, which are seen from only the side of the case. Dovetails are not only useful in case joinery, but are used extensively for drawers and smaller decorative boxes as well. When approaching dovetail joinery you should first decide whether you’re going to learn to cut the joint by hand, or invest in one of the many dovetail jigs that use a router to form the joint. We don’t want to make this an article debating the pros and cons of each method, but we should talk about both, briefly. Cutting dovetails by hand can be an immensely rewarding and liberat-

ing skill. It allows you to adjust the size, location and number of pins and tails used in the joint, something less easy when using a router jig. It also allows you to work with a minimal amount of noise and dust. One drawback is the amount of time necessary to feel comfortable in cutting into your carefully prepared lumber. One argument we’ve heard for handcut dovetails is the expense involved in purchasing a router and dovetail jig. Don’t fool yourself. Quality hand tools for hand-cut dovetails can quickly run up the credit-card balance. For this article we opted for a dovetail jig for our router. Making hand-cut dovetails is a full article in its own right,

Building a Traditional Chest Let’s start with the pine chest. We used through-dovetails on the front corners and a rabbet joint on the rear corners. Start by gluing- up the panels for the front, back and sides. They should finish out 1⁄ 8” or so longer than the cutting list calls for to allow room for the pins and tails to extend past the joint; they will later be sanded (or planed) flush to the case sides. Through-dovetails Let’s talk about the dovetail joint. Most woodworkers consider the dovetail joint a hallmark of quality craftsmanship. It truly is an amazingly strong method of joinery and adds a nice visual detail to a piece of furniture. We used a throughdovetail (meaning the joinery is visible from both sides of the corner) because it’s the more traditional dovetail joint for 40

We built blanket chests in traditional and contemporary styles to show off four box-making joints.

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Supplies: Traditional Chest Hardware from Lee Valley leevalley.com, 800-871-8158

After laying out the dovetail locations, set up the jig and router following the manufacturer’s directions. Cut the tails first with the dovetail bit, then use the opposite side of the jig with a straight router bit to cut the pins on the mating piece. With careful setup, a smooth fit is accomplished even if it’s your first set of dovetails.

2 • 10” lid supports 00T02.10 - $19.80 4 • 19⁄ 16” x 2” hinges 01H24.10 - $5.60 each 4 • 2”-dia. casters 00K26.50 - $8.20 each 1 • 1⁄ 4 lb. cut nails 91Z40.25 - $10.50 Dovetail jig from Keller & Co. kellerdovetail.com 800-995-2456 1 • Journeyman 22” dovetail system model 2200 - $239.00

and we’ll simply refer you to Ian Kirby’s “The Complete Dovetail” (Linden Publishing) for more in-depth instruction on that. When using a dovetail jig with a router, you’ll run into the aforementioned noise and dust, as well as a learning curve that is shorter than with hand-cut joints, but needs to be relearned when different thicknesses are used with the jig. Then there’s the expense. There are a variety of dovetail jigs available, but even the least expensive will cost more than $150 and that won’t include the necessary bits or the router to make the cuts. However, the convenience of quickly cutting a row of dovetails in less than an hour is a strong argument for spending the money. 42

THROUGH-DOVETAILS To cut the rabbet for the back corner joints on the pine chest, we used a two-step process on the table saw. First, cut the width of the rabbet, with the saw height set just shy of the rabbet width dimension (above). Next reset the fence and blade height to trim away the rabbet waste in an upright cut. Notice the waste piece will fall away from the blade, avoiding a dangerous trapped scrap piece.

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detail is to get the jig set up accurately. You’ll usually start by cutting the “tails” part of the joint first (though some halfblind jigs cut both simultaneously). First determine the location and layout for the dovetails. Follow the instructions for the jig to lay out and cut the tails. Once the tails are cut, adjusting the jig to make your pins fit is the important part. Though it requires tinkering to adjust the bit in the router and the jig itself, once it’s right you’ll be able to make as many perfect dovetails as you like. After checking the fit of your dovetails, the hard part is really over. The rear joint, the rabbet joint, is formed on the sides only by making two passes on the table saw. Here’s how to make it:

Traditional Blanket Chest NO.

❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏

1 1 2 1 1 2 2 2

ITEM

Front Back Sides Top Bottom Base mouldings Side mouldings Battens

DIMENSIONS (INCHES) T W L

MATERIAL

3⁄

4

3⁄

4

3⁄

4

7⁄

8

Pine Pine Pine Pine Pine Pine Pine Pine

5⁄

8

3⁄

4

3⁄

4

3⁄

4

357⁄ 8 347⁄ 8 181⁄ 2 371⁄ 2 181⁄ 2 373 ⁄ 8 20 15

19 19 19 191⁄ 8 357⁄ 8 3 3 21⁄ 2

There are a number of jigs capable of making quality dovetail joints. For our particular chest we chose a Keller dovetail jig because it offered the best width capacity for making our dovetails at a reasonable price. To make our through-dovetail joints (the two front joints in the pine chest), we first prepared the wood, making the panels the appropriate thickness (3⁄ 4”), width (in this case the width of the wood is the height of the chest to allow

for seasonal wood movement because of changes in moisture content) and length. Dovetails should always be cut on the end-grain ends of a board to provide the strongest joint. Cut your front, back and sides a 1⁄ 16” to 1⁄ 8” longer to allow for sanding or planing the joint flush to the sides. With the wood panels prepared, head to the dovetail jig with a piece of scrap left over from sizing the panels. No matter what jig you’re using, the critical

34 7/8"

Construction Notes:

A C

Random-width shiplapped boards screwed to bottom of case Through-dovetail corner joint

B C

A

18 1/2"

Rabbet Joint For the rear joint on the pine chest we opted for a very simple joint, but one still reasonably strong and appropriate for the case. The rabbet joint requires cutting a rabbet in the back edge of both

3/4"w. x 1/4"d. rabbet joint w/ cut nails 1/4" x 1/4" chamfer, typical

D E F

B

Hinges mortised into case Lid battens

Plan - lid removed

RABBET JOINT

19 1/8"

37 1/2" 35 7/8"

F

D

15"

7/8"

F

B

C

B

E

19"

22 1/4" 3/4"

A

6"

1"

1/2"

1"

D

3/4"

3" 18 1/2"

37 3/8" ELEVATION - SECTION

20" PROFILE - SECTION

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The rear rabbet joint is a better joint than a butt joint for stability, but some glue and a few nails make it an even better joint. To make the nails more attractive, we used antique-looking cut nails.

sides. The width of the rabbet should equal the thickness of the stock. The depth of the rabbet should be one-third to two-thirds the thickness of the stock. The back then nests into the rabbets in the sides and is nailed in place through the sides. We used 1⁄ 4” x 3⁄ 4” rabbets, cut in two passes on the table saw (see photo at left). While this isn’t the strongest joint for casework, the nails provide excellent strength, while the rabbet joint provides stability and squareness. It’s also a quick and simple joint to prepare that will provide adequate strength for most boxes. With the rabbet joint complete, it’s almost a box. You can go ahead and glue the four sides together. Glue should be applied to all the “walls” of the dovetails in an even coat. When clamping the dovetail joint, use cauls as long as the box is high and placed directly behind the pins and tails. This allows the pins to extend beyond the tails in the joint, forming a tight joint. Put glue on the two surfaces of the rabbets and slip the back in place. Add clamps and check for square, measuring across the corners of the box. To add some extra strength and a nice look to the piece, Kara nailed the rabbet joints together with square-cut 44

nails. Pre-drill holes for the nails to keep the ends of the sides from splitting. Once the glue on the joints has dried, sand or plane the parts of the pins and tails extending beyond the case surfaces flush, and the joint is complete. With the box assembled, it’s time to add a bottom. Because we were already familiar with cutting rabbets on the

saw, we opted for a shiplapped bottom. By cutting rabbets half the thickness of the bottom pieces on alternating long edges of each bottom piece, you’ll create a strong and gap-free bottom. Cut the bottom pieces to fit the depth of the chest, front-to-back. Start with one bottom board with only one side rabbetcut. Attach it to the bottom of the box, screwing only through the center of the board, one screw at each end. Add the boards along the width of the chest, again, using one screw on each end of each board. When you reach the other end of the box, cut the width of the last board to fit the box. To hide the edges of the bottom boards and dress up the blanket chest, cut the base mouldings to size. We added a 1⁄ 4” chamfer to the top edges of the base mouldings to soften the look, then mitered the corners and glued and nailed the base in place. The dimensions given in the diagrams are designed to allow the specified casters to extend below the base by 3⁄ 4”, leaving ample room for movement on carpet. Next, cut the top to size, allowing 13⁄ 5 16” overhang on each side and ⁄ 8” to the front. Screw two battens to the underside of the top, using elongated holes. The battens help keep the top

The bottom pieces are shiplapped (with opposing rabbet cuts on the long edges) except for the two outer boards that are left square cut. Screw the pieces in place with a single screw on each end, pre-drilled and centered on the board. Use dimes (as shown here) to evenly space the boards – this will allow for wood movement.

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Supplies: Plywood Blanket Chest Hardware from Lee Valley leevalley.com 800-871-8158 2 • soft-down flap stays 00T02.10 - $19.80 each 4 • 2”-dia. casters 00K26.50 - $7.40 (pkg. of 4) 1” x 3’ nickel piano hinge from local hardware store

flat, and the elongated holes allow the wood to move with seasonal humidity changes. Four butt hinges attach the top to the case, and two lid supports hold the lid open. After some sanding, we added a few coats of orange shellac for a simple finish.

Miter the base moulding pieces to fit, then cut away the front and rear pieces in the center to lighten the look of the piece. When ready, all four pieces are glued in place around the chest bottom. A brad nail or two, or a triangular shaped support block behind the mitered corners isn’t a bad idea to add some additional support.

Building the Plywood Chest Building a chest out of plywood simplifies some things and complicates others. It’s not necessary to worry about seasonal wood movement, but you do have to hide the plywood edges to make things look nice. While we used two different corner joints for the plywood chest shown (tongue-and-groove and biscuit) it would probably make sense for you to choose one or the other joint and use it for all four corners. Whichever joint you’re using, start by cutting the four corner pieces to size. We chose quartersawn sycamore.

manufactured biscuit is slid into the matching pockets, forming a loose tongue. This is a fast, reasonably foolproof and forgiving method of joining the panels to the posts. While not as strong as a tongue-and-groove joint, it’s adequate for many applications. We liked the look of the 1⁄ 4” recess of the panels, so it made it necessary for us to readjust the height adjustment on the biscuit joiner when cutting the panels versus the blocks. Cut all the biscuit slots (we used three #20 biscuits per joint).

Biscuit Joints If you’re using biscuit joinery, the blocks are ready for your cuts. Lay out the biscuit locations on the blocks and cherry plywood panels. The blocks are held flush to the top of the panels, but they’ll stop short of the bottom edge of the panels. That’s OK. The biscuit joint is a variation on the tongue-and-groove joint. Essentially what’s changed is rather than use a table saw to first cut a tongue and then cut a groove, a biscuit joiner uses the same blade and tool to cut matching “slots” or pockets. Then a flat, football-shaped

Tongue-and-groove The tongue-and-groove that we’ve used on the plywood chest is the simplest to cut, and it offers a side benefit as well. A tongue-and-groove is often cut so that the protruding “tongue” part on the panel is centered on the thickness of the piece and the tongue is one-third the thickness of the piece. This is fine, but it requires cutting from both sides of the panel. We chose to form our tongue by cutting a rabbet on one side of the panel, leaving the tongue flush with one face of the panel. In our opinion, this leaves a stronger tongue. When the groove is cut

BISCUIT JOINT

TONGUE-ANDGROOVE JOINT

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With the tongues cut (in this case using the same rabbeting cut as used in the other chest) a dry-fit is again in order. Because the tongue is positioned to the outside of the cabinet, there’s no concern of an inaccurate shoulder cut showing up on the outside.

To cut the grooves for the tongue-andgroove joints, make repeat cuts on the table saw, starting with the “outside” edge to set the 1⁄ 4" offset. Cut both sides, then reset the fence, working your way in until you have the appropriate tongue thickness.

46

Biscuit joinery is fast, simple and almost foolproof. After marking the six locations per corner, it’s a simple matter to cut the slots in the center of the plywood edges, then reset the fence to add 1⁄ 4" in height (to allow for the 1⁄ 4" recess on the panels) and cut the slots in the corner pieces.

With the biscuit slots cut, a dry fit is always a good idea. It also helps you to visualize how and where the clamps need to be oriented to successfully glue up the case.

in the opposite piece (or in our case the corner post) it is cut off-center to locate the panel where needed. Again, for our needs, we used solid corner posts to both hide the plywood edges and form a 1⁄ 4” offset between the panels and posts. With the offset tongue, the point where the tongue enters the groove in the posts helps to hide any part of the tongues’ rabbet from the outside of the case. To form the tongue-and-groove joinery, use the detail drawings to locate the grooves in the posts, then use the table saw to cut the grooves. To form the tongues on the plywood, cut rabbets on the panels using the same technique shown in the traditional chest. Before gluing up the corners, head to the table saw and cut 3⁄ 4” x 3⁄ 8” dados, 1⁄ 2” up from the bottom of each panel. These dados will house the plywood bottom. Now cut the bottom to size to fit into the dados, then glue the chest together, capturing the bottom in place. You’ll notice the corner blocks stop even with the top surface of the bottom. The next step is to hide the top edges of the plywood panels. We cut “U”-shaped caps to slip over the plywood edges. To let the caps meet at the corners, we cut away part of the sides of the caps, then mitered the corners.

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1 1/4"

1/4"

A

32 3/8" panel

3/8" 1/4"

5/8"

3/8"

1 1/4"

1 7/8" 1 /4"

1/4"

B

A BISCUITED CORNER POST

16 3/8" panel

1 1/4"

TONGUE-AND-GROOVE CORNER POST

33 1/8" panel

B

PLAN - LID REMOVED 3/8"

lid moulding

cap moulding

1/4" r. 3/4"

1/2"

36" panel 3"

piano hinge

C

LID ELEVATION - SECTION

D

34 7/8" cap moulding 1/2"

HINGE DETAIL

7/8"

1/4" r.

1/4" r.

3/4"

1/2" 3/4"

1 1/4"

3/4"

1 1/2"

17 3/4" corner post

1 1/4"

11/4"

E

3/8"

3/8"

F

LID MOULDING

Follow the photos to form the top corners. Then glue and nail the caps in place. We added a 1⁄ 4” roundover bit in a router on the top edge of the base moulding to soften the look of this chest. The base on the plywood chest is cut and attached by nailing through the 1⁄ 2” of exposed panel below. Next, glue and nail on some accent strips on the front and back of the chest to add a nice detail. The top on the plywood chest is complicated by the need to hide the unsightly plywood edges. We took this opportunity to allow the top to lip over the case, adding another extra detail. Follow the diagrams to cut the lid moulding to size

11/4"

17" accent strip

19" panel

3"

1/2" 1/4"

F

11/4"

BASE MOULDING

1 1/4" 1/4"

E

36 3/4" lid moulding

1 1/2"

D

357/8" base moulding

1/4"

ELEVATION - SECTION CAP MOULDING

Plywood Blanket Chest NO.

❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏ ❏

2 2 1 1 4 2 2 2 2 2 2 2

ITEM

Front & back Sides Bottom Top Corner posts Cap mouldings Cap mouldings Lid mouldings Lid mouldings Base mouldings Side mouldings Accent strips

DIMENSIONS (INCHES) T W L

3⁄

4

3⁄

4

3⁄

4

3⁄

4

11 ⁄ 4 11 ⁄ 4 11 ⁄ 4 11 ⁄ 4 11 ⁄ 4 3⁄

4

3⁄

4

1⁄

4

1⁄

33 8* 163 ⁄ 8** 171 ⁄ 4 197⁄ 8 11 ⁄ 4 11 ⁄ 4 11 ⁄ 4 11 ⁄ 2 11 ⁄ 2 3 3 11 ⁄ 4

19 19 335 ⁄ 8 36 173⁄ 4 347⁄ 8 185 ⁄ 8 363 ⁄ 4 20 5 ⁄ 8 357⁄ 8 195 ⁄ 8 17

MATERIAL

Plywood Plywood Plywood Plywood Hardwood Hardwood Hardwood Hardwood Hardwood Hardwood Hardwood Hardwood

*For biscuit joint, change to 323⁄ 8”; ** If using biscuit joint, change to 16”.

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and shape, then miter, glue and nail the moulding to the plywood top piece. Once again, the casters are attached to extend below the base. We used a continuous (or piano) hinge on this case, and had to attach it in an unusual fashion to allow the top to open smoothly. Follow the diagrams to determine the attachment location. We also used a different type of lid stop that has adjustable closing tension to keep the lid from slamming closed. Follow the directions from the manufacturer to attach the lid stops.

To miter the caps and allow them to successfully slip over the corner blocks, the mouldings should first be mitered to fit, then the corner block locations marked. Then it’s simply some careful band-saw work. First define the cutout height (above), then use a miter gauge on the band saw to cut away the waste block (upper right). It’s wise to cut short of the line and refine the fit a little at a time. This can be done with a flat file also, if your band saw isn’t leaving a very clean cut line.

Attach the base moulding by nailing it to the case from the inside as shown. I used spring clamps to hold the base moulding while nailing it in place.

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CHAPTER • 7

Adding Accuracy When you are using power tools for cutting parts and joinery, accuracy has less to do with laying out individual workpieces and more to do with mastering setups. I have a simple routine. Whether I’m cutting parts or joints for a project, the routine helps me achieve good results with a minimum of fuss: • Set the cutter and the guide device. • Make a test cut and measure. • Tweak the setup. Do the initial setup carefully, keeping a few guidelines in mind that will simplify the inevitable tweaks. But don’t get nuts about it. It’s easy to waste time trying to get a perfect setup. For the initial setup, close is enough. The test cut is your best means of evaluating the setup and making effective adjustments. Practice does make you better at this. Your “eye” improves, and your hands become more deft. Once you understand the routine, the whole process becomes second nature.

OK, What are the Guidelines? • Start BIG. If you are cutting parts, for example, you want your test cut to leave the part oversized so you don’t waste material. Once it is too short or too narrow, you can’t go back. You’ve got to start over. • Account for the “backlash” that’s inherent in adjusters. Backlash is excessive play between adjacent moveable parts in a mechanism. Many of us are familiar with the looseness in a table saw’s blade-height adjustment. Crank the blade up, then lower it. As you

A reference block and shims allow controlled tweaks to both fences and stops. The reference block can be almost any scrap. Suitable shims range from playing cards and scraps of plastic laminate to precision-thickness gauge blocks (the brass bars in the photo) and feeler gauges.

reverse the direction, there are several degrees of free movement before you feel the resistance of the gears meshing. That slack is the backlash and it is a problem. The way to deal with it is to stage the setup so the adjuster is moving against the pressure that results when the tool is turned on and the cut begins. If you neglect to lock the crank on the table saw, the blade is going to slowly drift down. Make the initial setting and your tweaks by elevating the blade. Begin the setup with the cutter below the saw’s table. Raise it for the initial test cut, but deliberately leave it low. You want to creep up on the setting. Remember that backlash isn’t a problem only on the table saw. It affects the adjustments on routers, router lifts, edge

guides, radial-arm saws, planers and many other tools. • Use stops wherever you can. Stops do more than arrest movement. They establish limits. When you use a stop for an operation, you have a good means to ensure consistent, accurate results. You also have a good base from which to tweak your setup.

Initial Setup Initial setup can be done with a rule. Here are some examples: • Almost every table saw’s rip fence has a scale giving you a reading on the distance from the fence to the blade. But you can’t use it for every setup. If you are setting up for the shoulder cut of a rabbet, you need to include the blade in the A D D I N G AC C U R ACY

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Photos by the author

B Y B I L L H Y LT O N

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measurement. The scale, though, doesn’t give you that. • For crosscuts, whether on the table saw or a power miter saw, use a rule butted against a tooth (not the plate) of the blade to set a stop (see photo at right). A tape measure is usually on my belt, right at hand for all sorts of measuring. But for this task, I use a steel rule, whether a 6” pocket rule, a yardstick or something in between. • Set a router table fence with a square. Hold the head against the fence with the rule extending just above the bit. Measure either to the cutting edges or to the axis of the bit. When possible, eschew measurement entirely and use a setup gauge. The obvious example here is using an existing part to set a cutter height, fence position or stop so you can make a duplicate. Machinists use a multipurpose gauge system for accurate setups. A steel onetwo-three block is precisely 1” thick, 2” wide and 3” long. You can make your own using a stable hardwood. Setup gauges are slivers of steel, aluminum or brass in precise thicknesses. Want to rip a 3”-wide stile? Butt the end of the one-two-three block against a tooth of the saw blade, then slide the rip fence against the other end. Want the stile 25⁄16” wide? Turn the block so its 2” side is against the blade and add a 1⁄4”thick gauge and a 1⁄16”-thick gauge. When you are making a two-part joint (tongue-and-groove, cope-andstick and half-lap are prime examples), use the first half of the joint to reset the cutter height or fence position for cutting the mating part

The Test Cut All this gets you close, but where accuracy is essential, you must check things with a test cut. Follow-up tweaks are usually needed. Don’t make the test cut in just any old scrap from the offcuts bin. If you are simply checking the width of a rip cut or the length of a crosscut, by all means use scrap. But think it through. If you’re testing a joinery cut, the actual girth of the working stock is of critical importance. Yes, using a real workpiece can be risky. 50

You can set the bit height using a rule but sometimes using a workpiece is more accurate. Here a mortising bit is being set to cut tenons. Whether you use a rule or a mortised workpiece, leave the bit just a bit low. Cut a test tenon and fit it to the mortise. Fine-tune the bit height based on the fit.

Use a steel rule to set a stop for crosscuts on the table saw. Butt the rule against a tooth (not the plate), align the block over the target graduation, and clamp the block to the fence.

To accurately set a router table fence for a precision test cut, use a machinist’s small adjustable square. Rotate the bit to align the cutting edges, then get the rule as close as possible to the appropriate edge.

Gauge blocks can be used to set a fence in relation to a cutter. Here the gauge is a scrap of 1 ⁄ 4" hardboard and the tool is a mortiser. Just hold the gauge against the fence and slide the fence into contact with the chisel.

Sawing a rabbet in two passes? Forget the fence’s scale when setting up the shoulder cut; you have to measure from the outside of the blade. Use a scrap of the stock that will be housed in the rabbet. Your touch will tell you when the scrap’s face is flush with the blade’s cutting tips.

When readjusting the blade for the bottom cut, a shoulder-cut sample is going to be the most accurate gauge. Raise the blade so its teeth just skim the shoulder; you don’t want a ridge of waste where the shoulder meets the bottom.

As you plan a project, you can foresee this situation, so make it a point at the outset to prepare extra pieces for testing setups. Evaluate the resulting cut. If it is a joint, see if the mating parts fit together

properly. If it is a part, see if it fits the assembly. If measurement is required, use a precision tool. Your trusty tape measure isn’t it. In many instances, dial (or digital) calipers are. With a standard 6” caliper, you can

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measure inside and outside dimensions, as well as depths. You can measure the thickness of a piece of plywood or a scrap of veneer, the width of a dado, the depth of a rabbet. You can make the measurements quickly, and with unmatched accuracy. Machinists use dial calipers to measure in thousandths. Fractional dial calipers do the conversion from decimals to more familiar fractions for you. If you can measure a part or a cut with the calipers, and you have the means to move the cutter, fence, or stop a precise distance, you can tweak setups efficiently.

Tweaking Your Setup In many woodshops, a gentle bump with a fist or the heel of a hand on a fence is what passes for a tweak to a setup. If that works for you, fine. I do it too sometimes, but the results are seldom really satisfactory. Your aim is precision. Having done the initial setup so it would be tweak-able, and having made and precisely measured your test cut, you should follow through with the same mind-set. At this point, the question is: What’s the difference between the cut you want and the cut you have? Is the cut you have too deep or too shallow? Too wide or too narrow? Is the piece too long or too short? The answers tell you how much and in what direction to adjust your setup. Most table saw rip fences (and some commercial router table fences) have a scale to aid in positioning. The scale works for adjustments of 1⁄32” but precise movements smaller than that are iffy. One helpful trick for fence adjustments is to scribe a pencil line on the tabletop along the fence during the initial setup. This line gives you a way of assessing the movement. If you move the fence away from the line, you may be able to actually measure the gap. The risk in moving the fence toward the pencil line is that once the line disappears under the fence, you have no way of determining how far past the line the fence has moved. On a router table, you can often put geometry to work for you. Did you

When you must machine both halves of a joint, use the first part to set up for cutting the mate. Set up for cutting a tongue by aligning the slot cutter against a sample of the grooved stock. “Prove” your setup with a sample cut before cutting all the work.

Use dial calipers to measure a test cut. The tool’s jaws accurately capture the measurement, and it displays the dimension in increments as fine as one thousandth inch (.001"). Fractional dial calipers eliminate the need to convert from decimals.

know that if you move only one end of the fence, the distance you move it at the edge of the table is halved at the middle of the table? That means swinging one end of the fence 1⁄16” moves it only 1⁄32” at the bit.

be moved, you can use scraps of MDF as shims at one extreme and feeler gauges at the other extreme. The machinist’s setup gauges I mentioned earlier are perfect for this. By combining the various thicknesses, you can range from 1⁄ 16” through a full inch by 16ths. For smaller increments, I use feeler gauges, playing or business cards, alone or in combination with other shims. I use this block-and-shim approach primarily for adjusting the fences on my router tables, but it works equally well with a few jigs and fixtures I use with portable routers, and with the table saw’s rip fence. A variation is a block with a machine screw threaded through it. Clamp the block with the screw against the fence. Turning the screw one way pushes the unlocked fence toward the cutter, while backing the screw away from the fence allows it to be pushed back away from the cutter. Using a commonplace 3⁄8”-16 bolt or screw in your block provides a measured adjustment – 1⁄16” per full turn. I use a cap screw and turn it with an Allen wrench. You can make adjustments of 1⁄ 128” pretty easily. It’s 1⁄ 8 of a turn – just 45°.

The Reference-block-and-shim System Let’s say you want to move the fence 1⁄ 16” closer to the cutter. First place a block of wood against the back of the fence and clamp the block to the table. Now unlock the fence and move it far enough to drop a 1⁄ 16”-thick shim between it and the block. Slide the fence back, pinching the shim between it and the block. Re-lock the fence. If you need to move the fence away from the cutter, the tweak is just as simple. First pinch the shim between fence and block as you first position and clamp the block to the table. Then unlock the fence, remove the shim, shift the fence directly against the block and re-lock the fence. Depending on how far the fence must

Use a reference block and shims to move a router-table fence closer to the bit. Unlock the fence and slip your shims between the fence and reference block. Push the fence tight against the shims and the block and re-lock it. The movement at the bit will be half the thickness of the shims.

A D D I N G AC C U R ACY

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CHAPTER • 8

Mastering Through Mortise & Tenon BY FRANK KLAUSZ

In furniture making, while carcases and drawers are dovetailed together, tables and chairs have mortise-and-tenon joinery. In this article, I make a through mortise and tenon three different ways. First by hand, second with a hollowchisel mortiser and table saw, and third with a plunge router and band saw. In 1991, I had a very nice commission to make about a dozen pieces of Egyptian furniture for the Newark Museum in New Jersey. I had the opportunity to see the real, original ancient pieces and make measured drawings to do the work. The pieces I had to make are more simple ones which are less well known than the spectacular furniture from the tomb of King Tutankhamun. This stool at left is a copy of a New Kingdom craftsman stool. I made it 2” higher than the original. The Egyptians were squatting before they had stools and the low height of the stool was designed for sitting in this squatting position. All the stools have through mortiseand-tenon joints with the seat rails meeting above and below one another at the legs. Some of the stretchers are the same way. Some tenons are pegged and some are wedged; the ancient stools

Educated in the Hungarian trade-school system, Frank is a master cabinetmaker, author and owner of Frank’s Cabinet Shop in Pluckemin, New Jersey, which specializes in fine furniture reproductions and custom architectural fixtures. He also teaches woodworking. For more information visit frankklausz.com.

52

were held together by the webbing. I glued mine. The seats on the stools are also different. Some have a solid, curved seat carved from four planks, others are woven with reed and rush fibers, while still others have holes on the inner edge of the seat rails and are woven with simple double-braided rush webbing that looks like caning. The ends of all the strands are carefully knotted below the holes and hidden from sight. I made a bed in this manner for the museum.

Chop and Saw by Hand To do mortise-and-tenon joints by hand, you have to do a lot of marking. After stock preparation, you mark the cor-

ner of the legs with a scribble to indicate the outside corners. With a square and a sharp pencil, mark the thickness of the seat rail 1⁄ 2” below the top of the leg. Flip the leg and mark first under the lower rail’s location. For a through mortise and tenon, transfer these lines to the outside of the legs. Make sure you end up with pairs. Mark the location of the stretchers at the bottom in the same way. To locate the tenon shoulder from the rail ends, mark the seat rails and stretchers, using the width of your leg as your guide, plus 1⁄4” (which is how much the tenon sticks out from the leg). Measure the width of your stool and mark your other shoulder. Set the two cutters of your mortising YYUFOPO

UISPVHINPSUJTF

EGYPTIAN STOOL – EXPLODED VIEW

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gauge to the thickness of the chisel, as shown at left, then move your fence so the cutters are centered in the stretchers and mark them. Do the same with the seat rails. Reset your marking gauge and mark the legs. Make sure you are in the middle. Clamp the leg to your bench and start chopping. Stay away from the pencil line and take 1⁄8” chips. Keep going deeper and pry out your chips. When you are halfway through, do the final cut on the line. Turn it over and do the same from the other side. You can clean your hole with a rasp. For the tenon, I use a bowsaw, as seen at left. I clamp the pieces in my bench and cut them making sure I am on the line. If you do not have a bowsaw, use your tenoning saw. I cut on the waste side, leaving the tenon snug. To cut the shoulders I use a dovetail saw, as seen in the center photo below. I bevel all four sides of the ends of the tenons with a chisel. Try the fit and adjust with the rasp and chisel until it is just right. It should be tight along the width, not from end to end.

Mortiser and Table Saw To mortise with a hollow-chisel mortiser, mark your legs the same way. You do not need a marking gauge; the machine’s fence will set the chisel to the middle, as shown below right on the facing page. The hollow chisel should be set so that the drill bit has a credit-card thickness gap at the bottom between the chisel and the end of the drill bit to leave room for the chips to go up and not run hot. Mortise halfway, flip it and mortise from the other side. This way you have clean openings. To tenon on the table saw, I use my tenoning jig, which fits on the table saw fence. Mark a scrap with small lines for the width of the tenon. Set up the saw by trial and error until it is right before you cut the real pieces. The cam clamp holds the piece in the jig for a very safe and repeatable cut. To cut the shoulders, set up your blade height and use a block of wood on the fence for extension to leave more gap to clear the scrap (see photo next page). This way your saw will not jam. Use the miter gauge with a block of 54

Setting your marking gauge to the tool lets you use the width of your chisel to determine the width of the mortise.

Clamp the leg securely to your bench and chop halfway through. Then flip the leg over and complete the mortise from the other side.

I use a traditional European bowsaw to cut the tenons by hand.

wood and a piece of sticky-back sandpaper so that your wood does not slide.

Plunge Router and Band Saw To mortise with a plunge router, you have to make a jig like the one in the drawing at right, and in the photo on the next page. Mine holds a 3” x 3” piece so a table leg will fit into it. Smaller pieces

get shimmed and wedged for safe work. Use a two-flute carbide up-spiral bit. On the router fence, I use a block of wood that slides back and forth in the jig safely. Take small cuts of about 1⁄ 4” down each time. Cut halfway, flip and cut from the other side. I square up the corners with a chisel. If I am making doors, I round off the tenons and wedge them, as

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An alternative to the bowsaw is a tenon saw, filed for ripping.

A dovetail saw, filed for crosscutting, is used to make the shoulder cuts.

The hollow-chisel mortiser will save some time in marking because the fence on the machine will center the cut.







TENONING JIG

MORTISING JIG ELEVATION









P 

MORTISING JIG WEDGE (MAKE 2)

CAM LAYOUT

MORTISING JIG

MASTERING THROUGH MORTISE & TENON

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YDIBNGFS



RAIL ELEVATION









UIJDL





 YYUFOPO 

YUISPVHINPSUJTF





Egyptian Stool



NO.



4 8

ITEM

DIMENSIONS (INCHES) T W L

MATERIAL

Legs

17⁄8

17⁄8

14

Cherry

Rails

7⁄ 8

11 ⁄4

19

Cherry

 TRVBSF LEG ELEVATION

seen in the photo at the bottom left of the page. It’s much quicker. To cut tenons on a band saw, set up the band saw fence and mark a scrap of wood, as shown at bottom right. As with the table saw, cut it by trial and error and once the scrap is right, cut the real pieces. Cut the shoulders by hand with a dovetail saw. Remember that all of these methods can be mixed. Use the one you like best. I antiqued the stool by rounding off the corners unevenly with a chisel, rasp, broken brick, etc. I finished it with shellac and brown wax. From a cow hide, I cut 1” strips for weaving the seat, which I learned from Brian Boggs’ DVD on hickory bark, sold by Lie-Nielsen Toolworks (lie-nielsen.com or 800-3272520).

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The stop clamped against the table saw fence registers the shoulder cut, and keeps the work from jamming between the fence and the blade. Note: There are no shoulders on the edges.

With this jig and an up-spiral bit, a plunge router will make clean mortises quickly.

The router leaves mortises with rounded ends. Square them off with a chisel, or round the ends of the tenons to match.

The fence on the band saw lets you make long straight cuts on the cheeks of the tenons.

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CHAPTER • 9

Mortise & Tenon Basics BY CHRISTOPHER SCHWARTZ

A lot of woodworkers spend a lot of time, effort and money to avoid making mortise-and-tenon joints. Biscuits, dowels, commercial loose-tenon jigs and expensive router bits are just a few of the “work-arounds” developed this century so you don’t have to learn to make a mortise and its perfectly matched tenon. But once you learn how straightforward and simple this joint can be, you will use it in every project. Why? Well, it is remarkably strong. A few years ago we decided to pit this venerable and traditional joint against the high-tech super-simple biscuit. So we built two cubes, one using biscuits and one with mortises and tenons. Then we dropped a 50-pound anvil on each cube. The results were eye-opening. Both cubes were destroyed. The biscuit cube exploded on impact. Some of the biscuits held on tightly to the wood, but they pulled away chunks from the mating piece as the joint failed. The second cube survived the first hit with the anvil – the joints held together even though the wood split at the points of impact. A second hit with the anvil ruined the cube entirely, though most of the tenons stuck tenaciously to their mortises. The lesson here is that biscuits are indeed tough, but when they fail, they fail catastrophically. The mortise-andtenon joints fail, too, but they take their time, becoming loose at first rather than an immediate pile of splinters. So when you’re building for future generations and you know how to make this stout joint with minimal fuss, you MORTISE & TENON BASICS

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Lever

TIPS & TRICKS The Anvil Test

Holddown

1

2

The anvil is about to hit the cube made using #20 biscuits.

The cube made out of biscuits is destroyed on impact.

Tape squares table Table

Hollow-chisel mortisers excel at boring square holes. Here you can see the holddown (which is usually inadequate with other machines), the table (which must be squared to the chisel before use) and the lever (which makes the machine plow through almost any job).

3

4

The mortise-and-tenon cube held together after the first hit.

The mortise-and-tenon cube collapsed after the second hit.

won’t say “Why bother?” You’ll say “Why not?”

this technique, these tools will become the foundation for much of your jointmaking.

Choosing the Right Tools There are so many ways to cut this joint that one big obstacle to mastering it is choosing a technique. I’ve tried many ways to cut this joint – backsaws, commercial table-saw tenon jigs and even the sweet $860 Leigh Frame Mortise and Tenon Jig. Each technique or jig has advantages in economy, speed or accuracy. The technique I’m outlining here is the one I keep coming back to year after year. It uses three tools: a hollow-chisel mortiser for the mortises, a dado stack to cut the tenons and a shoulder plane to fine-tune your joints. Yes, this is a little bit of an investment, but once you start using 58

Hollow-chisel mortisers

These machines are nothing new, but the benchtop ones are now cheaper, more powerful and more accurate than ever. For about $240, you’ll get a good machine. Essentially, a mortiser is a marriage between a drill press and an arbor press that’s designed for metalworking. The drill press part has a spinning chuck that holds an auger bit that chews up the waste wood. The auger bit is encased in a hollow four-sided chisel that cleans up the walls of your mortise, making the auger’s round hole a square one. The arbor press part of the machine

is the gear-and-lever system that pushes the tooling into your wood. This mechanism gives you an enormous mechanical advantage compared to outfitting your drill press with a mortising attachment – an accessory I don’t recommend for all but the most occasional mortising jobs. Shopping for the proper mortiser is tough. I don’t consider all the machines equal. Some are weak and stall in difficult woods such as oak, ash and maple. Many have problems holding your work down against the machine’s table. In a review of the machines on the market, we preferred the fast machines (3,450 rpm) instead of the 1,750-rpm slow machines. The fast machines were almost impossible to stall. However, the marketplace seems to prefer the slow machines. Dado stack

A good dado stack will serve you in many ways, but I use mine mostly for cutting tenons and rabbets. When it comes to choosing one, buy a set with 8” blades instead of 6” blades, unless you own a

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A shoulder plane tweaks tenons to fit perfectly. Avoid the modern Stanley shoulder planes (not shown). Spending a few dollars more will get you a much better tool.

benchtop table saw. Stay away from the bargain sets that cost $50 or less – I haven’t found them to be very sharp and the teeth aren’t well-ground. The expensive sets ($200 and more) are nice, but they’re probably more than you need unless you are making your living at woodworking. Shoulder plane

No matter how accurately you set up

your machines to cut mortises and tenons, some will need a little tuning up before assembly. And nothing trims a tenon as well as a shoulder plane. These hand tools really are secret weapons when it comes to joints that fit together firmly and are airtight. Why is that? Well, shoulder planes are designed to take a controlled shaving that can be as thin as .001”. I can tweak a tenon to a perfect fit with just a few

Mortise Edge cheek Edge shoulder should be at least 3/8" to avoid blowing out the mortise

Face shoulder

Rail

Stile

Face cheek Tenon thickness should be one-half of your stock's thickness

passes. Trying to tweak a tenon with a chisel or sandpaper is more difficult. You are more likely to gouge or round over the surface of your tenon and compromise its mechanical strength. Buying a shoulder plane gets easier every year because there are now many quality tools on the market. Unless you build only small projects, you are going to want a plane that is at least 1” wide. Most casework tenons are 1” long, so a 1”-wide plane is perfect for trimming up the face cheeks and shoulders of the tenon. My advice is to stay away from the newly made Stanley shoulder planes. I’ve had some sloppily made Stanleys go though my hands (vintage Stanley shoulder planes can be good, however). Lie-Nielsen makes two shouldertrimming planes worth saving your money for. The #073 is a tool of great mass and presence and does the job admirably – it’s a $225 investment. LieNielsen also makes a rabbeting block plane that can be easily used as a shoulder plane; it costs $150. It’s the tool I recommend to most people because it does double-duty as a low-angle block plane. Veritas, the tool line made by Lee Valley Tools, has a smaller shoulder plane that’s almost 3⁄ 4” wide, quite comfortable to use and reasonably priced at $139. I wish the tool was wider, and officials at Lee Valley say I might get my wish soon. Other new and vintage brand names worth checking out include Shepherd Tool (made in Canada) and the British-made Clifton, Record, Preston, Spiers and Norris. Of course, you’ll need to sharpen the tool. And that’s why we offer a free tutorial on sharpening on our web site – click on the “Magazine Extras” link to find it.

Designing a Joint Once you have the tools you need, you can learn about the mechanics of the joint. Study the illustration below to learn what each part of the joint is called. The first question beginners always ask is: How thick and how long should my tenons be? As far as thickness goes, MORTISE & TENON BASICS

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These sample mortises are useful for sizing your tenons. I usually make a new one every season or two, because they can get worn from use.

the rule of thumb is that they should be one-half the thickness of your workpiece. So a tenon on a piece of 3⁄ 4” material should be 3⁄ 8” thick. As for length, that depends on your project. Typical casework tenons that are 1” long will be plenty strong. For large glass doors, make them 11⁄ 4” long. For small lightweight frames and doors, stick with 3⁄ 4”- or 5⁄ 8”-long tenons. What beginners often don’t ask about is the size of the edge shoulders on their tenons. This is a critical measurement. If you make these edge shoulders too small, say 3⁄ 16” wide or so, you could run into huge problems at assembly time when building frames and doors. Here’s why: If your tenoned piece

forms one of the outside members of a frame, your mortise wall is going to be only 3⁄ 16” wide and it’s going to be weak. The hydraulic pressure from the glue or the smallest amount of racking will cause the tenon to blow out this weak mortise wall, ruining everything. It is because of this that I recommend edge shoulders that are 3⁄ 8” wide in most cases. Note that your edge shoulders can be too big. Once they start getting larger than 1⁄ 2”, you run the risk of allowing the work to twist or warp in time, ruining the alignment of the parts. Of course, if your tenoned piece is not on the edge of a frame, you can have narrow edge shoulders without any worries.

A 6" rule will help you set the length of your tenon. Once you do this a couple of times you’ll hit this measurement right away every time.

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Designing the mortise is a bit simpler. It should be the same dimensions as your tenon with one exception: Make the mortise 1⁄ 16” deeper than your tenon is long. This extra depth does two things: It gives your excess glue a place to go and it ensures your tenon won’t bottom out in the mortise, which would prevent you from getting a gap-free joint. Beware of other tune-ups that some books and magazines suggest. One bit of common advice is to chamfer all the sharp edges of your tenons to improve the fit. Another bit of advice is to chamfer the entry hole of the mortise. These are unnecessary if you design your joint properly. One thing that is important, however, is to mark the outside faces on all your parts. It’s important to keep these straight during machining and assembly.

Tenons First Some traditional woodworkers tell you to make all your mortises first and then make your tenons fit that. This is good advice if you cut the joint by hand with a backsaw and a mortising chisel because there is more opportunity for the mortise to be irregular in size. But you will work much faster and with much less measuring if you try it my way. Before you cut your first tenon, you should fire up the hollow-chisel mortiser and make a sample mortise with each size of bit you use. The three most common sizes are 1⁄ 4”, 3⁄ 8” and 1⁄ 2”. These mortises should have perfectly square walls and be 11⁄ 16” deep and 2” long. Write the month and year on each mortise and make a new set next season. Why make these sample mortises? Well, because the tooling to make your mortises will always produce the same width mortise, you can merely size all your tenons to one of these sample mortises as you cut them on your table saw. This will save you time down the road, as you’ll see. With your sample mortise in hand, set up your table saw to cut your tenons. Install the dado stack blades and chippers on the saw’s arbor. The rule here is to install enough blades to almost cut

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Backing board

No wood trapped between blades and fence When making tenons with a dado stack in your table saw, the first pass should remove the bulk of the material. Keep firm downward pressure on your work, which will give you more accurate cuts.

The second pass has the work against the fence and defines the face shoulder. Note there isn’t any wood between the fence and blades, so the chance of kickback is minimal. The backing board reduces the chance of tear-out at the shoulders.

Cut the edge shoulders the same way you cut the face shoulders and cheeks.

the length of the tenon in one pass. For example, to cut a 1”-long tenon, set up enough blades and chippers to make a 3⁄ 4”-wide cut. Next, position your saw’s rip fence. Measure from the left-most tooth of your dado stack to the fence and shoot for the exact length of your tenon. A 1”-long tenon should measure 1” from the left-most tooth to the fence, as shown in the photo above. Get your slot miter gauge out and square the fence or head of the gauge to the bar that travels in the table saw’s slot. Attach a wooden fence to the face of the gauge (usually this involves screws through holes already drilled in the gauge). This wooden fence stabilizes your workpiece and controls tear-out as the dado stack blades exit the cut. Set the height of the blades to just a little shy of the shoulder cut you’re after. You want to sneak up on the perfect setting by raising the arbor of the saw instead of lowering it. This does two things: One, it produces fewer waste pieces that result from overshooting your mark. And two, because of the mechanical backlash inherent in all geared systems such as your table saw, raising the arbor eliminates any poten-

tial for it to slip downward because of backlash. You are now ready to make a test cut. First put a scrap piece up against your miter gauge, turn on the saw and make a cut on the end of the board. Use firm downward pressure on the piece. Don’t let the end of the board touch the saw’s rip fence. Then bring the scrap piece and miter gauge back and make a second pass, this time with the scrap touching the rip fence as shown below. Flip the scrap over and repeat the process on the other face. Usually you aren’t supposed to use your rip fence and miter gauge in tandem, but this is an exception. This cut is safe because there isn’t any waste that could get trapped between the blades and the fence, producing a kickback. Check your work with your dial calipers and see if the tenon will fit your sample mortise. The tenon is likely going

to be too thick. Raise the blades just a bit and take passes on both faces of the scrap until the tenon fits firmly and snugly into the sample mortise with only hand pressure. If you can shake the sample mortise and the tenon falls out, you’ve overshot your mark and need to lower the arbor and try again. If the fit is just a wee bit

Stile

Rail

Mortise ends here

To locate the mortise, put the tenon across the edge of the stile where you want your mortise to go. Use a sharp pencil to mark the tenon’s location on the edge. Bingo. You’ve just laid out the mortise’s location.

Mortise begins here

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By cutting over your line slightly, you give yourself just enough forgiveness at assembly time. A little wiggle can mean a lot when you are trying to close up the gaps as you clamp up your work.

Mortise is cut slightly past that line

Line marked on stile

tight, you can always tune that up with a shoulder plane. Let your dial calipers be your guide. Sometimes you haven’t used enough downward pressure during the cut to make a consistent tenon. If something doesn’t fit when you know it’s supposed to, try making a second pass over the dado stack and push down a little harder during the cut. Using this setup, mill all the face cheeks on all your tenoned pieces. When that’s complete, raise the arbor to 3⁄ 8” and use the same routine to cut the edge shoulders on all your boards. Your tenons are now complete.

Use Your Tenons Like a Ruler One of the major pains in laying out the mortise is figuring out exactly where you should bore your hole. You end up adding weirdo measurements and subtracting the measurements of edge shoulders. If you lay out mortise locations using math only, you will make a mistake someday. Troy Sexton, one of our contributing editors, showed me this trick one day and I’ve never done it any other way since. Say you are joining a door rail to a stile – quite a common operation. Simply lay the tenoned rail onto the edge of the stile and line up the edges of both pieces so they’re flush. Take a sharp 62

pencil and – using the tenon like a ruler – mark where the tenon begins and ends on the stile. That’s it; you’ve just marked everything you need to know to make your mortise. If you are placing a rail in the middle of a stile, there is one more step. You’ll need to mark on the stile where the edges of the rail should go. Then line up the edge of the rail with that mark and fire away. There’s still no addition or subtraction. With all your mortises laid out, you can then get your hollow-chisel mortiser going.

A Finicky Machine I’ve used a lot of hollow-chisel mortisers and find them fussy to adjust. Along with our review of the machines, we published a complete tutorial on the topic in our August 2001 issue. In a nutshell, here are some of the important adjustments not covered by some manuals: • Make sure the chisel is at a perfect 90° angle to the machine’s table. I’ve set up a dozen of these machines and only one has ever been perfect. The solution is to use masking tape to shim between the table and the machine’s base. • Set the proper clearance between the auger bit and the hollow chisel that surrounds it. Some people use the thickness of a dime to set the distance

between the tooling. Some people measure. Either way is fine. If the clearance is too little, the machine will jam and the tooling can burn. Too much distance makes a sloppy-bottomed mortise. • Square the chisel to the fence. The square holes made by the chisel should line up perfectly. If the edges aren’t perfectly straight, your chisel isn’t square to the fence. Rotate the chisel in its bushing and make sample cuts until everything is perfect. • Center the chisel so it’s cutting in the middle of your workpiece. There might be a clever trick to do this, but I’ve found that the most reliable method is to make a test cut and measure the thickness of the mortise’s two walls with a dial caliper. When they’re the same, your mortise is centered.

Simplify Your Mortising As you make your mortises, here are a few tips for making things a whole lot easier. • I like to cut a little wide of the pencil lines that define my mortise. Not much; just 1⁄ 32” or so. This extra wiggle room allows you to square up your assembly easier. It doesn’t weaken the joint much – most of its strength is in the tenon’s face cheeks. • As you bore your mortises, don’t

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Shoulder planes are capable of extraordinarily precise work. Just try to set your table saw to remove .001". It’s not possible. For a shoulder plane, it’s simple.

make your holes simply line up one after the other. Make a hole, skip a distance and then make another hole (see the photo below). Then come back and clean up the waste between the two holes. This will greatly reduce the chance of your chisel bending or breaking. • Keep your chisel and auger lubricated as they heat up. Listen to the sounds your machine makes. As the auger heats up, it can start to rub the inside of the chisel wall and start to screech. Some dry lubricant or a little canning wax squirted or rubbed on the tooling will keep things working during long mortising sessions. • Finally, make all your mortises with the outside face of the work against the fence. This ensures your parts will line up perfectly during assembly.

Final Tweaks No matter how careful you have been, some of your tenons might fit a little too tightly. This is where the shoulder plane shines. Make a couple of passes on both face cheeks and try fitting the joint again. Be sure to make the same number of passes on each cheek to keep the tenon centered on the rail. If your parts aren’t in the same plane when assembled (and they’re supposed to be), you can take passes on only one cheek to try to make corrections. If the joint closes up on one face but not the other, you might have a sloppy shoulder. The shoulder plane can trim the fat shoulder to bring it in line with its twin on the other side of the tenon. If the tenon still won’t seat tightly, try chiseling out some meat at the corner where the edge shoulder meets the face cheek – but don’t trim the outside edge of the edge shoulder itself. Finally, get a sharp chisel and clean out any gunk at the bottom of the mortise. Keep at it – a tight joint is worth the extra effort.

glue using a little scrap piece. I try to leave the glue a little thick at the top of the mortise wall. Then, when the tenon is inserted, this paints the tenon with glue but drives the excess to the bottom of the mortise. When clamping any frame – regardless of the joinery you used – you don’t want to use too much pressure or you will distort the frame. Tighten the clamps until the joints close and no more. You also want to alternate your clamps over and under the assembly to keep the frame flat – no matter how fancy your clamps are. Once you do this a couple of times, I think you’ll find a whole new level of woodworking open to you. Web frames for dressers (or Chippendale secretaries) will seem like no problem. Morris chairs with 112 mortises will be within your reach. And your furniture is more likely to stand the test of time – and maybe even the occasional anvil.

Scrap

A thick bead of glue at the top of the mortise wall makes the joint strong without squeezing out a lot of glue. Use a small piece of scrap to paint the mortise wall before inserting the tenon.

Assembly You really don’t want any glue squeezeout when you assemble your mortiseand-tenon joints. The trick to this is learning where to put the glue and how much to use. I run a thick bead of glue at the top of each mortise wall and then paint the inside of the mortise wall with

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C H A P T E R • 10

Router-made Mortise & Tenon B Y B I L L H Y LT O N

The traditional way to make a mortise is to chop it out with a chisel and mallet; the matching tenon is cut with a backsaw. Fitting is done with a shoulder plane. Every joint has to be marked out. The work is slow and time-consuming, but quiet. Doing it well demands skill. However, the router can do both jobs. It can do them faster, and it can do them better. With the proper setups, you can minimize layout, which saves time. The cuts are accomplished faster (but with more noise). Machine setups produce uniform cuts, which minimizes the need for fitting individual joints. And the mortise

cheeks will be smooth, which means the joints will glue well. I always make the mortises first, then cut the tenons to fit those mortises. The reason is simple: It’s easier to adjust the size of a tenon than that of a mortise. Before I show you how I cut this joint, study the illustration below to familiarize yourself with its parts.

Disposable Mortising Fixture Successfully routing mortises requires a good plunge router and a good fixture to hold the workpiece. Over the years I’ve tried a variety of fixtures. In design-

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ing one, you have three challenges. You must: • Provide adequate bearing surface for the router base to keep it from tipping. • Position the router and control its movement so every mortise is identical. • Minimize the workpiece handling. The drawing and photos show that this fixture is simple to build and use with a plunge router and an edge guide. The more precise your edge guide, the more accurate your mortises will be, particularly in terms of placement on the edge. The width of the mortise is

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determined by the diameter of your bit. The router’s plunge mechanism controls the mortise depth. The basic fixture, made from scraps, has five parts: a base, two supports (or fences) and two stops. The supports are attached to a plywood base with drywall screws. The router stops are screwed (or clamped) to the top edge of the long support.

A setup line is squared across the edge and down the face of the long support, equidistant from the ends. Align the midline of the mortise – the only layout mark needed on all but one of the workpieces – with this line. Your router, edge guide and the stops will ensure that each mortise is uniform in placement, width, depth and length. The upshot of this fixture is that it’s

easy to make and is disposable. Make one for a particular job, use it, then dismantle it and recycle the scraps for something else. If you are so inclined – and I haven’t been so far – you can make a spiffy model with sliding stops and a built-in work clamp.

Photos by the author

Long support Setup line

Workpiece midline

Align the midline of the mortise with the jig’s setup line, then clamp the work to the jig’s long support using an F-clamp.

The jig provides support under each plunge post, which enables you to plunge your router smoothly. When cutting, move the router in the proper direction, so the bit’s rotation pulls the edge guide against the support.

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Stop plate

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ROUTER TABLE TENONING SLED

Using the Fixture Clamp the fixture to your bench and chuck the bit you want to use in your router’s collet. Mount the edge guide on the router. Lay out a sample mortise on a scrap, including the midline mentioned above. I wouldn’t use an actual workpiece, but I always use a piece of the working stock. Thickness is critical to the setup. The mortise layout must clearly define the mouth of your mortise. Set the sample in the fixture, align it with the setup line and clamp it to the long support. Set the router on the fixture and plunge the bit down to the stock. Align the bit within the layout lines and set the edge guide, cinching down its screws. With the bit still bottomed against the work, zero out the router’s depth adjuster and reset it for the depth you want. Finally, set the router stops, which control the mortise length. Move the bit so it aligns with one end of the mortise. Set a scrap on the long support against 66

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the router’s base and attach it to the fixture. Move the router to the other end of the mortise, align the bit, then attach the second stop. Move the router to the appropriate end of the mortise for bit rotation, switch it on and plunge the bit about 1⠄8� into the work. Make a cut and retract the bit. At this point, you can remove your sample from the fixture and measure the mortise shoulders. Assuming the mortise is to be centered, you want them equal. Adjust the edge guide as necessary to center the cut. (If the mortise is intended to be centered on the work and your edge guide is less than precise, here’s a trick. After routing the mortise to its full depth, unclamp the work and turn it around. Align the setup lines and reclamp the work. Re-rout the mortise. While it now will be wider than the bit, it will be centered. When you rout the matching tenons, simply cut them to fit the mortise.) Now you can clamp a fresh sample in the fixture and make a full-depth

mortise. Never remove more than about 1⠄ 8� of material in a single pass with your plunge router. If the sample mortise is properly located and it’s the correct length and depth, you should be ready to rout the good stuff.

Routing Tenons A good tenon has straight, square shoulders and smooth cheeks (smooth surfaces glue best). Gaps and misalignments at the shoulder not only degrade the joint’s appearance, they weaken it. You want a clean and square intersection of the shoulder and the cheek – no ridges of waste, which could prevent the joint from closing completely. The shoulders must be in the same plane all the way around the workpiece so they’ll seat tight against the mortise’s shoulders. Router-cut tenons meet all these criteria and they’re easy to make. While there are a variety of ways you can rout tenons, my favorite is with a router table and a simple jig. You can set this up in just a few minutes, you don’t have any

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Position the stop by measuring from the shoulder of the cut in the sled’s fence. Use the same bit for tenoning so the shoulder cut remains accurate for setups and for backing up the tenon shoulders.

layout to do, and you can cut a typical tenon in four passes. The key is the bit. Most manufacturers call it a mortising bit (intended for hinge mortising), but some call it a planer bit. The bit is designed to cut on the horizontal surface as well as the vertical. Thus it’s perfect for tenoning, where you want shoulders square to cheeks and both surfaces smooth. Mortising bits are available from many manufacturers with both 1⁄4” and 1⁄ 2” shanks and in diameters up to 11⁄ 2”. With the biggest size, you can cut a typical tenon’s cheek in a single pass. Even a bit that large can be run safely at the router’s full speed. I guide the work with an easy-tomake sled that’s essentially a short, stocky T-square. The sled rides along the tabletop edge so you get a straight, consistently placed shoulder cut. The fence holds the workpiece and backs up the cut, so you don’t get tear-out. A stop clamped to the fence sets the tenon length. The sled is simple to make, but be careful about some details. Specifically, the shoe must be perpendicular to the jig fence, the edge of the fence must be perpendicular to the tabletop and the stop must be perpendicular to the edge of the fence and the tabletop. Misalignment of

Cutting your tenon takes only one pass per cheek. Lay the work on the table, pull it against the sled’s fence and stop and feed it across the bit. The bit cuts the cheek and shoulder simultaneously.

any of these reference surfaces can result in skewed tenons and shoulders.

Using the Sled The first thing is to install the bit in the router and set its elevation. Use a rule to measure the exposure of the cutting edge above the table. I set the bit just under the width of the mortise’s shoulder; that way, I can creep up on the right setting (determined by fitting a test tenon in a mortise) with test cuts. Set up the sled next. Set the stop on the sled’s fence to establish the tenon length. To do this, measure from the cut made into the fence by the bit. (You always want to use the same bit with the sled; otherwise you will get tear-out.) If the tenon is to be 11⁄8” long, as shown in the photo at right, align the 11⁄8” mark on the rule at the edge of the cut. Slip the stop onto the fence and bring it against the end of the rule. Seat it firmly so it’s square to the fence and the tabletop. Tighten its clamp. Then cut a sample tenon to check the setup. Make one pass, cutting the first cheek and shoulder. Roll the workpiece over and cut the second cheek and shoulder. Check the fit of this tenon in your mortise. You need a close fit for the joint to glue well. If you have to hammer the

tenon to close the joint, the fit is too tight. Hand pressure should close it. But don’t make it too loose, because the joint should stay closed until you separate the parts. Obviously, “plain vanilla” tenons, which have the same width of shoulder all around, are the easiest to cut. An offset tenon or one with wider or narrower edge shoulders takes one or two more setups. In any case, your square-cornered tenon doesn’t match your routed mortise, with its rounded ends. You can resolve this problem in one of several ways. Some address it by squaring the ends of the mortise with a chisel. I’ve often rasped the tenon’s corners to roughly match the mortise. A third option is to scale the tenon width to fit the mortise. The primary glue surfaces are the broad cheeks, and you’ve got the shoulders working to resist twisting and racking. If the narrow edges of the tenon aren’t in contract with the ends of the mortise, it doesn’t significantly impact the strength of the joint.

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C H A P T E R • 11

Template Mortising B Y B I L L H Y LT O N

Template mortising is an excellent technique for all sorts of special mortising challenges. It works for everyday mortising applications as well, but most of us already have an established setup for making door frames, leg-and-apron constructions, and the like. Where I use templates for mortising is any application that can’t easily or accurately be done with a hollow-chisel mortiser or my setup that uses a plunge router, edge guide and mortising block combination. For example: • Any mortise in the face of a panel. • A difficult-to-position mortise, such as one in a round part, one cut into the arris of a leg, one cut into an alreadyshaped part, or one to be cut at an angle. In these situations, the use of a template allows you to make a cradle that immobilizes the workpiece and provides a flat, sound, bearing surface for the router. • Multiple mortises, such as those needed for spindles in a chair backrest, twin mortises that join stocky rails to posts, double mortises that join a very wide rail to a leg. A template eliminates the little variations in mortise size or spacing that can make assembly of these constructions especially trying. • A mortise in a part, such as a chair leg, that itself is shaped using a template. You can incorporate the slot for the mortise into the template for shaping the part. Here’s how a mortise template works: The template is a flat piece of plywood or Medium-density Fiberboard. It has a slot or a window that’s actually larger than the mortise you want. To make the 68

Templates are an effective way to make multiple, identical mortises. With them, you control both size and location in one step.

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Up-spiral bit Template slot length

Template guide Workpiece

Template

This template slot is 3 ⁄ 4" wide, and the mortise is 5 ⁄ 16" wide. The big differential between bit size and guide bushing size, coupled with dust extraction on the router, helps clear the chips as you cut.

Mortise length

To the length (or width) of the mortise add twice the offset to determine how long (or wide) the opening in the template must be.

cut, you use a router (preferably a plunge router) fitted with a template guide. The guide’s protruding collar is trapped in the template slot, limiting the router’s movement. The only cut the router can make is exactly the cut you want.

With the bit aligned for the end of the slot, set a scrap against the router base and clamp it. Note that the template blank is set on a sacrificial piece of plywood that protects the benchtop.

Offset

Guide Bushings The pivotal gadget in the operation is a template guide, sometimes called a guide bushing or guide collar. It looks a lot like a big washer with a short tube projecting from it. The “washer” fits into the bit opening in the router base and the bit extends through the tube, which usually is called the collar. The collar rides along the edge of the template, just the way the pilot bearing on a bit does. But unlike a pilot bearing, this guide doesn’t move when you change the extension of the bit. Consequently, you can contact the template edge with the guide, then plunge the bit into the work and make a cut. Plunge deeper and deeper to excavate the mortise, and all the while, the guide

is in contact with the template, controlling the router. Obviously, the bit has to be smaller than the inside diameter of the collar. A number of issues come into play in pairing a guide with a bit for template mortising. One is the flow of chips out of the cut. Unless there’s a good reason for keeping the guide as small as possible, I like to provide good clearance between the bit and collar to allow the chips to clear the cut – using a 5⁄8” or 3⁄4” guide with a 3⁄8” bit, for example. Guide bushings are manufactured with collars (those projecting tubes) ranging in length from 1⁄4” to 9⁄ 16” (the larger the diameter, the longer the collar). This is intended to help stabilize the router on edge cuts, when most of the router base is largely unsupported. That little extra length can be beneficial. The trade-off is that with the larger guides, you have to use templates at least 5⁄8” thick, and that extra thickness is subtracted from the depth-of-cut capacity of your plunge router. Success with template mortising begins with a precision template. Lay out the mortising slot on a line drawn parallel to an edge of the template blank. Before routing the template slot, use a V-groove bit in the router to align the tool on the line (inset) and set the edge guide (left). Then switch to a straight bit to rout the slot.

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In most cases, you’ll want a fence on the template so you can position the template quickly and accurately on a workpiece. Plane a gauge strip to half the working stock’s thickness. Clamp it to your fence, then align it at the centerline laid out on the template. Clamp the fence to the template. Run two or three screws through the template into the fence.

If you have a string of shallow mortises to cut in several parts, using a template to rout them can ensure the mortises are uniform across the run of parts. Invest the time to make a precision template. Typically, workpiece layout is eliminated, as are minor variations in mortise size and spacing.

If this becomes a problem, you can easily cut down a collar. Use a hacksaw or a bench grinder. I’ve trimmed most of my guides to just less than 1⁄4”, so I can use them with 1⁄4”-thick templates. That adds 1⁄2” to the depth of a mortise I can rout with a template, and in a few instances, that’s been a big help. What bit should you use? If you are routing a commonplace mortise, say 3⁄8” wide by 2” long and 1” deep, you’d use a 3⁄8”-diameter bit. In this regard, template mortising is no different than other approaches. For mortising, I do prefer up-spirals, but I’m not doctrinaire about it. I’ve often used regular straight bits in oneand two-flute configurations. But spirals cut cleanly, reduce the stress on the router, and help pull chips out of the cut. (This can be especially helpful because the template-guide can block the escape of chips. They can only exit through the 70

clearance gap between the collar and the bit.)

Making the Template First calculate the size of the slot or window that’s necessary to produce the desired mortise. If the mortise width matches the cutter diameter, the template slot should match the diameter of the guide being used. To determine the slot length, you have to add twice the offset to the mortise length. Offset is the difference between the radius of the guide and the radius of the bit. If you’re using a 3⁄8” bit in a 1⁄2” guide, the offset is 1⁄16”. Thus, if the mortise is to be 2” long, the template slot must be 21⁄8” long. If you opt for a larger-diameter guide, then the slot must be both wider and longer. Making the template is as simple as routing a blind slot. Lay out the slot, then cut it with a plunge router and edge

guide. Or cut it on the router table. In most instances, the mortise length isn’t a critical dimension. By that I mean, the exact length – to the 32nd of an inch – is not as important as having all mortises be the same. Some woodworkers are completely comfortable briskly laying out the slot, then cutting it by eye from mark to mark. I guess I’m just a little compulsive, so I use a V-groove bit in the router to set the edge guide and to set stops for the router to govern the slot length, as shown below. Hand-tighten the V-groover in the collet and plunge it to the template surface. Set the point right on your layout line and bring the edge guide against the edge of the stock. Slide the router along the stock to be sure the bit tracks on the layout line. Then position the V-groover on the end point. Set a stop block against the router base and clamp it to the stock, as shown below.

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Where a mortise is located in the face of a panel, use cross hairs to position the template. Lay them out on the template blank to guide the cuts that create the “window.” Lay them out on the panel, to delineate where the template must be placed.

A plunge router with some form of dust extraction is best for template mortising. Without it, chips can foul the template slot. The template is a solid platform that supports the router under both plunge posts.

Move the router and set the second stop block. (Bear in mind that the cut will be longer than this setup by the diameter of the bit. You have to account for the bit when you lay out your marks.) With the edge guide and stops set, swap bits to actually cut the slot. If you have more than one slot to make in the template (for doing twin mortises or double mortises, for example) you cut them similarly. Making a second slot in line with the first is a simple matter of moving your stops to new locations. Making a parallel slot can be easily accomplished by switching the reference edge or adjusting the edge guide.

Locating the Template Your next hurdle is locating the template on the workpiece and securing it. You should know exactly what you’re going to do, of course, because that was all part of your initial plan. Right? How you do it depends, obviously, on the size and shape of the workpiece. A template for a mortise in a panel may be positioned using the cross hairs of a center line and a midline, laid out to aid in routing the slot, as shown below. You might use carpet tape or hot-melt glue to attach the template for the cut.

I’ve actually screwed the template to the part in a few cases. For commonplace work such as stiles or legs, you can mount a fence to the template. Then you clamp the part to the fence. A stop attached to the fence can position the work so you don’t have to lay out each piece. Or that midline can be your registration mark. Use the laid-out centerline as a reference for mounting a fence and a gauge block to position the fence in relation to the line. Plane a piece of stock to the appropriate thickness. If the mortise is to be centered across the edge of the workpiece, that thickness would of course be half that of the working stock. Align an edge with the layout line and clamp the block to the template, as shown above. Apply glue to the edge of the fence. As you press the glued edge to the template, slide the fence tight against the gauge, and clamp it to both the template and to the gauge. Then you can turn the assembly over and run a couple screws through the template into the fence. (Just don’t glue the gauge to the assembly!)

Cutting the Mortise Cutting the mortise is a job for a plunge router. Install the guide bushing and chuck the bit in the collet. Set the router

on the template, guide collar captured in the slot. Bottom the bit against the workpiece, zero out the adjuster, then set the depth of cut. The routine is to move the router back and forth, cutting progressively deeper. “Proper” feed direction becomes irrelevant. The template reins in the router, allowing it to move only on a defined line and distance. Release the plunge mechanism to raise the bit before lifting the router from the template. What’s going to happen is that chips will clog both the cut and the slot in the template. You need to interrupt the cutting periodically to vacuum out these chips. If you don’t, and you focus doggedly on getting it routed, you’ll get chips packed so tightly in the ends of the template slot that you’ll need to dig them out with a narrow chisel or an awl. Dust extraction as you rout is a major boon. I almost always use DeWalt’s DW621 for mortising, primarily because of that router’s dust extraction system. (This isn’t a knock against built-in or add-on dust extraction available on other brands and models, few of which I have actually tried. The 621’s system works for me and that’s what I use.) In most instances, dust extraction reduces interruptions. T E M P L AT E M O R T I S I N G

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C H A P T E R • 12

Frame Miter Joints The only frame joint that doesn’t leave a bit of end grain exposed is the miter joint. Given that it’s almost invisible when done right, it’s visually appealing, so you see it used for picture frames, for architectural trim, when assembling mouldings and occasionally in face or door frames. But it can be a problematic joint. Structurally, it’s a bit weak. Because it mates one tangentially cut end-grain surface (sometimes called “short grain”) with another, it’s weaker than a longgrain-to-long-grain joint. It’s stronger than end-grain to end-grain, but not much. Run some fasteners into a miter joint and you’re driving them into end grain, where they won’t hold well. Angling the fasteners helps, but not a lot. Also, a miter is tough to cut accurately. Haven’t we all struggled with a frame that isn’t square and has joints that don’t close because some of the cuts were half a degree off perfect? Try all sorts of approaches – miter saws, table-saw jigs, stationary sanders, even hand tools such as block planes and miter trimmers – but nothing seems to work. On top of that, joint assembly is maddening because you have to find a way to prevent the mating pieces from sliding out of line when you apply clamping pressure. If that isn’t enough to make you shy away, wood movement stresses the joint and degrades its appearance, especially with stock that is wider than 3”. As the wood expands, the joint tends to open at the outside; when it contracts, the joint opens at the inside. The wider the stock 72

Photos by the author

B Y B I L L H Y LT O N

Spline and dovetail keys are basically just exposed splines. After the joint is glued up, just saw or rout a slot through its edge, then glue a key into the slot. Typically, the key is a contrasting wood so it can stand out.

Contraction: Wood gets narrower but not shorter – miter opens at inside corner

EFFECT OF WOOD MOVEMENT

Expansion: Wood gets wider but not longer – miter opens at outside corner

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and the more unstable the species, the more pronounced the effect. For this reason, it’s a good idea to limit the stock width you join with miters. Picture framers and trim carpenters compensate for this effect by layering several thinner mouldings to create large frames.

Making the Cuts Cutting the miters seems to be a simple task. You can use several different types of power saws, but the real trick is in cutting a precise angle that yields a square joint. Power miter saws and radial-arm saws have adjustment points that can create inaccuracies. A detent (a factorymade “stop” for the blade at common cutting angles) can have just a tiny bit of play. The pointer on the scale can be off a hair. The tools have pivot points that can develop play. Nevertheless, these tools will produce acceptable results. And having a well-tuned saw helps. When you make a critical cut, check the angle against a reliable angle square. For 45° angles, a plastic drafting triangle is both accurate and inexpensive. The other critical point is that your stock must be cut precisely to length. Even small variances can spoil the fit of the assembled frame. A woodworker who gets little practice may get better results using a sliding crosscut table or a miter sled on the table saw. Sliding tables are pricey, and not all saws can accommodate one. An adjustable miter sled is more reasonably priced. Or you can make one yourself, as shown at right. The advantage of these devices compared to a miter gauge is that the work is immobilized against the fence and base throughout the cut – you aren’t sliding the work itself across the table of the saw. Presuming that your goal is to produce a square corner and not necessarily to produce precise, individual 45° cuts, you can make a miter sled for the table saw that will do the trick. A square-cornered block ensures that your assembled miters will be square. While there’s certainly more than one

Fence cutout provides clearance for long stock

11 7/16"

Kerf fence after assembly 90o angle essential

1 1/16"

3 1/2" Back block

22 7/8" 24" Base - 3/4" plywood, MDF or melamine

Use kerf in base to align miter fence for mounting 1/16"

16"

MITER SLED

Hardwood runners

Aluminum angle fence extension

A miter sled for the table saw will produce perfect right-angle joints. Stops clamped to the aluminum angle fence extensions ensure parts will be properly sized.

way to produce the sled, the one that worked for me was to assemble the base, runners and fence, then to saw into the base. I next cut the back block square, scribed the diagonals on the block and sawed it in half along one of them. I used the second scribed diagonal to position the now-triangular block on the sled’s base. The result is a sled that helps me cut clean miters that form perfect right-angle joints. No fuss, no adjustments and no fine-tuning are required.

Clamping is Job No. 1 The true challenge in gluing up a miter joint is applying clamping pressure. You need to force the mating surfaces togeth-

er, which requires pressure perpendicular to the glue line, but you also need to simultaneously pull the components of the frame together. There are all sorts of specialty clamps on the market. You can buy corner clamps for clamping individual miter joints. There are some setups for clamping a complete frame at once. An effective and inexpensive band clamp, for example, surrounds the frame and pulls its parts together. I personally favor some homebrewed approaches that use general-purpose clamps. Miter clamping cauls provide angled surfaces so you can apply a clamp perFR AME MITER JOINTS

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Miter clamping cauls help you apply pressure at right angles to the joint’s seam.

V-grooves

Cleat Wedge

Cleat

V-block V-block

Wedge

Screw V-blocks to a plywood base to make a frame-clamping jig. Pressure is applied with pairs of wedges. Positioning the blocks – using frame parts – before gluing the frame takes only a minute or two.

Packing tape holds glued miters together while you apply V-blocks and clamps. Apply bar or pipe clamps on the diagonals and alternate tightening to avoid distorting the frame.

pendicular to the glue seam. Clamp the cauls to the mating parts, then close the joint and apply the clamp to it. Two cauls allow you to clamp a single joint and they work equally well for clamping case miters. You can make them by cutting V-grooves to create the clamping surfaces, or you can attach beveled blocks 74

to strips of plywood. You also can use four clamping blocks with V-shaped notches cut into them. This works where you want to assemble four joints at once – a complete frame – as opposed to just one joint at a time. One way to use the blocks is to mount them to a base. The base provides

a flat surface to ensure the frame isn’t twisted, and the V-blocks capture the frame corners to ensure they are square. It’s particularly useful for multiples and for very large frames, where the support of the base is beneficial. I set up the board after at least one frame is cut so I can use its parts to position the blocks that are screwed to the base. Note that only two of the V-blocks are screwed to the base. At the other two corners, you fasten cleats to the base. Clamping pressure is applied by twin wedges driven between the cleats and the loose V-blocks. To prevent squeezeout from bonding the frame to the base or blocks, wax them liberally. For the one-off frame, you can use the V-blocks with a brace of bar clamps and several strips of packing tape. Glue the frame and secure each joint with packing tape. Set the V-blocks at the frame corners and apply the bar clamps diagonally. Alternate from clamp to clamp as you tighten them to avoid distorting the frame.

Call for Reinforcement I’ve found that miters can be reinforced in a number of different ways. • Picture framers commonly use nails. The joint needs to be securely clamped so the hammer’s impact doesn’t knock the parts out of kilter. Bear in mind that nails driven straight into end grain don’t hold that well. You can improve the joint slightly by driving the nail on an angle to the grain. • Splines are pretty easy to incorporate, and you can hide them inside the joint. (Splines were discussed in the October 2003 issue of Popular Woodworking – available at popwood. com – so we won’t repeat that here.) • Biscuits also can be used. If the frame members are more than 21⁄ 4” wide, you can use standard No. 20 biscuits. You can use smaller biscuits – No. 10s, No. 0s or mini-biscuits – for narrower frames. • Dowels are another option, but they are tricky to align, so I don’t recommend using them with this joint.

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Unlock the ‘Keys’ A reinforcement I like for frame miters is the key, either a spline or a dovetail, to add a subtle embellishment to the joint. Make sure you cut a slot for the key after the joint is glued. For a deep slot – one cut into a wide frame – you can make it on the table saw, while you can cut a shallow slot using your the router table. The jig shown at right works on either the table saw or the router table. On the latter, you can use it by sliding it along the fence to cut with a bit or by sliding it across the tabletop to cut with a slot cutter. This approach enables you to use a dovetail key, but the table saw can make a much-deeper cut, which is important for frames that have wide members. Construction should be evident from the drawing. Miter the ends of the two frame supports, then glue and screw them to the plywood back. These supports must be at right angles to each other. In this form, it can be used flat on the tabletop. If you use the jig upright braced against the fence, add the fence hook (seen in the photo at right) to it. However you orient the jig, the frame is set into it. You can hold it tight with a spring clamp or two. Position the jig and frame against the fence and make the cut. When using splines, you should make the cuts on the table saw. Rip strips of stock – a contrasting wood is preferred – to the appropriate thickness. If necessary, plane them to fit. Crosscut the strips into little triangles and glue one into each slot. When the glue dries, trim them flush. Dovetail keys are easiest to cut on a router table. After slotting the frame, cut the keys using the same bit and height setting. The only change in setup is to swing the fence over the bit, housing most of it. Start with an oversized pin and methodically trim it to fit the slot. When you’ve got a good fit, rip the pin from the board. Repeat the process until you have enough key stock. Then you can simply cut the stock into short keys and glue a key into each slot. When the glue dries, the keys must

be trimmed flush. Saw off the keys as close as possible, then trim the remaining stubs flush with a block plane (work from the corner in, so you don’t tear out splinters of the keys) or sand the stubs flush.

16"

90o Fence height 8"

FRAME SPLINING JIG

Fence width

Fence hook You can cut slots for spline keys on the table saw. A shop-made jig that straddles the rip fence holds the assembled frame.

You can cut slots for dovetail keys on the router table using the same type of jig. The slot can be centered easily by turning the frame around in the jig after the initial cut, then making a second pass.

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C H A P T E R • 13

Compound Miter for Dummies BY NICK ENGLER

Well, this is embarrassing, I thought to myself. Steve, Tricia and Al — a large part of the Pop Wood team — had made a pilgrimage to my shop to take photos of an expert craftsman making flawless compound miter cuts. And I couldn’t remember how to do it. “Wait just a minute,” I told them. “I’ve got a book right here that tells what to do.” I reached for a copy of “Nick Engler’s Woodworking Wisdom” and read my own instructions on the technique. Making compound miters — a miter joint that is both angled and beveled — is one of those special techniques that most woodworkers need only once in a great while. It’s a neat trick with intriguing results. When you join the frame members, the boards have a slope so the assembled shape tapers from one edge to the other. You can employ compound miters to make picture frames, bowls, pedestals and dozens of other projects such as the Two Tub Tables on the following pages. Trouble is, it’s not a technique you’re likely to use every day, or even every month. In between the times when you need it, you’re likely to forget some of the finer points — I know I do. So I’m going to write this article as a “refresher course” in compound mitering, as much for myself as all of you.

Figuring the Angles When cutting a compound miter on a table saw, you must set both the miter angle of the miter gauge and the bevel angle of the saw blade. These angles depend on two things — the number of 76

sides in your frame and the slope of the assembled frame. The slope, by the way, is usually measured from horizontal, with the frame resting on a flat surface. For every frame and slope, there is just one pair of angles, and these angles must be precise or the miter joints will gap. To find these angles, woodworkers of yore went through a convoluted drafting process that takes two days just to explain. Contemporary craftsmen either use some simple equations or they refer to a compound miter chart. I prefer the chart method myself, so I’ve included one with this article that lists angle pairs for lots of frame assemblies and slopes. But just in case you don’t see the angle settings you need for your particular project, here are the equations:

the miter angle for a four-sided mitered frame with a 30-degree slope, find the cosine of the slope by entering 30 on the keypad and then pushing the cos button. The result should be 0.8660 and change. Next, multiply the number of sides (4) by 2 and divide the result (8) into 360 — the result is 45. Find the tangent of 45 — that’s right, just push the tan button on the calculator. Multiply the result (1) times 0.8660, then divide that number (0.8660) into 1. The answer is 1.1547 — that’s the tangent of the miter angle. To convert this tangent into an angle, press the INV (or “inverse”) calculator button, then the tan button. Your miter angle is 49.1074 degrees. Always figure the miter angle first, then the bevel angle. You need the

Miter Angle (for all joints): tanMA = 1 ÷ [cosS x tan(360 ÷ 2N)] Bevel Angle (for mitered joints): tanBA = cosMA x tanS Bevel Angle (for butted joints): tanBA = cosMA ÷ tanS Where: MA is the miter angle; BA is the blade angle; S is the slope; N is the number of sides.

If you’re mathematically challenged, don’t despair at the mention of tangents and cosines. I too slept through high school trigonometry. But I still work a trig equation now and then by pounding on a scientific calculator. These have special buttons marked sin, cos and tan to simplify the functions — trigonometry for dummies. For example, if you want to figure

To check your setup, cut enough small pieces to make a complete frame. Clamp a stop to the miter gauge extension so each piece is identical.

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cosine of the miter angle to calculate the bevel. Note that the bevel angle equation is slightly different depending on whether you want to make the joint mitered (with the seam at the corner) or butted (with the seam visible on one side). On the chart, I’ve rounded the angles to two decimal places. There probably isn’t a table saw on the planet that can measure hundredths of a degree, let alone the eight decimal places you’re likely to get from your calculator. But this will help you guesstimate where to set the pointer between two degree marks on the miter gauge scale and the blade tilt scale.

Cutting the Angles Now for the easy part — and the part I always forget. Once you’ve set the miter and bevel angles, there’s a nifty trick for cutting both the right and left miters on the frame members without having to change settings. It’s all in how you flip the board. I prefer to cut compound miters with a long miter gauge extension (a board fastened to the face of the miter gauge) that extends well past the blade. This not only provides better support, it gives you a surface to fasten a stop so you can make precise duplicate parts. To make the first cut, place the board against the miter gauge extension and feed it into the blade, cutting through both the board and the extension. Flip the board edge for edge, so another edge rests against the extension and another face rests against the table. The board ends should remain oriented as they were. Position the board for the second cut and feed it into the blade. If the second cut is near the end of the board, and there isn’t enough wood for you to hold it safely against the extension, move the miter gauge to the other slot on the opposite side of the saw blade. You won’t need to change the settings. Adjusting the Angles Before cutting good wood, it’s always a good idea to make some test cuts to check your setup. I cut enough small identical pieces to make one frame, 78

Here’s the compound miter technique in a nutshell. Angle the miter gauge, tilt the blade, make your first cut, flip the board edge for edge, and make the second cut. You’d think I could remember that.

then assemble it with masking tape to check the joints. If the settings are off, one of the compound miter joints will gap. When the gap opens to the outside of the frame, increase the bevel angle. When it opens to the inside, decrease the angle. This may change the slope very slightly, but usually not enough to notice.

Assembling the Frame The best clamps I’ve found for gluing up compound miters are band clamps. If the slope is fairly steep, wrap the band clamps around the corners of the frame as you would when assembling a box. As the slope becomes shallower, however, the clamps tend to slip up the slope. When this is the case, wrap the clamps around edges of the assembled frame members, like the ribbons on a Christmas present. Be careful not to overtighten the clamps or the frame members will bow. If you can’t get enough clamping pressure without bowing, use additional band clamps and position them as close to the corners as possible. Control the bowing by wedging a scrap between opposite members to act as a temporary brace. In some compound miter assemblies with multiple sides, I’ve seen craftsmen put the members together in several steps. They assemble two halves, then sand or joint the adjoining surfaces of the halves for a tight fit, and glue the halves together. This is commonly done when gluing up blanks for lathe turnings

where the strength of the glue joints are critical and even the tiniest gap in a joint could spell disaster when the stock is spinning at a high speed. To calculate compound miter angles, you need a scientific calculator (about $12 at most office supply stores) with SIN, COS, TAN, and INV buttons. On some calculators, the INV button is labeled FUNC for “function.” If you have a computer and use Microsoft Excel software, you can download a simple Compound Miter Calculator that I wrote from the Pop Wood web site: www. popwood.com

Tape the pieces together at the corners and inspect the joints. If you find any gaps, adjust the bevel angle in tiny increments and cut new test pieces until the gaps disappear.

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Compound Miter Chart for the Table Saw SLOPE°

4 SIDES BUTTED MITER BEVEL ANGLE ANGLE

4 SIDES MITERED MITER BEVEL ANGLE ANGLE

5 SIDES MITERED MITER BEVEL ANGLE ANGLE

6 SIDES MITERED MITER BEVEL ANGLE ANGLE

8 SIDES MITERED MITER BEVEL ANGLE ANGLE

0

45

90

54

90

60

90

67.5

90

5

45.11

3.53

54.1

2.94

60.09

2.5

67.58

1.91

10

45.44

7.05

54.42

5.86

60.38

4.98

67.81

3.81

15

45.99

10.55

54.94

8.75

60.85

7.44

68.19

5.69

20

46.78

14

55.68

11.6

61.52

9.85

68.73

7.52

25

47.81

17.39

56.64

14.38

62.38

12.2

69.42

9.31

30

49.11

48.59

49.11

20.7

57.82

17.09

63.43

14.48

70.27

11.03

35

50.68

42.14

50.68

23.93

59.24

19.7

64.69

16.67

71.26

12.68

40

52.55

35.93

52.55

27.03

60.9

22.2

66.14

18.75

72.4

14.24

45

54.74

30

54.74

30

62.81

24.56

67.79

20.71

73.68

15.7

50

57.27

24.4

57.27

32.8

64.97

26.76

69.64

22.52

75.09

17.05

55

60.16

19.21

60.16

35.4

67.38

28.78

71.68

24.18

76.64

18.26

60

63.43

14.48

63.43

37.77

70.04

30.59

73.9

25.66

78.3

19.35

65

67.09

10.29

67.09

39.86

72.93

32.19

76.29

26.94

80.07

20.29

70

71.12

6.72

71.12

41.64

76.05

33.52

78.83

28.02

81.94

21.07

75

75.49

3.84

75.49

43.08

79.35

34.59

81.5

28.88

83.88

21.7

80

80.15

1.73

80.15

44.13

82.81

35.37

84.27

29.52

85.89

22.12

85

85.02

0.44

85.02

44.78

86.38

35.82

87.12

29.87

87.93

22.43

90

90

0

90

45

90

36

90

30

90

22.5

SLOPE°

4 SIDES BUTTED MITER BEVEL ANGLE ANGLE

4 SIDES MITERED MITER BEVEL ANGLE ANGLE

5 SIDES MITERED MITER BEVEL ANGLE ANGLE

6 SIDES MITERED MITER BEVEL ANGLE ANGLE

8 SIDES MITERED MITER BEVEL ANGLE ANGLE

0

72

90

75

90

78.75

90

81

90

82.5

90

5

72.06

1.54

75.05

1.29

78.79

0.97

81.03

0.78

82.53

0.65

10

72.26

3.08

75.22

2.58

78.92

1.94

81.13

1.56

82.61

1.3

15

72.58

4.59

75.49

3.84

79.12

2.9

81.3

2.32

82.75

1.94

20

73.02

6.07

75.87

5.08

79.41

3.83

81.53

3.07

82.95

2.56

25

73.59

7.5

76.35

6.28

79.78

4.73

81.83

3.79

83.2

3.16

30

74.28

8.89

76.94

7.43

80.23

5.6

82.19

4.49

83.5

3.74

35

75.1

10.21

77.62

8.54

80.75

6.42

82.61

5.15

83.84

4.3

40

76.02

11.46

78.4

9.58

81.34

7.2

83.08

5.77

84.24

4.81

45

77.06

12.62

79.27

10.55

81.99

7.93

83.61

6.35

84.68

5.3

50

78.2

13.7

80.23

11.43

82.71

8.6

84.19

6.88

85.16

5.74

55

79.44

14.67

81.26

12.24

83.49

9.2

84.81

7.36

85.68

6.14

60

80.77

15.53

82.37

12.95

84.32

9.73

85.47

7.79

86.23

6.5

65

82.18

16.27

83.54

13.56

85.19

10.19

86.17

8.15

86.82

6.78

70

83.66

16.88

84.76

14.09

86.11

10.56

86.9

8.45

87.42

7.05

75

85.19

17.38

86.03

14.49

87.05

10.87

87.65

8.7

88.05

7.24

80

86.77

17.72

87.34

14.75

88.02

11.09

88.42

8.89

88.69

7.39

85

88.38

17.91

88.66

14.97

89.01

11.17

89.21

8.96

89.34

7.5

90

90

18

90

15

90

11.25

90

9

90

7.5

Note: The slope is measured from horizontal, with the assembly resting on a bench or work surface.

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C H A P T E R • 14

The Case for Case Miters B Y B I L L H Y LT O N

Try this with a garden-variety case miter joint. The lock miter joints hold your parts together on their own, freeing both your hands to apply clamps.

80

Photos by the author

What joint would you use at the corners of a case? If appearance is a consideration – when is it not? – you definitely don’t want an ugly joint like a rabbet. No matter how thin, that strip of exposed end grain – the butt of the board – is unattractive. From the standpoint of what looks best, the miter joint should be atop your list. The only surfaces visible are the attractive ones: the faces and the edges. If you are making a small chest and you have a wide, long board with killer figure, you can wrap that figure around the corners without interruption. You may think of the case miter as being difficult in subtle ways. Well, yes, it can be. If the joinery cuts are off by a degree or two, the joint isn’t going to be square no matter what you do. Gluing and clamping the parts can be an exercise in torment and despair. There’s no mechanical interlock to hold the parts in alignment, and glue just enhances the natural tendency of the surfaces to creep. Moreover, despite the fact that a miter joint has more gluing surface than a butt joint, the glued miter joint isn’t that strong. The shortcoming is that the miter brings end grain to the glue-up session. But simple solutions to these and other difficulties do exist, and the results make it a joint worth mastering.

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Case Miter Varieties Let’s look first at some of the ways the joint can be shaped to reinforce it, and to make assembly and clamping easier and more effective. The most basic miter joint is made by beveling the mating edges of both parts at 45°, then butting these edges together. Surely the easiest way to make the joint simpler to align is by using biscuits. If you have a biscuit joiner, you know it takes only a minute to set the fence and cut slots in both parts. The biscuits make alignment easy and they offer some reinforcement to the joint as well. Lacking a biscuit joiner, you can achieve the same effect with a through or stopped spline. The details of how to cut a slot and fit a spline were covered in the October 2003 issue (available for sale online at popwood.com), so I won’t repeat that here. Another joint worth learning to master is a routed lock miter joint because it gives the appearance of a miter but introduces an interlock, expands the glue area and makes assembly and clamping foolproof. We’ll come back to that in a little while. Sawing the Bevels Accurate 45° bevels on the mating parts are essential for the case miter. You could cut the bevels using a radial-arm saw, compound-miter saw or sliding compound-miter saw. But the capacity of the latter two saws is limited, typically less than 12”, and all three saws can have some accuracy shortcomings. You’ll most likely want to cut the bevels on a table saw. Tilt the blade to 45° and, depending on the proportions of your workpiece, guide the work through the saw with the miter gauge or along the rip fence. It’s pretty cut and dry, until you run into one (or more) of the problems that often come up. First of all, be wary of kickback. If you’re using the rip fence, you always want the saw blade to tilt away from it. With the blade tilted toward the fence, the offcut is trapped between the blade and the fence, and it’s all but certain to fire back toward you. If you have a left-tilt saw, the cus-

Kerf in backup strip

A backup strip attached to the miter gauge aids when you are trying to locate the bevel cut. Align your layout line with the kerf in the strip. A sure way to assemble case miters is with shopmade miter-clamping cauls. Clamp a caul to each half of the joint, then apply clamps. Do one joint at a time.

Cauls

tomary fence location (to the right of the blade) is the safe one for bevels. But most saws are right-tilters, and with those saws the fence will have to be moved to the left of the blade. In any event, be sure you stand to the left of the blade, clear of “Kickback Alley.” The most disheartening problem is the one that isn’t evident until all the joints are cut and you start assembling them. This is when you discover that the bevel angle is off a degree or two, and the joints aren’t square. Maybe you didn’t tilt the blade enough, but more likely the fault is hiding in the adjustment and alignment of the saw. You should know if you can trust the scale on your saw when you tilt the

blade for this cut. If you aren’t absolutely certain it is accurate, use a drafting triangle to check the blade’s angle. Crank the blade to its maximum height, tilt it, then check it. Make sure the triangle is flat against the saw blade’s body and not against a carbide tip. Double-check the angle by making a pair of test cuts and join the two samples. If the corner they form is square, your setup is right and you can proceed. You won’t always use the rip fence. If the edge being beveled is the short one, you’ll want to use the miter gauge. This common accessory is, of course, another source of inaccuracies. If you use your miter gauge, make sure you square it to the blade with a drafting triangle before T H E CA S E F O R CA S E M I T E R S

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tilting the blade. Instead of a miter gauge, a lot of us use a crosscut sled to ensure we get square cuts. The sled can be used for bevels, too. If you make a lot of bevel cuts and think it’s worth the materials and shop time, you can make a sled exclusively for bevel cuts. If you do this, you’ll derive a couple of benefits. One is the unmistakable angled kerf you can use to align the workpiece. Another is the zero-clearance around the kerf, which helps minimize chipping on the underside of the workpiece. If you work with veneered or melamine-coated sheets, this is a benefit you’ll really appreciate. Finally, if you are using a contractor’s saw, you may be reluctant to tilt the blade at all. Doing that can throw some saws out of alignment. Instead of tilting the blade, you can use an angle sled to deliver the work to the blade. In this case, the workpiece is tilted instead of the blade. Aligning the work for the cut is less straightforward than you might think. If you’re using the crosscut sled or a miter gauge with a backup strip, you have a kerf to use. But there’s no practical way to mea-

POSITIONING A RIP FENCE FOR BEVEL CUTS

Left-tilt saw

Cut chip-free at top surface

Slender offcut may jam and/or kick back

Offcut not trapped

Chipping usually occurs on bottom surface

Tip solidly contacts fence

WRONG

CORRECT

CORRECT

WRONG

Right-tilt saw

Trapped offcut is kickback hazard

WRONG WRONG

Tip can ride under fence, stalling cut, precipitating kickback

Chipping usually occurs on bottom surface

Cut chip-free at top surface

Offcut not trapped Move fence to left of blade

WRONG

CORRECT

WRONG

sure directly from the tilted blade to position the fence. Instead, you have to lay out the bevel cut on the stock and align the layout line with the blade. Then bring the fence into position. It’s easy to do this with your stock on the outfeed side of the blade.

Tip solidly contacts fence

CORRECT

Assembly The biggest problem you will confront when assembling a case miter is applying clamp pressure without forcing the joints out of alignment. V-blocks, lined with packing tape to shed glue, can hold the tips of the bevels together, but other strategies work, too.

SETTING UP A LOCK MITER BIT Midpoint of profile

Centerline of stock Workpiece

Tabletop

Need to raise bit

1. Set bit height, aligning midpoint of the profile with the centerline of stock Workpiece

Need to lower bit

Fence Bottom edge of profile

2. Set the fence back from the bottom of the profile by the thickness of the working stock

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Bit is perfect

Adjust the lock miter bit up or down based on your test cuts. Halve the sample and fit the resulting two pieces together to see how they fit.

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Half of each lock miter joint is cut with the work flat on the top of the router table. Using a push block helps you hold the workpiece down while you advance it across the bit.

Stand the work on end flat against the fence to rout the other half of the joint. A featherboard keeps the workpiece against the fence, obviating the need for a tall fence facing.

Glue tack often holds a small box together while you position pressure blocks and apply clamps. Or you can use packing tape to hold the parts while you apply the clamps. Tape the outside of the joint before adding glue. With a chest or cabinet, the parts are larger, more cumbersome and less cooperative. In this situation, it may be practical to address one joint at a time. Glue up two joints individually, then wait for the glue to set before combining them into the box or case. Also, adding biscuits or splines to the joint makes it easier to align and hold the pieces in place while you position the blocks and apply the clamps.

Lock Miter Joint The routed lock miter sets off in a very different construction direction. You get that attractive miter-joint appearance, but you use a table-mounted router and a “trick” bit to cut it. When the time comes for assembly, the joint aligns perfectly and you can apply clamps without pressure blocks. The bit’s trick is that one setup suffices for cuts on both pieces you want joined. When you have the bit adjusted spot-on and the fence perfectly positioned, you’re golden. Just lay one panel flat on the tabletop and slide it along the fence to rout it. Stand the mating panel upright against the fence to make the mating cut on it. There are two parts to the setup process: setting the bit height and then setting the fence position. You have to make gross settings of both before cutting anything. Then, through a series of test cuts, you hone in on the optimum settings, first of the bit height, then of the fence position. Here’s how: • Setting the Bit Height: The key is lining up the midpoint of the bit with the center of the stock. The midpoint of the bit is on the very slightly angled edge of the interlock, as shown in the illustration below. The best thing you can do is mark the centerline on a scrap piece of the working stock, set it beside the bit, hunker down and squint across the tabletop to line them up. Maybe you’ll nail the

alignment, but it’ll probably take a test cut and an adjustment (or two) to get it just right. Having set an approximate bit height, move the fence into position to guide your first test cut. I stand a piece of the working stock “behind” the bit and sight along the fence to the bit. My objective is to have the stock aligned with the profile’s bottom edge. Make a test cut with the sample flat on the table. Cut it in half, turn one of the pieces over and join the two. If the faces are flush, the bit setting is perfect. If they are offset, an adjustment is needed, as shown below. Use the depth-bar of a dial caliper to measure the offset between the two test pieces. Raise or lower the bit half the measurement. (Having a good depthadjustment system on your router and table is a boon here.) • Setting the Fence: When cutting the joint, you’re dealing with a 45° bevel. The exposure of the cutting edge above the table and in front of the fence must match the thickness of the working stock. Because the bit is set, it’s no longer a variable. Only the fence position is in play. If the fence is set too far back, a cut will remove too much stock and alter the length or width of the workpiece. If it is too far forward, you won’t get the full miter. You already have a gross setting; now you just need to refine it. To set your fence correctly, cut a scrap piece from the working stock, feeding only a few inches into the cut. • If the tip is square, move the fence back to expose more of the bit. • If the cut is shortening the material, pull the fence forward so that it will be able to house more of the bit. • If the tip comes to an acute angle whose tip is flush with the square, unrouted edge of the stock, the fence position is just right. With the final fence position set, you can proceed to the real workpieces.

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C H A P T ER • 15

Final Word on Dovetails BY FRANK KLAUSZ

The dovetail is an ancient joint widely used in cathedrals, barns and Egyptian furniture. It is the right joint for many items including fine furniture, carcases, drawers and jewelry boxes. They are all dovetailed together. I was only 27 years old when I came to this country in 1968 from my native Hungary. Although I had a piece of paper that said “master cabinetmaker,” I was still very eager to learn more about my trade. Where I came from I was happy if I could carry a white-haired master’s tool chest to the job site because I knew I would learn a thing or two that day working with him. Now I am that whitehaired master with 45 years of experience in the trade. In the early 1970s I went to a lot of seminars. Some were on dovetailing with well-known teachers in the woodworking world. Some cut the tails first; others cut the pins first. They used tools that I didn’t own, such as a dovetail marker. They measured the size of the pins and tails, which is completely different from my method. The more I studied, the more confused I became. I decided to find the best way to cut tight dovetails quickly.

A Search for the Best Method I owned an antique restoration shop. I had a chance to study a lot of antiques from around the world. Each time a piece of furniture came to the shop, the first thing I looked at was the dovetails. I studied hundreds of them and made tracings of dozens of unusual pieces. I 84

tried to find an answer for my methods. I learned in Hungary, I worked in Vienna, and I was looking for someone from a different part of the world than Eastern Europe to do dovetails. I found Hector, from Guatemala, a master cabinetmaker. “This is great, Central America!” I said. I asked him to make me dovetails. He said, “You cabinetmaker, you make dovetail.” We had a language problem. I had a hard time explaining to him my intentions. I replied, “I know how to cut dovetails, I want to see how you do it.” “OK,” he said. He grabbed some chisels, a dovetail saw, a marking gauge, some scrap wood, set up the marking gauge to the thickness of the wood, marked the wood, clamped it into a vise and started cutting. He cut the pins, chiseled the pins; from the pins he marked the tails, chiseled the tails and put it together. “How is that?” he asked. I was as happy as can be! “That is exactly the way I do it,” I replied. After my experience with Hector, and my 10 years of researching dovetail techniques, I came to the conclusion that Grandpa wasn’t a bad craftsman at all and my father taught me well. Later on, I wrote some articles for different magazines and I made some videos – one of them is “Dovetail a Drawer with Frank Klausz.” Before I knew it, I was teaching the craft throughout America. I taught hundreds of people how to dovetail. A lesson took plus or minus one hour with a 99 percent student success rate (let’s face it, some of us are born with two left hands).

Anyone Can Do It If you already know how to do dovetails, and are happy with your method, I am happy for you and don’t mean to change your ways. If you are a beginner or learning about new methods, you can do it my way. I know you can do it! How do you know how to write? You learned in school. You made a whole row of a’s. You made a whole row of b’s. Before you knew it, you were writing words and sentences. That’s how I learned to do dovetails. In school, I cut a whole row of straight cuts without marking, checked it often with a square, and improved the next row. In the next lesson, I cut angles approximately 10° to 15°, all to the left, the next row all to the right, and before I knew it, I was cutting dovetails. Companies sell router bits from 7° to 18°, so the angle you use is a personal choice. The strongest dovetails have equal-sized pins and tails, like machinemade drawers. Pope John Paul II’s coffin had approximately 3” pins and 3” tails. The choices are endless. Cutting Dovetails My Way So how do you make dovetails my way? Make yourself a cheat sheet (see the drawing above) or look at some dovetails to copy. Get some scrap wood. Mill them to the same size: 31⁄ 2” to 4” wide, 1⁄ 2” thick and cut them 5” to 6” long. Mill five, 10 pieces, whatever it takes. Set up your marking gauge exactly to the thickness of the wood. Mark the face of the wood. Clamp it into your bench vise, and start cutting with your dovetail saw.

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â–

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Cut Dovetails Easily on Bigger Boards

Illustration by Matt Bantly

When cutting dovetails on a wider board, use the same method as I describe in this article. You have to divide the remaining space after your third cut in half and half again, or 1 ⁄3. With practice it will come naturally. The thicker the wood, the bigger the pins and tails. For example, a 1"-thick board for a blanket chest should have 1" to 11 ⁄2" tails. It both looks good and is very strong. When I was an apprentice watching my father work, I asked him, “How can you do this so fast?” He replied, “Don’t worry, after 10 to 15 years you will be a good beginner yourself.” – FK

(I hope you already practiced your rows of straight and angled cuts.) Every dovetail starts with a half pin. On the other side is another half pin. Cut them. Next to the half pin you need a full tail. Cut it. Cut the remaining distance in half with the same angle, turn it around, make two more cuts and you’re done. Cut only pins, and cut as many as you need until you are pleased. There’s no marking involved – use your eyesight and judgment, and use the thickness of the wood for the width of the tails by judging distances. Make them to your liking. My pins are a little smaller than the tails. That’s the way I like them. You may make them the same way or you may make small pins such as ones found in English furniture. They are all good. You are cutting hand-cut dovetails; there should be some variation. Hand-cut dovetails have character and Mrs. Jones likes that. Once you’re happy with your pins, chisel the pins. Put the chisel on the marking gauge line and tap it. Take out a 86

little “V” cut. Now chisel deeper, taking out chips. Undercut just a very little. Flip the piece over and do the same on the other side. Next, use your pins to make the tails. Hold all three sides even with the edge and the end. With a sharp pencil, mark it from the inside. Here is the hard part: When you cut the pins a little this way or a little that way, it doesn’t matter because you’re making a template. But when you cut the tails, you have to be accurate and cut that pencil line in half. To understand which side of the pencil line you are cutting, you have to mark the half pins and pins with an “X.” That will be your waste. When you chisel out your waste, the “X” will become sawdust and chips. Cut off your half pins; chisel your tails (you are chiseling out the space for the pins). Here comes the fun part: Try fitting it together. If it doesn’t fit, try to find out why, but don’t fix it. Cut your next piece. You may have to go closer to the line if it is too tight or leave more of the line on

to make it tighter. Make a new one using the same pins until you are happy with a snug fit. You are ready to make a jewelry box for your mother-in-law. Good luck trying, I am sure you can do it! Happy woodworking.

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Cutting Dovetails the Klausz Way

1 Set up the marking gauge exactly to the thickness of the wood.

2

3

Next, mark the wood.

Cut a half pin.

4

6

Cut a tail.

Cut another half pin.

7

Go back to your first angle and cut another pin.

5

Divide the distance in half between the two saw kerfs and cut it.

8

Cut one more pin. You’re done cutting pins.

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9 Put the chisel into the marking gauge line and tap it.

10

11

Do the same on all the tails.

Tilt the chisel forward to take out a little piece.

13

14

With a smaller chisel, chisel into the corners. Chisel about halfway.

Flip your stock and chisel from the other side.

15

16

From the pins, mark the tails. Hold the pin board flush on the outside and on the edges.

Mark your waste (the bits of wood you will be cutting out) with an “X.”

12 Put the chisel back up and tap it more. Undercut a little bit, approximately 2°.

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17

18

Line up your saw with the pencil line. Use your thumb for a guide and cut on the “X” side.

19 Cut off the half pin. The saw kerf should be outside of the marking gauge line.

20 Chisel the tails the same way you chiseled the pins.

Here you can see what it looks like to leave the lines on the tails.

21 With the edge of your chisel, push out your waste.

22

23

If you did everything right, it should easily tap together.

Here you can see the finished practice piece.

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Pallbearers carry Pope John Paul II’s cypress, dovetailed coffin into the Basilica during his funeral in the center of St. Peter’s Square at the Vatican April 8, 2005. Note the coffin’s large pins and tails.

to provide information about Vatican woodshops. Brian Boggs, a chairmaker in Berea, Ky., provided contact information for Thom Price, a gondola maker in Venice who didn’t respond. But Mark Marsay, a London, Englandbased refinisher and tool restorer with family in Italy recalled hearing that the coffin was made by Vatican Museums’ restorers and conservators. He also didn’t think it was a solo effort. But he couldn’t confirm anything. Our quest ended when we called Vatican Museums: Our deadline had approached and no one on the other line spoke English. Although much remains unknown, we did uncover some interesting facts and suspicions: • The cypress coffin was adorned with a carving of a cross and the letter “M,” which stood for “Mary, the mother of Jesus.” • Along with the pope’s body a sealed lead tube called a rogito containing a sack of bronze and silver Vatican medals, and a brief biography written in Latin were placed in the coffin. • The pope was buried in three coffins. The innermost cypress coffin was placed inside a zinc coffin, which was placed inside another wood coffin (some sources say the wood is elm; others say it’s walnut or oak). • Charles Garnette, an Indiana-based woodworker who plans to build a replica of the cypress coffin, surmised from pictures that the wood is about 1” thick. Garnette says there

is speculation by Vatican historians that the cypress was recycled wood, perhaps old door planks. He also believes the coffin actually was built in 1981, when Pope John Paul was shot. Still, it’s too bad we don’t know who built the coffin. Such skill and dovetail methodology deserve recognition and exploration. – Kara Gebhart Uhl

AP/Wide World Photos

The morning after Pope John Paul II’s funeral, John Darrow, Frank Klausz’s finisher, asked Klausz, “Did you see the pope’s coffin?” Klausz hadn’t. “It has big, big pins and tails, just like you do them!” Darrow said. Using pictures of the coffin to determine scale, Klausz made a replica pine corner. Then he examined the joinery in the pictures using a magnifying loop. “It was easy to tell nobody measured or used angle gauges,” Klausz says. Finding out who built the highly publicized coffin should have been easy, but it wasn’t. The quest first led to the editor of the Catholic magazine America. He said to contact the United States Conference of Catholic Bishops who said to contact the Vatican Embassy in Washington D.C. who said to contact the Vatican press office who said they don’t handle requests “for such small details.” Several other publications and an organizer of a funeral fair in Poland didn’t respond. Several Vatican experts did research for us and found nothing. The Catholic News Service also couldn’t provide detailed information. Two experts who were in Rome asked several people in the city but no one knew anything. Rev. Steven M. Avella said Archbishop Stanislaw Dziwisz, “the pope’s dear friend and personal secretary” knows but doesn’t respond to these types of requests. Wendy J. Reardon, author of “The Deaths of the Popes” (McFarland & Co.) and part-time teacher of exotic dancing (yes, exotic dancing) suggested contacting Alan Howard who runs St. Peter’s Basilica’s web site. “He’s got some powerful friends in St. Peter’s, so perhaps he can ask them,” Reardon said. Howard gave us the address of Archbishop Piero Marini, who planned the pope’s funeral. John-Peter Pham, author of “Heirs of the Fisherman: Behind the Scenes of Papal Death and Succession” (Oxford University Press) also suggested we contact Marini. So we sent a letter to Vatican City. Surprisingly Marini sent a letter back. After translating its few sentences we learned this: The coffin was built in Vatican City. While this news was welcome, the lack of further information was unfortunate. So the quest took some alternate paths. Travel writer Rick Steve’s consulting department was unable

AP/Wide World Photos

Dovetails, The Pope’s Coffin, and the Unidentified Craftsman

Pope John Paul II’s outermost coffin is taken to the grottos beneath St. Peter’s Basilica at the Vatican.

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C H A P T E R • 16

Half-Blind Dovetails by Jig Dovetails are prime joints. Long history, great appearance and cachet. Used in boxes, drawers and carcases. But for many woodworkers, cutting dovetails the traditional way – with saw and chisels – is an insurmountable challenge. If you aren’t ready to tackle handcut dovetails, there are plenty of router accessories on the market to help. There are so many in fact, and they have so many variations in setup and operation, that I’m going to narrow my focus to the most common: the half-blind dovetail jig. The typical half-blind dovetail jig consists of a metal base with two clamping bars to hold the workpieces. A comb-like template rests on the top to guide the router in cutting both pieces at once. The appropriate bit and bushing are packaged with the jig. Usually you use a 1⁄ 2”, 14° dovetail bit and a 7⁄ 16” guide bushing to make the cuts. Use any router, which is to say, the one you have. I typically use a 2-horsepower fixed-base model. The ability to plunge is irrelevant, and plunge routers generally are awkward for work on the edge owing to their high centers of gravity. Brute power doesn’t contribute anything. When the urge to rout half-blind dovetails seizes you, get out your jig and clamp it at the edge of your workbench. Presumably, you’ll have stored the instructions and the right bit and guide bushing with the jig. Select your materials and make sure all like parts are jointed and planed uniformly. Not all the parts must be the same thickness. The fronts can be 3⁄4”

Photos by the author

BY FRANK KLAUSZ

Dovetail jigs can produce excellent results in a short amount of time. The key is knowing how to adjust the jig to achieve a perfect fit.

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thick, and the sides and backs 1⁄2” thick, for example. Or 3⁄ 4” and 5⁄8”. Everything can be 11⁄16”. Just be certain the fronts are consistently sized, the sides are consistently sized, and so too the backs.

Set Up the Router Install the guide bushing. (If you have a centering mandrel, use it to center the bushing to the bit’s axis.) Adjust the router so the collet is relatively close to the bushing. Carefully insert the dovetail bit through the bushing and into the collet. Tighten the collet nut. Adjust the depth of cut next, as shown on the facing page. When you do this, turn the bit slowly by hand to absolutely ensure that the bit doesn’t contact the bushing. The cutting end of the bit is too large to pass through the bushing. If you use a steel bushing, it will damage the bit’s carbide, so you want to avoid accidental contact.

Check your jig’s instruction for the recommended depth-of-cut setting. It’s often in the 21⁄32” to 23⁄32” range, depending upon the thickness of the template. A good generic starting point is 3⁄8” plus the template thickness (to get an accurate measurement of the template, use dial calipers).

Clamp the Work in the Jig The work has to be clamped in the jig in a particular way. When you cut following the template, tails are formed on the front board in the jig, and sockets into which the tails nest are cut simultaneously into the top board. So the socket piece – and that’s always the drawer front or back – is on top. The tail piece – the drawer side – is at the front. Alignment is critical: The tail board overlaps the end of the socket board, and its end must be flush with the upper face of the socket board. The

boards must be perpendicular to each other. In addition, the tail board is offset. Both boards are clamped in the jig with their “inside” faces out. Here’s an easy way to do it. Roughly position the tail piece in the jig, with its top end well above the jig. Slip the socket piece under the top clamping bar, and butt it tightly against the tail piece. Clamp it firmly. Now loosen the clamp holding the tail piece and lower it until its end is flush with the other workpiece. Clamp it firmly. Both pieces need to be against the alignment pins or stops. These pins align the parts so they are offset exactly 7⁄16”, which is half the center-to-center spacing of standard router-cut half-blind dovetails (7⁄8”). Every jig has these pins on the right and on the left. Use those on the left for now. The template must rest flat on the work. Its fore-and-aft alignment is criti-

In setting the depth of cut, you must account for the template thickness as well as the cut itself. Use a small machinist’s square to set the bit extension from the baseplate.

Line up the workpieces carefully as you clamp them in the jig. Snug the end of the socket piece (it’s on top) against the inner face of the tail piece (it’s on the front). Make sure the pieces are flush against the guide pins or stops. (The pin on the jig is hidden by the socket board and clamping bar.)

92

Chipping along the shoulder of the tail piece is a problem. To eliminate this, make a shallow scoring cut across the tail piece first. A climb cut – where you feed the router from right to left – is most effective here. Just be sure the router doesn’t get away from you.

Move the router along the template, feeding the router into each slot and keeping the guide tight against the template as you come out of one slot and round the finger into the next slot. Any little bump on either tail or socket will prevent assembly of the joint.

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cal to the fit of the joint, but don’t worry about it for now. Use the out-of-the-box setting for your initial test cuts, and adjust as necessary.

Cut a Test Joint Rest the router on the template with its bit clear of the work. Switch on the router, and make a quick, shallow scoring cut across the tail piece, feeding from right to left (yes, this is a climb cut). The purpose of this cut is to prevent tear-out along what will be the inside shoulder. What often happens is that the bit blows out splinters as it emerges from each slot of the jig’s template. If there’s no shoulder established first, these splinters can run down the face of the drawer side, defacing it. Now rout the dovetails, slot by slot, beginning on the left and working to the right. Feed the router into each slot of the template, then back it out. Keep the router firmly against the template as you round the tip of each template finger; you want to completely form each tail – no little lumps. I usually zip back through the slots after the first pass, just to be sure I didn’t pull out of a slot too soon, leaving that socket only partially cut. Don’t just lift the router from the template. The bit will ruin both the cut and the template. Instead, turn off the power and pull the router toward you, getting it well clear of the jig before lifting it. Take a good look at the work and be sure you haven’t missed a spot. If you have, re-rout it before moving anything clamped in the jig. Remove the template, unclamp the work, and test assemble the joint. Fine-tune the Setup Slip the test pieces together. Maybe something’s not quite right. Perhaps the fit is too loose. Or too tight. Or the sockets aren’t deep enough. Or the parts are a little offset. All of these ills are cured with some fine-tuning. The bit’s cut depth is the primary control of fit. The way it works is shown in the drawing, “Setting Depth of Cut,” above. The cut – the socket – is always the size of the cutter. But when you alter

the depth of the cut, the width of the material left between sockets changes. Because you are cutting both tails and sockets at the same time, the material between the sockets is in fact the tail. In practice, this aspect of the setup is at the same time deceptive and frustrating. The transition from “no fit” to “perfect fit” is abrupt – just a 1⁄32” change can make all the difference. What often happens is that you lose confidence in the adjustment regimen after one or two incremental changes with no apparent effect. “Well, this isn’t getting me anywhere!” you think, and start adjusting in the other direction. And you seesaw between increasing and decreasing the cut depth, never hit the right setting, get totally frustrated, and shelve the jig, never to use it again. Take heart. Remember that woodworkers have been using these jigs for decades, and that routers have been pretty primitive tools for most of that time. You can do it. Be patient, methodical and persistent. Here’s what you do: • Reduce the cut depth to loosen the fit. • Increase cut depth to tighten the fit. Once the depth of cut is dead on, analyze a new test cut and determine if other adjustments are needed. The relationship of the joint surfaces is controlled by the template’s fore-andaft position. Ideally, the surfaces are flush when the joint is seated tightly. • If the side is recessed, the pin is short and the socket is long. Shift the template back. • If the side is proud of the front’s end, the pin is long and the socket is short. Shift the template forward. Your jig’s instruction sheet should explain exactly how to accomplish this. Generally, the template bracket sets against a nut on the mounting stud. Turn the nut and the template moves. These studs usually are 1⁄4”-20 bolts, so a full turn of the nut will move the template in or out 50 thousandths of an inch. Look at the edges next. When the joint is assembled, the adjoining edges should be flush. If they aren’t, you may not have had the workpieces snug

Setting Depth of Cut 





OPTIMUM: Pin formed matches slot cut by dovetail bit. 





TOO DEEP: Pin formed is wider than slot.







TOO SHALLOW: Pin formed is narrower than slot.

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whether you’re dovetailing one drawer or 50. A good way to avoid confusion is to label the parts on what will be their inside faces, as shown in the drawing “Organizing the Parts� at left. Where you put the labels is as important as what they are. The letters are always associated with a particular part. Put the letter at the bottom so you know which edge goes against the alignment pins. On the jig itself, mark the two-letter combinations beside each pair of alignment pins, as indicated in the drawing. As you clamp the parts into the jig, orient the letters toward the pins, and check the combination. If it isn’t on your list of two, you are at the wrong end of the jig.

against the alignment pins. Or the pins may be slightly misadjusted. Any other problems you have will have stemmed from misalignment of the workpieces in the jig. Make sure the top surface of the socket piece is flush with the top end of the tail piece, that they are at right angles to each other, that the template is square to the workpieces, and so forth. When you’ve successfully fine-tuned the setup using the alignment pins on the left, cut a test joint at the other end of the jig. Do any additional tuning needed there.

Dovetailing the Good Wood Before starting on the actual project parts, make sure you’re organized. The parts are worked “inside out.� If you are doing drawers, the sides always go on the front of the jig, and the fronts and backs always go on the top. Some joints are cut on the right side of the jig, others on the left. It’s easy to get mixed up,

Keep the pieces organized by marking the parts of the drawers as shown in the drawing above. Mark your jig with the letter combinations that are shown on each side of the dovetail jig.

CBDL

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ORGANIZING THE PARTS

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C H A P T E R • 17

Impossitails BY ROY UNDERHILL

Start with two pieces of contrasting stock, truly square and equally thick all about. Mark the length of the dovetails (perhaps three-quarters of the thickness) around the ends of both pieces with a marking gauge fenced against the end grain. Lay out dovetails on each face, ensuring that they are identical by working your way around with a marking gauge, coming in from both edges to mark the wide ends of the dovetails. Then reset the gauge to mark all the narrow ends. QUADRATAIL LAYOUT.

IS IT MAGIC? Until their secrets are revealed, the mysteries of the “quadratail” and “rising dovetail” are enough to make anyone melancholy!

An ordinary day in the shop, but suddenly, you’re dovetailing through another dimension, a dimension not only of sight and sound, but of mind. You’re on a journey into a woodworking land whose boundaries are that of imagination. That’s the signpost up ahead, your next stop … The “Impossitails” Zone! In the ordinary world, we accept the limitations of dovetails. They’re strong in most directions, but no matter how tight you cut them, they always have one plane of weakness – they can pull apart in the same direction that they were put together. That’s why, starting in

the times of Dante and de Sade, certain deviant minds of woodworking began the quest for dovetails that interlock for eternity, configured so that the joint confronts solid wood in every direction. The dovetails they created can never come apart. Problem is, they can also never go together. Or so it seems. Welcome to the world of impossitails – joints that exploit our tendency to think at right angles to create the illusion of impossibility. We’ll look at two of these joints, the quadratail and the rising dovetail – unlocking their secrets with the key of imagination.

The ‘Quadratail’ … is a sliding dovetail scarf joint that connects two lengths of square stock with dovetails showing on all four faces. Now, a dovetail emerging on two opposing faces would make sense; you could just slide them together. But four? Our mind connects the dovetails through the joint at right angles to the four surfaces, forming a mental interior in the shape of a plus sign – impossible to slide together, but there it is! I M P O S S I TA I L S

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CHEEKS AND SHOULDERS. Saw

the cheeks and shoulders of the dovetail tenon. Cut the mortise by making three saw cuts, two down the sides and one down the middle then chisel out the waste. Trim as necessary and slide them together.

QUADRATAIL CUTS. Scribe

the diagonal lines connecting adjacent dovetails across the end grain of both pieces. Mark the waste pieces accordingly and saw the cheeks of the tails and sockets. A fine saw running right down the layout lines should give you the right amount of clearance. You can easily saw the shoulders off the outside of the dovetailed piece, but the space between them and in the sockets on the other piece will need roughing in with a coping saw. Finish the end grain with your sharpest chisel.

The trick is that the dovetails connect obliquely through adjacent corners rather than directly across. Because the diagonal paths of the two sliding dovetails are parallel, the joint easily slides together and apart, but only at 45° to the faces.

GAUGE THE RISING DOVETAIL. Superimpose

the two pieces just as they would intersect if pushed squarely together into a T. Lay out the width of each piece on the other and bring the lines all around. Starting on the piece that you will tenon, gauge down half of the thickness on the end grain. Mark that end, then, with the same setting, mark along the far side of the piece to be mortised.

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Creating the illusion calls for precise saw and chisel work, but it’s easy enough. Simply draw equal dovetails on all four faces then saw and chisel them out on the diagonal. One becomes the positive and the other negative space – one the dovetail and one the socket.

The Rising Dovetail … is even more irritating, and far easier to cut than to explain. Here, you create the dovetail illusion by exposing an oblique slice of a triangular prism. It’s called the rising dovetail because the tenon slides upward in the mortise to fill the exposed dovetail-shaped space. This is the trick behind the notorious puzzle mallets from the turn of the last century. This is not a particularly strong joint when used in equally-sized stock. The only place I have seen the ris-

CONVERGENT LINES. Set your bevel gauge to a bold angle and draw two sets of convergent lines on the edges of the piece to be mortised – two lines beginning at the ends of the “half-of-the-thickness” line and two lines on the opposite edge beginning at the bottom. Connect the ends of these lines across the face (above) and you’ve defined the mortise. (You can see the layout of the backside of the mortise reflected in the face of the dovetail saw.)

ing dovetail used in furniture is in the teacher’s lectern in a little schoolhouse at a Colonial Virginia plantation. The T-shaped foot of the lectern that faces the students was joined with a rising dovetail, posing a perpetual question and the lesson that things are not always as we suppose them to be! Some of the old books advise you to glue these impossitails together “so that the secret may not be discovered.” I’d leave them loose so that others can enjoy the mystery. It just depends upon how irksome you want to be.

TRANSFER MARKS. Set this piece edgewise on the face of the tenon and transfer the dimensions. Connect the dots and you have defined the dovetail tenon.

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C H A P T ER • 18

Power-Assisted Dovetails BY SCOTT GIBSON

Photos by the author

It’s hard to blame anyone for turning to a router and template when the job calls for a kitchen’s worth of dovetailed drawers. If nothing else, the process is fast. Once you’ve fine-tuned the router settings, you can knock out a lot of drawer boxes quickly and with perfect regularity. And that’s the problem – all that regularity makes for boring joinery. Boring and uniform: With many dovetail jigs, the spacing of tails and pins is fixed, and those pin-to-pin dimensions don’t always coincide with actual drawer heights. Templates that allow adjustable spacing are an improvement, but pin width and slope are fixed by the shape of the router bit, and bits may have thicker profiles than you would like. These characteristics aren’t as important when the drawers are going into a kitchen. But when a drawer is bound for something special – a chest of drawers, for example, or a nice little side table – the look and lack of flexibility in a machine-cut dovetail is all wrong. Handcut dovetails have a lot more eye appeal, and their dimensions and spacing can be infinitely adjusted to suit different tastes, species of wood and drawer heights. The only problem is that cutting them by hand and removing all the waste with a chisel and mallet is tedious – about as interesting as watering the lawn. One way to speed up the process, without detracting in any way from the hand-cut look, is to use a small router to do a lot of the heavy stock removal. I use a laminate trimmer, a small router that can be guided easily with one hand. This P O W E R -A S S I ST E D D OV E TA I L S

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Half-blind dovetails cut using this method look exactly like those cut entirely by hand.

Using a marking gauge, scribe a line across the end grain of the drawer front. It should be about one-third of the board’s thickness in from the face.

Without changing the setting on the gauge, scribe a line on both inside and outside faces of the drawer sides. These are the base lines for cutting the tails.

approach takes half the time of doing all the work by hand, and with a little practice produces consistently accurate results. Best of all, you won’t be limited by a template or the shape of a router bit. It’s really the best of both worlds.

seasonal changes in moisture content won’t swell the drawer closed in summer heat and humidity. The drawer sides and the drawer front must be cut dead-on square for everything to work correctly. With stock prepared, lay out the joint just as you would if no machine were involved. I start by using a marking gauge to strike a line on both ends of the drawer front about a third of the drawer’s thickness in from the front . Without changing the setting, strike a line across each drawer side. This represents the length of the dovetails, and while both dimensions must be equal, the exact length isn’t important. Leaving a narrower margin at the front of the drawer looks a little more graceful to me, but it also increases the risk slightly that something will go awry later in the process. With these lines scribed, change the setting on the gauge so it equals the thickness of the drawer side and mark

Lay Out & Cut the Tails First Much of the process is identical to doing it all by hand, and the first thing is to prepare the drawer parts carefully. Assuming the drawer is to fit in a case, without the use of any drawer hardware, an accurate fit is essential if the drawer is to work smoothly. It may seem counter-intuitive, but making a drawer loose for the opening makes it harder to operate because the drawer racks and binds as it’s opened and closed. The drawer front should just fit into the opening side-to-side. Be sure to allow enough clearance in height so that 98

the inside surface of the drawer front. This represents the length of the pins and I try to get it as close to the actual drawer side thickness as possible. Here’s why: In case work, it’s more common to lay out the joint so that the pins will protrude slightly when the piece is assembled. They can be belt-sanded or planed flush with case sides very easily. But taking too much stock off a drawer side after the joint has been glued up will ruin the fit. With lines scribed, set an adjustable bevel for the angle of the tails. By convention, the slope on the sides of the dovetail is 1:6 for softwoods and 1:8 in hardwoods, although I’m not sure it matters that much. Lay out the tail spacing of the tails along the drawer side with a pencil. Spacing is entirely up to you, although it’s typical to start and end the layout with a half-pin. It also saves time to use a chisel to set the width of the tail at its widest point. Now cut out the tails on the drawer sides with a saw all the way to (but not beyond) the scribed base line. Split the line to the waste side, as furniture maker and author Tage Frid used to say, and you won’t go wrong. The half-pin waste on each end can be removed with just a saw. The waste between tails can be chopped out with a chisel. Work from both sides, and when you’re finished make sure all the waste has been removed from the inside corners of the tails. Use a chisel or knife to clean out what’s left. Because tails are cut first, it doesn’t matter that much if the angle of the cut is slightly off, or if one tail is slightly wider than another. What does matter, however, is getting the saw cuts square to the end of the drawer sides. If those cuts are angled, it won’t be possible to transfer the pin layouts accurately to the drawer front, and the joint won’t fit properly. Inspect the cuts carefully, and if they’re not square, true them up with a chisel before going ahead.

Use Tails to Lay Out Pins The completed tails are used to lay out the pins on the drawer front. I put the

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Reset the gauge so it equals the thickness of the drawer side and scribe a line across the inside face of the drawer front. This represents the depth of the dovetail pins.

Using a chisel to mark out the tails saves time. Just align the center of the chisel on a mark representing the center of each tail and mark the edges. Then use the bevel to draw the tail locations.

Cut out the tails on the drawer sides with a dovetail saw, taking care not to go past the scribed base line. Unless the cuts are square across the edge of the board it will be impossible to transfer your pin locations accurately to the drawer front.

Use a mallet to chop downward at the base line, then pop out a sliver of waste by working in from the edge of the board. Take it a little bit at a time and work about halfway through the board. Then flip the board over and finish from the other side.

Dovetail spacing is completely flexible, although the layout usually begins and ends with a half-pin. You can make a small “x” where waste is to be removed.

With the sides of the tails defined by the saw kerfs, use the chisel to chop out the waste. It helps to make the scribe line a little deeper with a knife and pare a small shoulder with a chisel. This prevents the chisel from drifting over the scribe line as you chop.

drawer front in a bench vise and arrange the drawer side so the front edge lines up exactly on the scribed line on the drawer front. Hold the drawer side firmly and use a sharp layout knife to trace the pins on the end of the drawer front. Make sure the drawer side doesn’t shift out of position as you work. This would normally be the time to cut to the lines with a saw and chop out the waste with a chisel, and here’s where you’ll bless the person who invented the laminate trimmer. What makes it ideal for half-blind dovetails is its small size and light weight, and the fact that it can be guided with one hand. I use a 1⁄4” solid carbide spiral

up-cut bit, which makes a very clean cut. When all the lines have been transferred to the drawer front, clamp a piece of straight wood to the front side of the drawer front to give the router base a wider contact surface. A piece of material 3⁄4” to 1” thick is usually adequate, and it should be clamped so it’s perfectly level with the edge of the drawer front. Adjust the bit depth so it meets the scribed line on the inside of the drawer front as shown on page 76, turn on the router and nibble out the waste between pins. If you’re careful, the bit can be brought surprisingly close to the scribed pin lines – less than 1⁄ 16”. Work slowly, P O W E R -A S S I ST E D D OV E TA I L S

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Check that the tails are clean all the way through, with no remaining waste in the corners. It’s also a good idea to check that the cuts are square across the end of the board – if not, correct the problem now by paring the tails with a chisel.

Now transfer the tail layout to the edge of the drawer front by aligning the drawer side on the scribed line on the drawer front and marking the pins with a knife.

Clamp the drawer front at a comfortable working height, with the inside of the drawer facing you. To help stabilize the laminate trimmer, clamp a scrap of wood to the drawer front. Make sure the clamps are set below the base line.

be mindful of the direction the bit is spinning and keep an eye on the back line as well as the pin line. The bit will leave rounded corners, but it will remove almost all of the waste.

Clean Up the Cuts and Assemble the Joint Once the router has finished its work, what you should be looking at is a nearly complete joint. All that remains is to pare away the little bit of remaining 1 00

Holding the drawer side firmly, use a layout knife to scribe lines on the edge of the drawer front. These lines mark the dovetail pins.

Adjust the base of the router so the end of the bit just touches the base line. This carbide spiral bit removes waste cleanly. Turn on the router and nibble out the waste between pin lines. Work slowly and be careful not to drift over your layout lines.

material on the drawer front pins with a sharp chisel. Rather than removing all the waste in one swipe, it’s best to take smaller bites. Simply place the chisel just a bit back from the routed edge and tap it lightly to pare away a sliver of wood. Work up to the scribed line, finally placing the edge of the chisel right in the scribe line (this is why it’s better to use a layout knife rather than a pencil to mark them). A source of raking light will make the lines

easier to see, but you can also darken them in with a pencil. You’ll still be able to feel the edge of the chisel slip into position when you make the last cut. Use the same approach to pare away the waste on the back line, and work carefully into the corner, taking a little bit of material off at a time until the corner is completely cleaned out. One thing to watch for is wild grain – it can send your chisel off in the wrong direction and damage the workpiece. If working

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straight down seems to be causing a problem, try paring in cross-grain from the side. If you do shear off a section of pin (and it happens occasionally), you can always use cyanoacrylate glue and an accelerator to quickly repair the damage. With both pins and tails cut, the joint can be tested for fit. Ideally, it will take light taps of a mallet or small hammer to bring the two pieces together. Getting a good joint is a matter of practice and feel. If the saw cuts are square and the marks transferred accurately to the drawer front, joints made this way should fit together nicely. Start the joint together to check – you can always make a minor adjustment now if something seems too tight – but don’t put the joint all the way together just yet. Once you’re reasonably sure the joint is going to fit together to your liking, add glue to the sides of the pins and assemble your parts. When the glue is dry, trim the joint flush. The result should look handcut because it is hand-cut. You’ve just had an assist from a power tool perfectly suited for the job.

When you’re finished with the router, there should be very little material left to remove.

When the sides of the pins have been pared to the line, work on the front of the joint. Make sure the front edge and the sides of the pins are square, not sloped, so the joint will go together without splitting the drawer front.

Begin paring away the waste on the sides of the pins. Take small bites. Finish each pin by placing the edge of the chisel right in the knife line and tapping lightly with a mallet.

First test the joint by just starting the two pieces together. Pare away any material that would seem to interfere with the joint. Then apply a bit of glue to the sides of the pins and assemble the joint.

You’re done. Parts should fit snugly, but if you find you have a gap between a tail and a pin, a sliver of wood and a touch of glue will work wonders.

P O W E R -A S S I ST E D D OV E TA I L S

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C H A P T E R • 19

Shouldered Sliding Dovetails BY GLEN D. HUEY

One of the defining features of 17thand 18th-century furniture is the dovetailed horizontal case divider. Case dividers are the rails that separate the drawers, or the door and drawer sections. Attaching these dividers to a case’s sides using sliding dovetails is probably the strongest way possible to assemble a carcase. However, reproducing this detail is daunting to many woodworkers. Not only is a sliding dovetail seen as complex joinery, but it can be made in different ways. The basic sliding dovetail, shouldered sliding dovetail and through sliding dovetail (shouldered or not) are just a few of the options. Each type of sliding dovetail requires a different jig. I’ve used a variety of these jigs in my many years of building reproduction furniture. Some jigs capture the router base and are specific to a certain router bit. If you need to use more than one bit (to make a shouldered dovetail, for example) this can be a problem – unless you own two identical routers. Other jigs are as large as the entire case side, making them hard to handle and store. But I’ve found a better way. Using a 3⁄4” top-bearing flush-trimming bit (often used for pattern routing), a 3⁄4” dovetail bit, a template guide with a 3⁄4” outside diameter and a shop-made straightedge, any of these joints can be made easily.

From Dado to Dovetail To understand how this works, let’s start with a simplified version of the joint: a dado. With a straightedge clamped 1 02

across a cabinet side and a flush-trimming bit in your router, you can cut a dado for case dividers or web frames. Simply position the straightedge where you want your dado, set the depth of cut on your router and plow it out. The bearing on the bit follows your straightedge. By using a dovetail bit with a template guide and this same setup, you can use the straightedge to make the basic sliding dovetail shown above left. Use a template guide that has the same outside diameter as your dovetail

bit to make measuring simple. Next, clamp your straightedge exactly where you want the sliding dovetail to go. Set the proper depth for the bit, (9⁄16” 3 in ⁄4” material, for example) then rout the dovetail trench or socket in a little further than the width of the divider. The trench doesn’t need to extend all the way across the side. But because the dovetail trench will have a rounded end, the trench must extend a little further so the square-shouldered tail on the divider will fit.

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Two-step Shouldered Joints A shouldered dovetail is ideal for casework that uses web frames, which support drawers. The straight shoulder, which supports the web frame, is cut just as you would cut a basic dado. First align your straightedge as you did with the basic sliding dovetail. With a 3⁄4”-diameter flush-trimming bit in your router, plow out the dado to 3⁄16” deep. Next, take your router with a template guide and dovetail bit, set it to 9⁄16” deep (without moving the straightedge) and make the cut into the case side. The cut should be a bit longer than the width of your front divider. Thanks to the template guide (and keeping the straightedge in one fixed location), the dovetail portion of this cut is centered in the dado automatically.

the joint (called the tail) on the end of your horizontal divider using the dovetail bit in your router table. The process is explained on the next page. Then use the tail to lay out the location of the socket on the case side. Now you can saw out the socket. Orient the saw to match the two tail sides, then cut in from the front edge the width of the divider. Finally, chisel out the waste between your saw cuts.

Don’t Forget the Tails! To make the mating joinery on the dividers (the tails), I use my router table. Use the same dovetail bit you used to

cut the dovetail sockets to form the tails to ensure that the joint fits well. Set the fence to adjust the size of the tails, cutting on both sides of the divider. I like to sneak up on the final cut to ensure a snug fit. Set the bit to cut at the appropriate height for each joint style. For the basic sliding dovetail, that height should be about two-thirds of the width of the case side. If you’re making a shouldered dovetail, allow for the 3/16” shoulder depth in your layout. The through dovetail is cut with the height of the tail equal to the thickness of the case side (if you are adding

9/16"

Through Sliding Dovetails For an even fancier look, you can create through sliding dovetails. These joints allow the end of the case’s divider to be seen on the outside of the case. Start once again by plowing the dado as explained above. You could cut the socket portion of this joint with a router, but there’s much less chance of tear-out if you cut the socket using a handsaw. If you go with this hand-tool route, you should first cut the male portion of 9/16"

BASIC SLIDING DOVETAIL The simplest option in sliding dovetails. The socket or trench requires only a single pass with the dovetail bit. 3/4"

3/16"

3/16"

SHOULDERED SLIDING DOVETAIL This joint adds a shoulder to the dovetail and requires you to make a first pass with a pattern-making straight bit. Then the dovetail bit (set at the same depth as on the joint above) is used to cut the dovetail.

THROUGH SLIDING DOVETAIL A more complicated joint, this is made in three steps. First the straight bit forms the shoulder, then the dovetail bit shapes the divider pin. The final dovetail socket is hand cut to avoid tear-out.

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a shoulder, remember to allow for the shoulder). Your through dovetail doesn’t need to expose the whole width of the divider. For example, you can show only 3⁄4” on the sides if you like. After cutting the tails on both ends of the divider, use a saw to trim the end 3⁄4” back from the front of the divider on both sides. Then cut from the back of the divider right at the point where the tail begins from the divider to remove the unneeded tail section. Repeat this cut on both ends.

With the back portion of the tail removed, slide the divider into the dado in the case and mark, then cut, the matching socket.

51⁄64”

and 1” if you need thicker drawer dividers. You should consider using sliding dovetails for any number of woodworking tasks. The possibilities are endless.

Whatever Size You Need While these techniques work great with the standard 3⁄4”-thick drawer dividers that are common today, they also work with other thicknesses of dividers by using different-sized template guides and bits. The guides are readily available in a wide variety of sizes, including

The Steps to a Shouldered sliding dovetail Making a shouldered sliding dovetail begins by cutting a dado in the case’s side. This dado is easily made with a pattern-cutting bit and the right jig, which I call a straightedge guide. The bed of my jig, shown below, is simply two pieces of plywood cut slightly longer than the width of the case side, then glued or screwed together face to face. (Depending on your router and bit, you might need only one thickness.) To complete the jig, screw a third block to the underside of the straightedge guide to hook it square against the front edge of the case side. The hook should be sized so you can clamp the jig in place without interfering with the base of the router. As you cut the dado,

make sure you move the router in the correct direction (against the rotation of the bit) to keep it tight against the jig. Next, install a template guide in your handheld router and the dovetail bit. I should mention one important detail: To use a template guide that is the same diameter as the patterncutting bit’s bearing collar (in this case 3 ⁄4"), it will be necessary to attach the guide first, then insert the bit afterward. Because of the identical diameters, the router base can’t be slipped over the bit with the template guide in place. The guide is the same diameter as the collar to allow the dovetail to run exactly down the center of the dado cut.

With the template guide in place and the depth set on the dovetail bit, you’re ready to cut the dovetail socket, as shown below. With the socket created, it’s time to make the mating tail on the end of the drawer divider. Mount the dovetail bit in a router table and run both sides of your divider on end between the fence and bit. You will need to make a few test passes to get the perfect fit. Note that I’m using a push block behind the divider for safety and to stabilize the piece during the cut. — GH

Straightedge guide

Dado

Case side

Front edge hooks over case side

The first step involves plowing out a simple dado with a pattern-cutting bit, shown at right.

1 04

Use a dovetail bit, shown at right, to make your shouldered dovetail socket.

You can easily rout the tail of the joint on your router table with the matching dovetail bit.

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CHAPTER • 20

Sliding Dovetails B Y B I L L H Y LT O N

For the woodworker who builds furniture and cabinets, the sliding dovetail is a joint well worth mastering. It’s strong and versatile, with myriad applications, from case construction to leg-and-rail joinery. I’m sure you’ve seen drawings of the joint. It’s a hybrid of the dado and the dovetail, with a groove in one part and a tongue on the other. Naturally, the tongue fits the groove. But because both the groove walls and the tongue sides are angled like a dovetail, the joint has to be assembled by sliding the tongue into the groove from one end. There are several advantages here:

Assembling a chest with several drawer dividers is simple when the parts lock together. You don’t need five hands and a bunch of clamps. And once the chest is assembled, the joint mechanically resists tension, meaning that the sides can’t bulge outward, separating from the dividers. If left unglued, the sliding dovetail allows wood movement. The obvious example here is a breadboard end, attached across the end of a wide, solidwood panel such as a chest lid or a tabletop, as shown below. The end is intended to keep the panel flat, while allowing it to expand and contract. These are just

Router-cut sliding dovetails link parts together, with or without glue, and they have a multitude of uses.

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EFHCJU

Photos by the author

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Because of the dovetail proďŹ le, you can’t simply lift the bit out of a stopped cut; you have to back it out. To avoid having the router drift away from your fence as you do this, use a twin-fence jig for such cuts. The jig traps the router, and with a stop attached, the router can produce only the dovetail slot you want.

The sliding dovetail is an excellent joint for mounting a breadboard end on a chest lid. The joint is glued only at the front, so seasonal expansion and contraction of the lid panel is visible only at the back. Flush with the end of the breadboard when assembled in mid-winter, this lid panel has expanded markedly during a humid summer.

If you have two routers with the same base diameter, you can use one for the “wasting� cut with a straight bit (as shown at top), and the other with the dovetail bit (above left and right).

two of the many suitable applications. Each sliding dovetail joint requires two operations – cutting the groove and cutting the tail. Both operations are done with the router, and to get a good fit, it’s imperative to use the same bit for both. Grooves can be cut with a hand-held or table-mounted router. The location of the cut and the size of the cut itself usually will dictate which approach is optimum. The tails likewise can be cut either way. The portable router generally requires jigging to steady it on the narrow edge being worked. As a consequence, most woodworkers cut the tails on the router table. There you need nothing beyond all-purpose accessories

such as a push block and a featherboard or two. Choosing a bit: Dovetail bits are made in a variety of diameters and angles. Most half-blind dovetail jigs require a 1⠄2�-diameter, 14° bit on a 1⠄4� shank, so I’d say that’s the most common bit. But thanks to the prevalence of through-dovetail jigs, you can buy bits with 7° tapers, as well as with 71⠄2°, 8°, and 9° tapers. These angles yield more of a hand-cut look. A benefit of these bits – one that’s pertinent here –is that they allow deeper cuts and stronger tails. Check out the comparison drawing below. A 1⠄2�-diameter, 14° bit can’t cut more than 1⠄ 2� deep because, at that point, the bit has tapered to a 1⠄4� diameter. At the same spot on an

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Template guide Template

Scrap

Make the template with some overhang along the front edge, so the template guide is caught in the guide slot while the bit is still clear of the work. A waste strip clamped to the front edge of the work prevents tear-out or chipping. The fuzzies on the work’s surface are common, but are easily removed with sandpaper.

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8° bit, the girth is about 11⁄32”. With this bit you can go 13⁄ 16” deep and still have a 1⁄ 4” width. Scaling the joint: For casework, a shallow sliding dovetail – say 1⁄8” deep – is all you need. Even in a dado joint, that depth is sufficient to withstand the shear stresses applied to a cabinet and its parts. Add the dovetail angle and you reap the mechanical blessings it confers. Plus that cut depth is easy for any router to cut in a single pass. The dovetail groove in a breadboard end, on the other hand, should be as deep as you can make it without compromising the groove-wall thickness or the thickness at the base of the tail.

Slotting a Face Both portable and table-mounted routers can cut the slots. For casework, I use a portable router, guiding it along a clamped-on straightedge. A shopmade T-square is perfect. If you’re cutting a 1⁄8”-deep slot, as I suggested, and using an 8° bit, then cut away. If your cut is deeper, say 3⁄8”, and your bit is a 14° taper with a very narrow waist, it’s a good idea to “stage” the cut. The way to do this is to first rout a groove with a straight bit that matches the dovetail’s waist diameter, cutting about 1⁄ 16” shy of the final depth. In the example situation, you’d use a 1⁄ 4” straight bit, cutting – perhaps in two

Cut a tail on a narrow piece such as a drawer divider by standing it on end, backing it up with a scrap block, and advancing it along the fence. The backup block minimizes exit splintering and helps stabilize the work, reducing its tendency to “walk” along the fence. Make a cut, spin the work 180° and cut again to form the tail.

passes – about 5⁄16” deep. This is most convenient to do if you have two routers of the same base diameter, so you can set one up with the straight bit, the other with the dovetail bit. The fence position for both cuts then ends up being the same. Stopped slots: Because of the dovetail profile, a stopped slot requires you to back the bit out of the cut. There’s a slight risk of it grabbing as you back it out of the cut, because that is a climb cut. That could pull the router off the fence, and it could ruin the cut. For a stopped slot, I prefer to trap the router, either between a pair of fences or with a template. If the router’s trapped, it can’t wander, regardless of the feed direction. Cobbling together a twin-fence guide takes 10 minutes, 20 at most. You need four strips of plywood or MDF, and a few drywall screws. Attach a stop to one or both fences to limit the length of the cut. Position the jig, cut with the straight bit and then cut with the dovetail bit. Bang! Your slot is done. If you want to use a template instead, it can be made from a piece of 1⁄4” hardboard. Simply rout a slot in from one edge. Make the slot the width of the template guide you’ll use. Extend it no longer than necessary to get the length of slot you want. The template approach has several

For a stopped slot, trim one edge of the tail. Simply turn the piece to register its edge against the fence. Use a backup block, and cut.

advantages. You can use any two routers because the template guide, not the router base, is the registration device, but you do need two identical template guides. When you set up any of these jigs, be sure you clamp a strip of scrap tight to the edge of the work. This will prevent splintering on the edge, which is almost guaranteed to occur. To aid you in sizing the tails that will fit into the slots you cut, use your setup to cut a slot in a scrap of the working stock. You avoid having to fit the test-cut tails to a slot in a case side itself, if you have this piece available.

Grooving an Edge Doing an edge groove with a portable router is precarious. If you must do the cut this way, try using a laminate trimmer; it’s smaller and easier to perch on an edge. Or equip your router with two edge guides – if that’s possible – to trap the workpiece. Failing that, try the operation with one edge guide that has a wide facing attached to the tips of the guide. In contrast, the setup and cuts are simple on the router table. There are two operations. First, you plow a groove with a straight bit. Then you finish the groove with a dovetail bit. The work is guided along the router table’s fence during both cuts. The setup is straightforward. The fence is positioned to center the cut on the edge. It’s the same for both the roughing-out cut and the final dovetail cut. The workpiece is set on edge, pressed tight against the fence and fed across the cutter, right to left. Naturally, you should make at least one test cut to ensure that you’re content with the result before cutting the real workpieces. Save the test cut for fitting the tail (or make a separate piece for the purpose). Cutting a Tail Tails are most commonly done on the router table. There are some alternatives, of course, but it is fast and easy on the router table, so let’s focus on that approach. S L I D I N G D OV E TA I L S

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Use the same router bit for the tails as you used for the slots. This guarantees the geometry of the mating pieces will match. Close down the bit openings in the tabletop and fence as much as possible. For the tabletop opening, use the appropriate reducer in your router mounting plate, or a 1⁄8” hardboard auxiliary tabletop. For the fence, either close the split fence facings in against the bit, or apply a one-piece auxiliary facing and cut a zero-clearance opening with the bit. Set the bit height to match the slot’s depth. If you cut the slots on the router table, move directly from that to the tail cut without changing the bit setting. If you cut the slots with a portable router, use your cut sample as an aid in setting the bit height. Bring the fence into position, housing all but the very edge of the bit in the fence. Depending upon the size and proportions of the workpiece, you may want to add a tall facing to the fence. This may be worthwhile if you’re working something like a tabletop or chest lid, although I’ve found a well-placed featherboard (and my regular fence) is all I need for even these big pieces. The drill is this: Make a test cut on a scrap of the working stock. The scrap

must be exactly the same thickness as the real work. I think it’s most effective to creep up on the fit. That is, start with a “fat” tail and check it against the grooved sample. Make a fence position adjustment, recut (on both sides of the tail), and recheck the fit. I keep trimming the initial sample until I get the right fit. My final assessment is based on a fresh sample. Assessing the fit: How tight you make the fit depends on the application. A short joint, such as one that joins a drawer divider to a case side, should close at least halfway with hand pressure and require only a tap or two to seat. You’ll be able to assemble it with glue, and the glue line will look nice and tight. If you have to pound the tail into the slot, it’s too tight for gluing. If it slides home with firm hand pressure, the fit isn’t ideal, but the joint will hold well when glued. Finally, if the tail piece sides into the slot easily, and especially if it wiggles from side to side, you need to start over. The tail is too small. With the right fit, the sliding dovetail will provide years of strength and beauty.

Edge grooves are best done on the router table. Set the fence to center the bit on the edge, and make the cut. Reduce stress on the dovetail bit by preplowing the groove with a straight bit. Minimize the tabletop opening – here with a hardboard overlay held in place by the fence – to prevent the work from catching on the opening as you start the cut.

One well-placed featherboard will stabilize even a large panel on end, so you can rout a tail across it. The featherboard is aligned just ahead of the bit, and it is elevated so it’s pressing above the cut. The fence is my regular one.

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CH A P T ER • 21

Variable Spaced Dovetails BY DON MEANS

Some of us just don’t have the time, patience or skill to produce hand-cut dovetail joints and instead resort to one of the numerous dovetail jigs available on the market. However, at several hundred dollars apiece, not everyone can justify the expense of a variablespace jig, such as the Leigh D4R. Even if you do happen to own this fine jig, for certain applications I find it easier and more efficient to use a simpler jig. For example, when building cabinets or furniture for my workshop I usually don’t want to spend the time setting up my Leigh D4 (yes, I do own one). However, I still want the dovetail joinery to have aesthetic appeal. I’ve experimented with a number of dovetail router bit sizes and cutting angles and, using a basic fixed-finger dovetail jig, have refined two techniques that greatly improve the overall aesthetics of the resulting half-blind dovetail joint. In addition, with a bit of planning, and within certain limitations, it is even possible to create “variable-spaced” half-blind dovetails with this “fixed-finger” jig.

Dovetail Jig Geometry In order to fully utilize these techniques, it is helpful to have an understanding of the geometry surrounding the dovetail joint produced by the fixed-finger jig. Although jigs of this type generally operate the same way (that is, the pins and tails are produced in a single operation) not all of them have the same geometric characteristics. For example, the Porter-Cable and Hartville jigs are similar, while jigs by Rockler, Jet and

Woodtek have slightly different characteristics. For this article, I worked with the Porter-Cable 4112 dovetail jig equipped with a 1⁄2” half-blind dovetailing template. However, it should be possible to apply this technique to just about any fixed-finger dovetail jig, once you understand the basic geometric relationships. When using a fixed-finger jig, the dovetail bit diameter and center-tocenter finger spacing are the critical dimensions that control the geometry of the dovetail joint. The key geometric relationship for the joint is the amount of overlap or interference between the tail and the pin. This relationship is determined by (1) the center-to-center finger spacing, and (2) the diameter of the dovetail cutter. The slope or angle of the dovetail bit is secondary to this relationship. In fact, this is what we are going to “play with” in order to improve the appearance of the joint. Adjusting the depth of cut determines the amount of interference between the tail and pin, and determines the fit of the joint. As the angle of the dovetail bit is reduced, it is necessary to increase the depth of cut in order to maintain the proper tail/pin interference. This reduced or slighter angle, as well as the increase in the depth, is the key to improving the appearance of the joint. For these types of fixed-finger jigs, the relationship between center-to-center finger spacing, cutter angle, diameter and, ultimately, cutter depth is defined VA R I A B L E S PAC E D D OV E TA I L S

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$FOUFSDFOUFS mOHFSTQBDJOH

"OHMF

Creating a Variable-spaced Dovetail Joint With a Fixed-finger Jig %FQUIPGDVU Skip these sockets

CRITICAL DOVETAIL DIMENSIONS

by the following formula: Depth of Cut = {D-S/2} á Tangent(a) where: D = dovetail bit diameter S = dovetail jig center-to-center finger spacing a =cutter angle (in radians) This formula provides the insight we are seeking. As you can see, for a given cutter diameter and finger spacing, the cutter angle is inversely proportional to the depth of cut. As the cutter angle is decreased the depth of cut must increase. This formula might be the end of our minor math lesson if we were cutting dovetails in metal with a precision CNC mill. Unfortunately, we are cutting with tools that have a variety of associated built-in errors (router and bit run-out, bushing and template fit and bushing/ router eccentricity, to name a few). All these factors result in an effective increase in the diameter of the cutter. A 1⠄2� cutter will tend to act like a slightly larger bit. With my equipment (the PC jig and a DeWalt 621 router) I found through trial and error that all of these imperfections added about .010� to the bit diameter. In other words, a 0.500�-diameter router bit acts like a 0.510�-diameter bit. This effective diameter should be used to calculate the estimated depth of cut provided in the preceding formula. (Note: Everyone’s tools are slightly different so you will have to experiment to find the amount of variation in your setup.) Planning the Width (Plus or Minus) For the majority of applications, the most aesthetic arrangement for halfblind dovetails is to end with a half-pin at the upper and lower edge of the draw-

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â–

1 ROUGH CUT THE TAILS. With the jig and depth of cut properly set, ďŹ rst take a back cut along the width of the drawer side. Then, as you normally would, start at the inboard end of the jig and rout out the ďŹ rst tail socket. However, do not rout the next slot in the jig template. Instead skip over the next two slots to the fourth slot. Rout out this tail socket, then again skip the next two slots and ďŹ nish up on the last slot (which should be the outside edge of the drawer side). As you look at the drawer front there should only be two tail sockets routed in the drawer front (or pin board) and two “wideâ€? tails that are roughly deďŹ ned on the drawer side.

4 FINISH THE TAIL SOCKETS. The next several steps in the procedure require you pay close attention to your work. Basically, we are going to manipulate the drawer front in the jig to hog out the unneeded pins in order to create two wide sockets for the wide tails we just milled. First, unclamp the drawer front and slide it toward the outboard side of the jig (to the right as you are facing the jig) exactly half the ďŹ nger spacing (do not unclamp the drawer side). At this stage the edges of the drawer front and sides should be aligned and it should become obvious which pins will be removed to create the wide sockets for the tails that were previously cut. Use the drawer side as a reference to square up the drawer front by pushing it up against the tails and re-clamp. At this point, there should be no tail sockets showing (in other words, all you should see are the individual pins). For this particular dovetail layout, unneeded pins will be removed using the second, third, ďŹ fth and sixth template “slotsâ€? (notice we skipped the fourth slot since this pin is aligned with the pin socket from the tail cutting operation). These steps in the procedure can get confusing if you are not careful. The safest strategy is to use a pen to mark the areas that are to be removed.

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Concave relief cut

Now cut here

2 FINISH THE TAILS. Next it is necessary to “finish” the tails by carefully removing the material on the back (or inside) of each of the tails. This is necessary to ensure the proper fit of the joint. Start at the left-hand side of the jig and carefully move the router from left to right between the template fingers, slightly “dipping” between the template fingers. (It is not necessary that this be a perfectly straight cut since it will be hidden in the assembled joint.) I usually make this cut slightly concave – just to ensure there will be no interference with the tail socket. Make sure you do not remove too much material as this will begin to affect the strength of the joint (obviously if you cut all the way through the tail you will have ruined the piece).

3 ROUGH CUT THE TAIL SOCKETS. Once the drawer side is complete we turn our attention to the drawer front (or pin board). First, unclamp the drawer side and lower it so the top of the tails are just below the tail sockets on the drawer front and then re-clamp (this is so the router bit will clear the top of the tails when cutting the tail sockets). Now rout out all of the tail sockets as you normally would.

Shift drawer front left

5 ROUT BETWEEN THE FINGERS. Once

the drawer front is marked and secure in the jig, rout out the marked areas between the template fingers. After this is complete you should be left with very thin sections of the former pins. Now unclamp the drawer front and slide it toward the inboard end of the jig (to the left) until these thin sections are centered in the template finger slots. As before, use the drawer side as a reference to square up the drawer front. Clamp the drawer front and hog out the marked sections. At this point it should begin to become obvious how we are manipulating the jig to produce the wide tail sockets. Once this is done, unclamp the drawer front, slide the piece in the opposite direction (to the right) until the remaining thin sections are centered in the template slots (again use the secured drawer side as a reference to square the drawer front in the jig) and repeat the cutting procedure.

6 READY TO ASSEMBLE. If

you performed these last several steps correctly when you remove the drawer front from the jig you will see two wide tail sockets that should perfectly match up to the wide tails previously cut. The joint is now complete and ready to be assembled.

VA R I A B L E S PAC E D D OV E TA I L S

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er side (or tail board). Unfortunately, when using a fixed-finger dovetail jig this requires the side of the drawer to be limited to certain widths. Some planning is necessary to ensure the joint ends on a half-pin. The Porter-Cable 4112 has a center-to-center finger spacing of 7⁄8” so in theory, drawer side widths have to be multiples of this dimension. But it isn’t necessary that the halfpins be exactly one-half the pin width. A typical 1⁄2”-dovetail cutter will produce a throat width that is approximately 3⁄ 8” (therefore the half-pin throat width would be about 3⁄16”). As long as you are close to this dimension (± 1⁄16” at most) the joint will look OK. Because there are two half-pins on each drawer side this allows a total variation of ± 1⁄8” over the drawer side. The chart below lists the

Drawer Side Width* MULTIPLIER OR FINGERS

NOMINAL WIDTH (INCHES)

MINIMUM WIDTH (INCHES)

MAXIMUM WIDTH (INCHES)

3

25⁄8

21⁄2

23⁄4

4

31⁄2

33⁄8

35⁄8

5

43⁄8

41⁄4

41⁄2

6

51⁄4

51⁄8

53⁄8

7

61⁄8

6

61⁄4

8

7

67⁄8

71⁄8

9

77⁄8

73⁄4

8

10

83⁄4

85⁄8

87⁄8

11

93⁄8

91⁄2

93⁄4

* Note: This chart provides the typical drawer side widths that are possible when using the PC 4112 dovetail jig and similar jigs with equivalent finger spacing. When properly set up in the dovetail jig, these widths will result in a half-pin at each end of the drawer.

possible sizes under this parameter. Most moderately priced dovetail jigs include a basic 1⁄2” diameter, 14º dovetailing bit. Under normal operation these cutters produce a “stubby” dovetail joint, with tails approximately 5⁄16” long. In addition, the 14º angle of the tail is not very graceful. Although there are a variety of dovetail cutters on the market, only a few have the proper cutting geometry that will allow them to work with the typical fixed-finger jig.See the chart below for cutters I have found that work with this technique.

A Simple Improvement A basic improvement when using the fixed-finger jig is to simply substitute a 1⁄ 2”-diameter, 8º cutter (such as the #80 bit for the Leigh jig) for the standard cutter. Set up the jig as you normally would by following the manufacturer’s instructions. The only change to the normal setup is the depth of cut – which should be set to about 25⁄32”. The actual length of the tail will be about 17⁄32”. However, when measuring the cutter depth from the base of the router, it is necessary to take into account the thickness of the finger plate (1⁄4” in this case). It will probably be necessary to finetune the depth of cut by experimenting with some scraps of wood. Simply follow the jig maker’s instructions for making these adjustments. Once you have fine-tuned the settings, you are ready to dovetail the final pieces. I like to back (or climb) cut the inside edge of the tails to create a clean inside edge for the pin sockets. Proceed

to cut the pins and tails as you normally would, then assemble the joint. The longer tailed, slighter-angled dovetail produced with this bit is an improvement over the standard cutter.

‘Variable’-spaced Joints It is also possible to create a variablespaced dovetail joint with the fixed-finger jig. Again, it takes a bit of planning to ensure that the drawer side ends on a half-pin. In addition, for certain drawer side widths it will only be possible to create asymmetrical dovetails. Another consideration is the number of tails that will show in the assembled joint. I find wider tails with an “odd” number of pins to be aesthetically pleasing. However, this imposes quite a limitation on the drawer widths that can be used. (If you limit yourself to this convention, it will only be possible to use the widths corresponding to the evennumbered multiplier in the “Drawer Side Width” chart on page 73 – assuming you wish to end up with symmetrical tails.) The following procedure outlines how to produce a variable-spaced dovetail joint that has two half-pins at the top and bottom of a 51⁄4”-wide drawer side and with a single full-pin in the center. As before, I used the 1⁄2”-diameter, 8º cutter for this example. Again, set up the jig as you normally would by following the manufacturer’s instructions – adjusting the depth of cut to about 25⁄32”. (As before, it may be necessary to fine-tune the depth of cut.) The sequence of accompanying photographs illustrates the procedure.

Commercially Available Dovetail Bits That Can Be Used in Fixed-Finger Jigs STANDARD

Cutter diameter

1⁄2"

Effective diameter 0.510" Angle or slope Depth of cut

LEIGH (#101)

INCRA

LEIGH (#80)

CUSTOM*

1⁄2"

17⁄32"

1⁄2"

17⁄32"

0.510"

0.542"

0.510"

0.542"

14°

10°

14°

1:6

19⁄64"

26⁄64"

27⁄64"

33⁄64"

5⁄8"

Most manufacturers make bits in the sizes listed above. * Whiteside will custom-make this bit (or any other for that matter) for a price of around $200. It is only shown here to indicate what the characteristics of the “optimal” router bit for this technique would consist of – if you are prepared to pay for it!

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CHAPTER • 22

Microadjustable Finger Joint Jig BY NICK ENGLER

Photos by Al Parrish

You find them lurking in bins in hardware stores, hanging out in plastic bags in home centers, rusting in baby food jars in garages and basements all across America: flathead machine screws with 32 threads per inch. Few of us ever suspect that these unpretentious bits of hardware could be so incredibly helpful, particularly to those of us who still use the ancient and venerable English system of measurements. These tiny bolts are a cure for many troubles that afflict our accuracy. They can eliminate the error from a trial-and-error method and turn a homemade jig into precision equipment. Consider the traditional finger joint jig. It’s designed to make evenly spaced square notches in the ends of adjoining boards, leaving multiple tenons that interlock to form a finger joint. The standard finger joint jig has just three parts: a back that you attach to your miter gauge, a movable face that feeds the wood into a dado blade to cut the notches, and a tenon that aligns the wood for each cut. To set up this jig, you must move the face right or left, adjusting the space between the tenon and the dado blade, so the fingers will be properly spaced. If the fingers are too close together, the joint will be loose. If too far apart and they will be too tight to assemble easily. Positioning the face properly is often a frustrating loop of trials and errors. Cut a finger joint, test the fit, move the face, cut another joint, and so on. But if you add one more part to this jig — a small wooden block that mounts a M I C R OA D J U STA B L E F I N G E R J O I N T J I G

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#10-32 machine screw and serves as an adjustable stop — you can escape this frustration. Because the machine screw has 32 threads per inch, one turn will move it precisely 1⁄ 32”, one half turn moves it 1⁄ 64”; one quarter turn, 1⁄ 128”. When the flat head is resting against the face, the face will move a precise amount. No guesswork! When constructing this finger joint jig remember that the tenon must be precisely the same width as the fingers you wish to cut. I made several faces for my jig, each with different sized tenons.

Make the tenon and stop from hardwood such as oak or maple. Drill a 5⁄ 32”-diameter hole for the machine screw, then cut threads in the hole with a tap. (You can purchase a #10-32 tap at most hardware stores.) Oak and maple are hard enough to hold the fine threads, but soft enough that they spring back and hold the machine screw in position. To make it easier to turn the machine screw, install a knurled nut on the end and tighten a stop nut against it. These stops have many other applications besides finger joints. I use them as fence stops on my router table and drill

press. I’ve incorporated them in cut-off boxes, tenoning fixtures, and other applications where a small adjustment can make the difference between good craftsmanship and great craftsmanship. Tip: To keep the dado blade from splintering the wood where it exits the cuts, scribe the length of the fingers on the board. Make the fingers about 1⁄ 32” longer than the width of the board so they protrude slightly when you assemble them. Later you can sand the ends and faces flush.

Making a Finger Joint

1

2

Initially, set up the finger joint jig by making a few rough measurements with a ruler. The tenon, the dado blade, and the distance between them should all be the same width, in this case, 1⁄ 4".

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Make a test cut. Butt the edge of the board against the tenon and feed the wood forward, cutting a notch. The resulting tenon should be exactly 1⁄ 4" wide.

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3 To cut multiple fingers, move the board sideways, fit the notch over the tenon, and cut again. Continue until you have cut all the fingers. Note that the last finger on this trial board is not as thick as the others.

5 When the jig is properly adjusted, it’s time to cut the good stuff. Make a single finger in one of the adjoining boards as you did in Step 2. Turn the board edge for edge and fit the notch over the tenon. Use the first board as a spacer to make the initial cut in the second board.

4 Since the board is 4" wide and the fingers are supposed to be 1⁄ 4" wide, the fingers should have come out evenly. Checking with a micrometer, I find they are 1⁄ 64" too narrow— the tenon needs to be 1⁄ 64" further away from the dado blade. I loosen the face and turn the machine screw 1⁄ 2 turn.

6 Place the notches in the boards over the tenon and cut more notches. Continue, cutting both adjoining boards at once. Note: If the fingers are spaced properly and the joint is still too tight or too loose, adjust the width of the dado blade. I invested in a set of thin brass dado shims just for this purpose.

M I C R OA D J U STA B L E F I N G E R J O I N T J I G

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CHAPTER • 23

Super Simple Dado and Rabbet Jig BY NICK ENGLER

When building a bookcase, you often must make a series of repetitive dadoes in the long uprights to support the shelves. You could do this on a table saw with a dado blade, but you’ll find it’s difficult to control the long stock as you feed it over the blade. If you have a router, you could clamp a straightedge to the stock and use it to guide the router, but it’s time-consuming to measure and set up for each individual cut. The dado-and-rabbet jig simplifies both the set-up and the operation. Lock the board between the base and clamping bar, then guide the router along the bar. The stock doesn’t move, so you don’t have to worry about controlling a large piece of wood. The straightedge is also the clamp, so the set-up is very simple. And that’s not all it does. The jig helps create any long dado, rabbet or slot. You can make repetitive cuts in multiple parts. And you can use it to guide other hand-held tools to make straight cuts, such as a sabre saw or a circular saw.

Making the Dado-and-Rabbet Jig The jig is just two pieces of wood (a base and a clamping bar). The sizes of both parts is determined by your own needs. My jig is about as long as my workbench is wide. This allows me to clamp the ends of the base to the bench. Not only does this keep the jig from moving around while I’m using it, it also keeps the base flat when I tighten the clamping bar against the stock to be routed. Make the base from 3⁄ 4” plywood and the clamping bar from a hard, dense 1 16

Cutting dadoes in long pieces of material is fast and easy with this simple jig.

wood such as oak or maple. The bar should be fairly thick from top to bottom so it doesn’t bow when tightened down. If it bows, the clamping pressure won’t be even all across the stock. In fact, the

bar will only press against the stock at the edges and the stock will be more likely to slip. This becomes more and more of a problem the longer you make the clamping bar. To solve it, I crowned the

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To make a positioning gauge, clamp a scrap under the clamping bar so you won’t cut into the base. Rest a scrap of 1⁄ 4" plywood or hardboard against the bar and secure it to the scrap with a separate clamp. Then rout through the material, saving the strip between the router bit and the clamping bar.

the bar over so the springs are no longer recessed in the counterbores. (This, by the way, is why I crowned both the top and bottom of the bar.)

Making Dadoes and Rabbets To use the jig, first you must position the stock on the base under the clamping bar. To do this quickly and accurately, it helps to make a positioning gauge from a scrap of thin plywood or hardboard. Lock the bar down on the base and

place the scrap so one straight edge rests against the side of the bar. (The scrap mustn’t be under the clamping bar.) Mount the bit you will use to make the cuts in your router, then rout all the way through the scrap, creating a strip about as long as the bar. This width of this strip is precisely the distance from the edge of the router to the cutting edge of the bit, and it becomes the positioning gauge for that specific router and that bit.

Clamp bar

Attach self-stick 100# sandpaper to bottom edge 3/8"

x 5" carriage bolt, flat washer, 0.030" x 13/32" I.D. x 3/4" long compression spring and wing nut (2 sets required)

Base

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Illustration by Mary Jane Favorite

top and bottom surfaces of the clamping bar, making it 1⁄ 32” to 1⁄ 16” thicker in the center than at the ends. Even though the bar flexes, the clamping pressure remains even. However, remember that the sides of the clamping bar (the surfaces that will guide your router) must be perfectly straight. Tip: To keep the stock from shifting in the jig, apply self-adhesive sandpaper to the underside of the clamping bar. In some cases, you may also want to apply a strip of sandpaper to the base, directly under the bar. Drill counterbored holes for the carriage bolts in both the base and the clamping bar. The counterbores in the base recess the heads of the bolts so the base will rest flat on the workbench. The counterbores in the clamping bar provide recesses for the compressed spring, allowing you to clamp thin stock. The purpose of these springs, of course, is to automatically raise the bar every time you need to move or remove the stock. What do you do if you’re routing thick stock and the springs don’t reach far enough into the counterbores to raise the clamping bar? Simply turn

Use the positioning gauge to align the stock underneath the clamping bar. The edge of the gauge indicates the inside edge of the cut.

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You can rout multiple parts by stacking them edge to edge or face to face. However, you must be very careful that all the parts are secure under the clamping bar. If there is a slight discrepancy in the thickness of the pieces, one or more parts may shift during the cut. To prevent this, you may have to use additional clamps to secure individual pieces to the base.

Lay out the cut you want to make, slide the stock beneath the bar, and turn the wing nuts so the bar is snug against the stock, but not tight. Place the positioning gauge against the clamping bar and line up your layout marks with the edge of the gauge. Then tighten the bar down and remove the gauge. Rout the dado or the rabbet, keeping the router against the side of the clamping bar. This is like any other router operation (feed the router left to right as you face the bar so the rotation of the bit helps hold the router against the guiding edge). Make deep cuts in several passes, routing about 1⁄ 8” deeper with each pass. If your router has a flat side to its base, keep that pressed against the fence. If the base is round, you may want to mount the router to a square sole for this operation. Router bits aren’t always perfectly concentric to the sole, and the bit may move in and out slightly from the clamping bar if the router turns as you make the cut. This will make the cut curved or wavy. The jig is not only useful for cutting dadoes and rabbets in wide stock, it’s a 1 18

To make multiple identical cuts, such as cutting the cheeks and shoulder of tenons in several rails, clamp a short fence to the base to automatically position the parts. Always check with the positioning gauge, however, before you make each cut.

timesaver for making identical cuts in multiple parts. You can line up the parts under that clamping bar and cut several at once. For example, you can makes tenons in the ends of multiple door rails by cutting four identical rabbets in the end of each piece. To do this, first position two parts under the clamping bar, one near each end. Then clamp a short fence, no taller than the stock is thick, against the ends of the parts. This will automatically position the rails for each cut you make. Line up several rails edge to edge with the ends against the fence and lock the bar down on top of them. Check to see that each part is secure. If it shifts, you may have to add another clamp behind the clamping bar. Rout the faces of the rails, then turn them over and repeat. After routing the faces, make identical cuts in the edges. If the router seems unstable when routing the edges, either wait until you have enough parts to stack face to face to make a larger platform for the router or put spacers between the parts to spread them out.

PROJECT 23

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CHAPTER • 24

The Joint Maker BY NICK ENGLER

This horizontal routing jig, which I call “Joint Maker,” holds the router to one side of the work. This setup offers several advantages over a standard router table for certain operations: • You have more control when making mortises – you can rest the part on its face and feed the edge into the bit. • When making tenons, the rotation of the bit doesn’t pull the work sideways

as it does on an ordinary router table. Instead, you cut directly against the rotation. • And if you use vertical panel-raising bits, you’ll find that with the panel resting flat on the worktable, gravity works for you. I’ve built several Joint Makers throughout the years and I’ve noticed that the most serious limitation encoun-

tered is in routing small, narrow parts – your hands come too close to the bit for safe, accurate control. So I added a carriage on this one – essentially it’s a sliding table. It works wonderfully. Just clamp the workpiece to the carriage and use it to feed the work into the router bit. Four stops on the carriage help position the work and control the cut. A unique cross slide keeps the work perTHE JOINT MAKER

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fectly aligned with the bit, yet allows you to feed it front-to-back and side-to-side.

How Do I Build It? In essence, the Joint Maker is just a Baltic birch plywood box with two flat work surfaces – one vertical, one horizontal – mounted to it. The vertical surface (or router mount) is attached to the back of the box and holds the router. The horizontal surface (or carriage) slides over the top of the box and holds the work. Cut the parts to the sizes given in the cutting list. Rout 3⁄ 4”-wide x 1⁄ 4”-deep grooves in the top surface of the top and the bottom surface of the carriage, as shown in the illustrations on page 81. Note that the grooves in the top run front-to-back, while those in the carriage run side-to-side. The grooves fit around the cross slides. Cut the shape of the top and crossslide mount. The top has a “fixed stop” on one side and a cutout in the other. Then cut a 21⁄ 4”-diameter dustcollection hole in one of the end pieces. Next, you should drill a 5⁄ 16”-diameter pivot hole for the router mount in the back side. Assemble the bottom, sides, ends and baffle (which is a dust-collector diverter) with glue and screws. Insert the carriage bolt that serves as the pivot for the router mount through the pivot hole in the back side, then screw the top in place. But don’t glue the top to the assembly – I found that out the hard way. If the pivot bolt happens to fall out, you can lose

Illustrations by Mary Jane Favorite

5⁄16" x 2"-long carriage bolt, flat washer and wing nut (2 sets required) 3⁄8"

Fixed stop

The sliding carriage has several straight slots with a 3⁄ 4"-diameter hole at one end for you to mount the stops without having to remove the hardware. Just insert the head of the mounting bolt in the hole and slide the stop in.

your religion trying to get it back in. (Of course, had I been smart, I would have epoxied the bolt in place.)

Mounting the Router Attach the router to a clear plastic plate before putting it in the router mount. Because this router mounting plate is thinner than the board it attaches to, this arrangement gives you a fraction of an inch more depth of cut. More importantly, it lets you see what the router is doing as you cut. To attach the plastic plate to the router mount, make a cutout and rabbet the edge to accept the mounting plate. 5⁄16"x 2" carriage bolt, flat washer and stop nut

5⁄16"-wide slot 1⁄4" with 3⁄4" x chamfer 1⁄4"deep c'bore (2 places)

16"

Attach the router mounting plate to the router mount with #10 flathead sheetmetal screws. When installed, the router mounting plate must be flush with the work surface of the router mount. The heads of the screws must be countersunk in the mounting plate so they rest slightly below the surface.

Cutting the Slots There are two types of slots in this fixture. The carriage has several keyhole slots – straight slots with a 3⁄ 4”-diameter hole at one end. The holes let you mount the stops and clamps instantly, without having to remove the hardware. Just

3⁄8"-wide x 3⁄8"-deep

5⁄16"x 3" hanger bolt, flat washer, fender rabbet washer and wing nut #150-grit 18" PSA 8" 5" sandpaper 3 2" ⁄8" (typ) (adhered to box 3 2" 11⁄2"dia. 8 ⁄4" 2" surface) 8"

13 3⁄4" 3⁄4"

4"

8 7⁄8"

21⁄4" diameter

3" 6" 11⁄2"

101⁄2" PROFILE

1 20

Stops limit the travel of the sliding table

51⁄2"

5 1⁄2" radius

14" radius

7 1⁄8"

8 3⁄4"

11⁄2"

2 5⁄8"

5⁄16"

11⁄8" 16 1⁄2" (baffle) BACK VIEW

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N P L

P

L

C

B M

M

G

J K

L H

B

F E A F

E

D

EXPLODED VIEW

The Joint Maker NO.

ITEM

Hardware DIMENSIONS (INCHES) T W L

1

A

Baffle

3⁄

2

B

Top/carriage

1

C

1

MATERIAL

❏ 5⁄ 16" x 2" carriage bolts (6) ❏ 5⁄ 16" x 5" carriage bolts (3)

4

6

161⁄ 2

Baltic birch plywood

3⁄

4

16

18

Baltic birch plywood

Router mount

3⁄

4

133⁄ 4

18

Baltic birch plywood

D

Bottom

3⁄

4

12

24

Baltic birch plywood

2

E

Ends

3⁄

4

6

101⁄ 2

Baltic birch plywood

2

F

Sides

3⁄

4

6

18

Baltic birch plywood

1

G

Router mounting plate

3⁄

8

83⁄ 4

83⁄ 4

Acrylic plastic

❏ #10 x 3⁄ 4" flathead sheet metal screws (8) & nuts

2

H

Front-to-back slides

1⁄

4

3⁄

4

113⁄ 4

Baltic birch plywood

❏ #12 x 11⁄ 2" flathead wood screw

4

3⁄

4

❏ 5⁄ 16" flat washers (15) ❏ 5⁄ 16" wing nuts (8) ❏ 5⁄ 16" fender washer ❏ 5⁄ 16" stop nut ❏ 5⁄ 16" x 3" hanger bolt

2

J

Side-to-side slides

1⁄

18

Baltic birch plywood

1

K

Cross-slide mount

1⁄

4

113⁄ 4

18

Baltic birch plywood

❏ compression springs (3) 0.030 wire x 11⁄32" I.D. x 5" long

4

L

Stops

3⁄

4

11⁄ 2

11⁄ 2

Hardwood

❏ #8 x 13⁄ 4" flathead wood screws (45)

❏ ❏ ❏

4 3 3

M N P

5⁄

Stop pins

1

Clamps

3⁄

Clamp jaws

3⁄

4

2

4

3⁄

4

5

3⁄

2

4

16” diameter

Baltic birch plywood

❏ 5⁄ 16" x 4" full-thread hex bolts (3) ❏ 5⁄ 16" T-nuts (3)

Baltic birch plywood

THE JOINT MAKER

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You can make a counterbored slot in two steps. First rout the wide “counterbore groove” that forms the step inside the slots .

Then rout a slot down the middle of the groove, cutting completely through the stock in four 1⁄ 8"-deep passes.

insert the heads of the mounting bolts in the holes and slide the stop sideways in the slot. The slots let you position the stops and clamps wherever you need them when making cuts. Note that these slots are counterbored, which helps hold the heads of the bolts so they don’t rub on the top of the fixture. To make the keyhole slots, drill the 3⁄ 3 4”-diameter holes first. Then rout ⁄ 4”1⁄ wide x 4”-deep counterbore grooves using a straightedge as a guide. Without changing the position on the router guide, change bits and rout a 5⁄ 16”-wide slot through the middle of each groove. The other slot used in this Joint Maker is the curved slot in the router mount. To rout this slot, attach the router to a router compass jig. Insert a pivot bolt through the compass and the mount, then swing the router in an arc as you cut.

Make the Cross-slide Mount The cross-slide mount is a simple assembly, but you have to get all four of the slides positioned correctly for it to work well. The best way I found to do this was to use the tool itself as a glue-up jig. Place a single layer of thin plastic in the grooves in both the top and the carriage (a plastic grocery bag works well). Then press the slides into their grooves on top of the plastic. Apply a thin bead

of glue to the exposed surface of each slide. Place the cross-slide mount on top of the slides in the top, then place the carriage (with the slides in place) on top of it. Don’t worry if there’s glue squeezeout; the plastic will prevent it from accidentally bonding surfaces that shouldn’t. Make sure everything lines up properly and the back edge of the carriage is flush with the back of the Joint Maker. Then clamp the parts together and let the glue dry. After it sets, take the carriage, cross slide and Joint Maker apart, and trash the plastic.

Make the Stops and Clamps The stops and clamps are all attached to the carriage by carriage bolts. The stops are just blocks of wood with dowels protruding from the underside to keep them from rotating while in use. Chamfers around the bottom edges prevent sawdust from interfering with the accuracy of your setup. I found that as sawdust builds up around the stops, it prevents the parts from making full contact. This, in turn, keeps you from positioning the parts correctly. The chamfers give the sawdust somewhere to go. You will still have to brush the dust away from time to time, but you don’t have to get every little particle. On the clamps, a compression spring around the mounting bolt automatically

Router compass jig To rout the curved slot in the router mount, first make a router compass jig to guide your router in an arc. Drill the 5⁄ 16"-diameter mounting hole in the router mount and mark the ends of the curved slot. Use the mounting hole as the pivot and swing the router in an arc to cut the slot.

1 22

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raises the clamp when you loosen the knob. A hex bolt threaded into a T-nut at the back of the clamp prevents the assembly from tipping when you apply pressure. Make as many clamps and stops as you think you’ll need. I made just three clamps and four stops, which I’ve found to be adequate for the work I do. But if you think you’ll need more, now is the time to make them. As another option (if you’ve got a few extra dollars) there are a couple of hold-down clamps available from catalogs that will also work very well when attached to the Joint Maker (see “Some Store-bought Options to Improve the Joint Maker” on page 128 for more.

Final Assembly, Finishing Give all the wooden surfaces a light sanding, then apply a durable finish to all parts of the Joint Maker: the router mount, carriage, cross slide, clamps and stops. Apply a thin coat to all exposed surfaces, then rub down those surfaces that will slide together (such as the back and the router mount, or the top and the cross slide) with steel wool or fine abrasive pads. Then apply a coat of paste furniture wax to the sliding surfaces of the top, cross slide and carriage, and buff it out. The thin layer of wax lubricates the surfaces and helps the parts slide much more easily. Attach the router mount to the Joint

Countersunk pilot hole for #12 x 11⁄2"-long flathead wood screw

Maker with a pivot bolt, washer and a stop nut. Using the curved slot as a guide, drill a 1⁄ 4”-diameter pilot hole for the hanger bolt in the edge of the top. Install the hanger bolt, fender washer, flat washer and wing nut, as shown in the illustrations. Also install the hardware in the stops and clamps. The carriage and cross slide are not attached; they simply rest atop and slide on the Joint Maker. Once you’ve done that, you’re ready to test it out on all your joint-making operations. PW

6" 2 3⁄4"

5 1⁄8" 3⁄4"

113⁄4"

radius 1⁄4"

3⁄4"

12"

5"

18" CROSS-SLIDE LAYOUT - PLAN 3 ⁄8" (typ)

18" 24"

3"

3⁄4"

4" 3⁄4"

3⁄4"

CARRIAGE LAYOUT - PLAN

4"

CROSSSLIDE LAYOUT - PROFILE

CROSS-SLIDE LAYOUT - ELEVATION

2" 2"

6" 4"

23⁄4" 3"

8" 3⁄4"

4"

3⁄4"

4"

3⁄4" 3⁄4"dia

thru

5⁄16"

3⁄8"-deep

slots

5"

16" 3" 3"

3⁄4" 3⁄4"

6"

12"

51⁄4"

11⁄4" 8 1⁄4"

13⁄4"

8 1/4" 18"

CARRIAGE LAYOUT - BOTTOM VIEW

1 3/4" 18"

TOP LAYOUT - PLAN

THE JOINT MAKER

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11⁄32" dia. thru with 15⁄16"-dia. x 1⁄16"-dp. counterbore for 5⁄16" T-nut

5⁄16"

2" 5⁄16"

1" 3⁄4"

3⁄4"

1⁄2"

1⁄2"

dia. 1⁄2"

2 3⁄4"

5⁄16"x 1⁄2"-deep

11⁄2"

5 3⁄4"

CLAMP DETAIL - PLAN

11⁄2"

5⁄16"

x 4" full thread hex bolt and T-nut

hole with 1"-long dowel

STOP DETAIL - PLAN

#150-grit sandpaper 1⁄8"

chamfer

3⁄4" 3⁄4" 3⁄4"

1⁄2"

3⁄4"

STOP DETAIL - ELEVATION

5⁄16"-dia.

x 5" carriage bolt, 3 flat washers, compression spring with 11⁄32" I.D. x 11⁄2" x .030" wire and wing nut CLAMP DETAIL - PROFILE

Some Store-bought options to Improve the joint maker When we had a chance to work with the Joint Maker in the Popular Woodworking shop, we were definitely impressed with the cleverness of the design. Our minds were spinning with the amazing number of operations that could be performed easily with this homemade jig. We also let our minds wander a little further about some of the features of the jig. After adjusting the numerous wing nuts (especially when applying hold-down torque to such a small surface area), we decided that some very affordable handles would make the jig more user-friendly. T-handle, star and three-wing knobs are available for 50 cents to $2 each, and make gripping and tightening the adjusters a whole heck of a lot easier. Another addition we felt would be useful were some optional manufactured hold-downs. While Nick’s hold-downs function well, there are a number of other hold-downs available for less than $5 that offer slightly better performance. The store-bought hold-downs shown

1 24

at right will work with the slots as shown in the plans, and by purchasing them you’ll reduce the time necessary to build the jig and get you using it more quickly. The jig knobs are available from a number of sources, including your local Lowes. The hold downs shown here are available from Hartville Tool (800-345-2396 or hartvilletool.com, item #60736) costs $10.95 and includes a solid aluminum hold-down, a bolt and a 1⁄ 4"-20 knob. – David Thiel

While the four-prong “star” knobs are easiest to grab, the two-prong “T” knobs require less clearance. The hold-down at left also works in the Joint Maker’s slots.

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Using the Joint Maker to Create a Haunched Mortise-and-Tenon Joint

1

2

You can cut grooves on the inside of edges of rails and stiles with a straight bit. Lock the carriage to the base with a wood screw and feed the parts past the bit, guiding them along the mount.

3

To cut the mortise, clamp a stile to the carriage so the inside edge faces the router. Adjust the hex bolts so the clamp jaws sit squarely on the work while you tighten the knobs.

Secure a stop against the end of the stile to quickly align the other stiles. This makes it a lot easier to make the same cut in multiple pieces without having to set it up each time.

5 4 Advance the router bit to cut the full depth of the mortise. Holding the carriage, feed the stock into the bit no more than 1â „ 8" deep at a time, moving it side to side.

For the tenon, mount a rail on the carriage so the edge is perpendicular to the mounting plate. Secure stops against the rail to help you position the others for duplicate cuts.

6 You can use the wooden clamp as a stop to prevent the bit from cutting into the carriage as you work.

Feed this direction

7 Once you set up the stops and clamps to cut the tenons just as you want them, feed the rail across the bit, cutting the underside of the stock. With the cutter below the work, you need to pull the work toward you to cut against the rotation of the bit.

8 To cut the tenon’s shoulders, turn the rail so the outside edge rests on the carriage and clamp it in place. Readjust the router bit and cut the haunch in the tenon, using the carriage to feed the work and control the cut.

THE JOINT MAKER

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â–

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CHAPTER • 25

Table Saw Tenon Jig B Y B I L L H Y LT O N

The mortise and tenon is one of those fundamental joints you’re obligated to master. It’s used for building frames of all sorts (including post-and-beam architectural frames), as well as tables and chairs. Over the years a variety of substitute joints and alternative constructions have been contrived to circumvent the mortise and tenon. I don’t know why. The joint can be cut many ways, using different tools. For every woodworker, regardless of tooling, experience and self-perceived skill level, there must be a method that can be mastered. If you’re still looking, here’s yet another approach for cutting tenons. If you want to saw your tenons, the band saw and the table saw are the obvious choices.Cutting tenons on the band saw has its devotees, but I’m not one of them. Of the two saws, I prefer the table saw for this job, primarily because the finish cut is better for the purpose. Cheeks and edges cut with a table saw blade are smooth and flat, while bandsawed surfaces tend to be finely ridged, and occasionally hollowed or bellied. On the table saw, you can cut tenons with a dado head, or with a regular blade and jig. I favor the latter approach. While you can buy a high-quality tenoning jig, I use shop-built ones that depend on the rip fence for positioning. (Plans for jigs that ride in the miter slot are common, too.) The one I’m currently using is shown above. Obviously, the rip fence must be parallel to the blade, or the tenons won’t be accurate. (If you’re a woodworker who 1 26

favors having the rip fence ever-so-slightly angled away from the blade, this arrangement won’t work for you. Instead, use a tenoning jig that’s guided by the miter-gauge slot.) In brief, my tenoning sequence is this: Elevate the blade to match the tenon length, set the tenoning jig on the rip fence, adjust the fence to position the cut, clamp the workpiece in the jig, and cut the cheeks (and, A good tenoning jig, whether purchased or shop-made, must be accurate and easy to adjust. It should allow you to sometimes, the edges). position, reposition, and swap workpieces without a lot of This leaves the cheek waste fumbling, especially with separate clamps. I use mine with a attached to the workpiece. combination saw blade; a rip blade will work well, too. To form the shoulders and separate this waste, lower the blade to I can turn the workpiece 90° between match the shoulder width, then use the passes, and cut the cheeks and edges in miter gauge to guide the cuts. sequence (assuming the shoulders are Now, this may seem out of order. It’s a uniform width). To make the coarse certainly not the way I sawed tenons at fence setting, measure from the jig to the the start. When I cut the shoulder first, outside of the blade with a metal rule. those wafers sliced away by the cheek The fine fence setting is made after cut were trapped between the jig and the cutting the cheeks on a test piece and blade, and would crunch disconcertingseeing how it fits in the mortise. Just ly. They would then either fire around remember to trim both cheeks each the table or virtually explode. Now, the time you adjust the fence, so the tenon wafers of waste accumulate, harmlessly, remains centered on the workpiece. to the right of the blade. I micro-adjust my fence with a shopmade block I park on the fence rail. • To move the fence closer to the Set the Saw and the Jig blade (thus increasing the tenon thickSetup is easy: Determine how long the ness), I butt the block against the fence tenon is to be and crank up the blade to and clamp it. I shift the fence, insert a that height. Position the tenoning jig next. I make shim at the end of the block and move the fence back against the block. The the cheek cut on the side of the worknew position is offset from the old by piece that’s against the jig. That way,

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Stop

With the jig straddling the fence, slide the jig to the blade, and measure to the outside of the blade.

With the workpiece seated squarely against the table and the vertical work support, pull the cam clamp to secure it, and make the cheek cut.

the shim’s thickness. • To move the fence away from the blade (thus reducing the tenon thickness), hold the shim against the fence, push the reference block against it and clamp the block. Remove the shim and seat the fence tight against the block. The thickness of your shims controls the movement. You can use feeler gauges, shim stock or paper to make the adjustment. Measure the test tenon with a dial caliper, and compare that measurement with the mortise-width dimension. You can nip off the waste on the band saw to expose the tenon for a test fitting, too. The shoulder need not be perfect for you to determine whether or not the tenon fits the mortise. With the blade and jig set (proven through a test tenon that fits the mortises properly) cut the cheeks. Stand the workpiece on end, clamp it in the jig, and feed it through the cut. Use both hands to advance the jig. After cutting the first cheek, release the clamp, rotate the workpiece, reclose the clamp and cut again. With the cheek-cutting done, set the tenoning jig aside, slide the fence back and lower the blade. Get out the miter gauge; all that’s left is cutting the shoulders. Clean and accurate shoulder cuts are important for final appearance and strength. Use a real tenon, one from which you’ve pruned back the waste to expose the cheek, as a gauge to set the blade height. At top dead center, the teeth should just graze the cheek. Because you’ll be severing waste from

Making the shoulder cuts after the cheek cuts simplifies accurate setting of blade height, and eliminates flying offcuts. A stop on the miter gauge ensures consistent cuts all around the tenon shoulder.

the piece, you shouldn’t use the rip fence to govern the tenon length unless you use a stand-off block. I use a stop on my miter gauge to control the tenon length. You can set the stop at the far end of the piece, or you can use a miter-gauge fence that extends well beyond the blade to the right and locate the stop there.

Slip Joint Years ago, before I mastered mortising, I used the slip joint instead of the mortise and tenon for frames such as simple doors. I could cut both halves of this joint on my table saw using the same jig. The joint is strong, but it doesn’t look as clean as the mortise and tenon. The slip joint, in case the name is new to you, is often called the open mortise and tenon. There’s good reason for this. The rails have a tenon, and the stiles have a mortise that’s open at the top, bottom and on one edge. Essentially, this open mortise is a notch. A subset of the slip joint is one that joins the end of one piece to the middle of another. This is called a bridle joint. A major advantage of the slip joint is the ease with which it’s made. Its disadvantage emerges during assembly: In addition to clamping the tenon shoulder tightly against the mortise (as you do in all mortise-and-tenon glue-ups), you must clamp the mortise cheeks to ensure they bond to the tenon cheeks. We were all beginners at some point. If you have a table saw, you can make this joint. If you have a table saw but no mortiser, no plunge router, and no desire to test your hand-tool skills, even with

To cut the slip joint’s halves, use a tenoned piece to reposition the rip fence. Cut the notch’s inner cheeks and reset the fence to remove the waste. The added screw shaft on the jig fence keeps the cam-clamp handle away from the blade.

A slip joint features a tenon shouldered only on the faces (no edges) and notch, or an “open” mortise, instead of a regular mortise.

an assist from a drill press, don’t fret. Use the slip joint for your frame constructions.

TA B L E S AW T E N O N J I G

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Table Saw Tenon Jig Saw accurate tenons with this shop-built jig. You simply drop it over the rip fence and use it with your table-saw’s work-a-day blade. You can build one, including the cam clamp, from a small amount of 3 ⠄4" plywood, a couple scraps of hardwood, and some commonplace fasteners in two or three hours. The jig isn’t original. You’ve undoubtedly seen photos of it in magazines and books, and perhaps you’ve made one yourself. My iteration has a replaceable work support that’s backed up by a blade-guard block. This work support may get chewed up. By backing out a pair of connector bolts, you can replace it. (Note that the lower bolt must be

workpiece wants to creep as pressure is applied, it will be pushed against the saw’s table, rather than being pulled off the saw’s table. The exploded drawing and the cutting list should make the construction clear. The drawing shows biscuit joints, but you can use screws or nails. — BH

located high and clear of the blade.) The blade block will house the segment of the blade that passes through the work support. To secure the workpiece, I opted for a shop-made cam clamp. The clamp is easy to make, and its location can be adjusted to accommodate different widths of stock. I oriented the clamp pivot so it tightens onto the work as you pull the handle toward you. If the

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REAR ELEVATION

  

 PROFILE



Tenon Jig NO.

ITEM

DIM ENSIONS ( INCHES) T W L

â?? 1 Fence ž 11 17 â?? 1 Trap fence ž 5½ 17 â?? 2 Fence ties ž 4* 17 â?? 3 Buttresses ž 4ž 4ž â?? 1 Work support 1 2 11 â?? 1 Blade block 1 5ž 4 â?? 1 Cam clamp ž 4 9 *width of rip fence 2 - Âź" x 20 connector bolts, 2" 2 - Âź" T-nuts 1 - Roundhead stove bolt, nut and washers, Âź" x 1½" 1 - Roundhead stove bolt, nut and washers, Âź" x 2" 2 - Fender washers, Âź" i.d.

1 28

â–

FRONT ELEVATION

M ATER IA L

Baltic birch Baltic birch Baltic birch Baltic birch Hardwood Hardwood Baltic birch







 

  





%SJMMFEBOE DPVOUFSCPSFE GPSUOVU

  

 FENCE LAYOUT

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CHAPTER • 26

Dovetail Jig BY JIM STUARD

Years ago when I first learned to cut dovetails, my first joints weren’t things of beauty. Sometimes there were more shims than pins. Over time, my work got better and faster. But despite the improvement in my skills, I still had trouble cutting tails or pins consistently, especially if I got out of practice. This jig allows you to make great dovetails on your first day. The idea came to me when I was building a Shaker stepstool using hand-cut dovetails. I made a jig that fit over the end of a board to guide my saw through the cut and provide a perfect tail. The jig didn’t cut pins and only worked on 3⁄ 4”-thick

boards. I guess I wasn’t thinking big that day. A few weeks later it came to me: Why not build a jig that cuts both tails and pins and is adjustable to a variety of thicknesses? So I made this jig. From the first joint I cut using it, I got airtight joints. It was very cool. This jig uses a 9-degree cutting angle. Woodworking books say that 9 degrees is intended more for soft woods than hardwoods (which use a 7-degree angle) but I thought it a good compromise. You can build this jig entirely by hand, but I cheated and used a table saw for a couple of the precise angle cuts. Let your

conscience be your guide. One of this jig’s peculiarities is that you’ll sometimes have to cut right on the pencil line. As designed, this jig works best with Japanese-style Ryoba saws on material from 3⁄ 8” to 3⁄ 4” thick. Use the saw’s ripping teeth when making your cuts. You could modify this jig to accommodate Western saws, but you’d have to take a lot of the set out of the teeth so you didn’t tear up the faces of the jig. The set of a saw’s teeth basically allow you to “steer” a blade through a cut. This jig does all the steering. You just have to press the gas.

D OV E TA I L J I G

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2 1

START WITH A SANDWICH

Begin by sandwiching three pieces of wood. This part is made from two pieces of 3⁄ 4" x 6" x 36" plywood with a piece of 1" x 1" x 36" solid wood centered between. Use a spacer to index the center precisely in the middle of the larger panels. Glue and nail the sandwich together.

ADD AN ABRASIVE

Using contact cement, attach 120-grit sandpaper to the same side of the inside channel, on both sides of the jig.

1 30

CUTTING THE ANGLES

REMOVE THE WASTE

Set your saw’s blade to 9 degrees and crosscut the end of the sandwich while it’s flat on the saw. Next, tilt the blade back to square and set the miter gauge to 9 degrees as shown (above). You can use the angled end of the sandwich to set your miter gauge. Lay out a center line down the middle of the sandwich and mark from the end of the line about 31⁄ 2". Use a sliding t-bevel to transfer the angle to the flat side. This yields a jig that will let you cut dovetails in material as narrow as 3" wide. Any narrower and you’ll have to shorten the jig. Lay the extrusion flat on the saw table and cut to the line. The jig will be a little narrower on the other side but that’s OK.

Attach the 1⁄ 2" x 41⁄ 4" x 6" faces to the ends of the jig with nails and glue. Use a Ryoba saw to start the cuts to open up the channels in the jig (above and right). Use a coping saw to cut out the part of the ends that cover the little channels in the sandwich (far right). Note the blade is perpendicular to prevent binding on the jig itself. Clean up with a rasp and sandpaper.

8

7

3

9

QUICK CLAMPING

CUTTING TAILS AND PINS

Doctor up a couple of 1⁄ 4"-#20 T-nuts by pounding over the set tines and grinding off a little of the threaded barrels. With some two-part epoxy, attach some 1⁄ 8"-thick wooden pads to the face of the T-nuts. When the epoxy is set, sand the pads to fit the T-nuts. Run your thumbscrews through the threaded inserts and attach the T-nut/ pads to the thumbscrews with some threadlocking compound (available at any automotive parts store).Finish the jig by attaching something slick to the faces. I used some UHMW (Ultra High Molecular Weight) plastic self-stick sheeting. It’s 1⁄ 16" thick, and if you wear out the material on a face, you just peel off the old material and stick on some new. You could just as easily use some wax on the wood faces. You’ll just have to sand them flat, eventually.

Using the jig couldn’t be simpler. I cut tails first. That’s a personal choice, but this jig will work well whether you’re cutting tails or pins first. The layout is a little simpler than when going “free-hand.” All you do is mark the depth of the cut with a marking/cutting gauge and lay out the spacing for the tails on the end of the board. Use the pencil marks to cut out the tails (above) and when you get the waste cleaned out, use the tail end of the board to lay out the pins (right). Use a sharp pencil for marking, then cut out the pins. Check the fit of the pins to the tails using a piece of scrap as a hammer block across the whole joint. If they’re a little big, do some fitting with a four-in-hand rasp. The joint should be snug, but not so tight that it cracks the tail board when hammering the joint together.

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4

5

6 THREADED INSERTS

Lay out and drill 5 ⁄ 16" holes as shown in the diagram. These accommodate the threaded inserts for the set screws. Attach the threaded inserts using a hex key/Allen wrench.

10

Supplies Lee Valley 800-871-8158 2 • 1⁄ 4”-20 flanged insert nuts # 00N10.13, $.22 each. Ried Supply 800-253-0421 2 • 1⁄4”-20 thumbscrews #MIT88, $1.99 each. Woodcraft 800-225-1153 3”-wide UHMW self-stick tape #16L65, $21.99/roll

Dovetail Jig NO.

❏ ❏ ❏

ITEM

2 1

Sides Center block

2

Faces

DIMENSIONS (INCHES) T W L

3⁄4” 1” 1⁄ 2”

6” 1” 41 ⁄ 4”

MATERIAL

36” 36”

Plywood Poplar

6”

Plywood

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CHAPTER • 27

Shop-Made Mortise Jig BY GLEN D. HUEY

Reproduction furniture is my main focus in woodworking, so I think one of the most important construction joints is a mortise-and-tenon joint – and not simply the use of a stub tenon, but a full-blown tenon that ranges between 1” and 11⁄4” in length depending on the project and if there’s adequate depth in the material. Due to the number of these joints I make, I have a dedicated mortising machine. But if you need to create a mortise and tenon and you don’t have a dedicated machine to use, whip up this simple jig from a few scraps of wood and use a plunge router, a properly sized guide bushing and an upcut-spiral router bit. (You can use a straight router bit, but an upcut bit lifts waste material out of the mortise, so it makes a cleaner cut.)

Make a Slot for a Guide Bushing The first step in building this jig is to create a slot in a piece of 1⁄2” plywood to guide the bit’s location as you plunge into the workpiece – plywood’s stability makes it a better choice. Don’t create a slot that matches the router bit size; you need to match the slot to the guide bushing’s outside diameter. Select a bushing with a diameter that’s larger than the router bit. For standard 3⁄4” material, I use a 3⁄4”-outside-diameter bushing for two reasons; this diameter is a standard drill bit size and the slot matches the thickness of the stock with which I’m working. When working with 3⁄4” material, select a plywood scrap that’s about 33⁄4” wide and at least 12” long, then establish a centerline. Chuck a 3⁄4” 1 32

JOB-SPECIFIC TOOLING. A mortise-and-tenon joint is one of the strongest, most useful joints in woodworking. With scraps from the waste bin, you can create a jig that does the job and is simple to use.

12"

3⁄4"

guide bushing

1⁄4"

router bit 33⁄4"

X X +1⁄2"

MORTISE JIG

drill bit into a drill press. To determine the length needed for your specific mortise when using a 3⁄ 4”-outside-diameter bushing and a 1⁄ 4” router bit, add 1⁄2” to the finished length of your required mortise. The addi-

tional opening allows for the differences between the router bit and the guide bushing. Next, lay out the final measurements on the centerline of the plywood. Position a fence so the center point of

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the drill bit aligns with the centerline on your plywood. Drill the two end holes first, making sure to position the outside diameter of the bit’s cut with the outside location of the layout. Once the ends are established, remove the additional waste with your drill bit while keeping the workpiece tight to the fence. When finished, the slot has smooth sides. (You can touch up the sides with a rasp or file if you need to.)

Side Pieces Complete the Jig For step two, position two additional scrap pieces on either face of the material to be mortised while holding one end of each piece flush with the end of the workpiece. Next, clamp the three pieces into a bench vise. These scraps or side pieces should be nearly as long as the slotted top piece of the jig. The key to building this jig straight and centered is in the final step. Lay out the mortise on your workpiece; I find it best to do the layout work using the overall length of the slot, keeping in mind that my finished mortise will be 1⁄ 2” shorter. Position the plywood piece on the three pieces in your vise, align the slot with the layout lines at the top and bottom, and with the edges of the workpiece looking side to side. Once you’ve got the slotted piece properly positioned,

EVERYTHING HELD SECURELY. Once the parts of the jig are positioned around the piece to be mortised, add screws through the top to complete the jig.

add a couple clamps to hold everything in place. Attach the slotted top to the two side pieces with #8 x 11⁄4” screws – two screws per side. Counterbore the holes for the screws. This is not the time to split or crack the side pieces. Pull the assembly from your vise and remove the workpiece. The fit should be snug so it will take some muscle to remove the workpiece from the jig.

Plunge a Mortise Set up your router with the guide bushing and a 21⁄2”-long router bit. You’re now ready to work. A bit this long allows you to plunge a mortise just over 11⁄4” in depth into the workpiece after passing the jig’s 1⁄2”-plywood top. Match the jig’s opening to the layout lines on your workpiece and clamp the two together in a vise or with other clamps. Zero out the router bit by plunging down (with the power off and the router unplugged) until the bit touches the workpiece, then lock the plunge mechanism. Use the router’s depth stop to set the plunge depth. The base of the router sits securely on top of the jig and the bushing, which fits snugly in the slot, adds to the overall stability. To create the mortise, release the locked plunge mechanism and pull the router setup tight to one of the ends. With the bit standing above the workpiece, start the router and hold tightly against the slot’s end as you plunge to full depth. Allow the router bit to retract from the hole, slide the router to the opposite end and plunge a second hole. To remove the material for the balance of the mortise, repeat the plunge action, each time positioning the router setup over an unexcavated area. Once most of the waste is removed and no section remains that bridges the two sides of your mortise, return to one end of the slot, plunge to the bottom of the mortise and make a pass along the entire length to clean and straighten the sides. Make it a point to travel the length while holding the bushing firm to one side, then make a return pass holding tight to the opposite side. The

YOU CHOOSE THE LENGTH. The overall length of your mortise is determined by the slot cut into the jig’s top. Make sure to compensate for differences between the bushing and router bit.

TWO FINISHING PASSES. Once the plunging cuts are completed, finish the mortise with a pass along both faces of the slot. This last step smooths and cleans the slot.

result might be slightly wider than the 1⁄ 4” router bit, but because you make the mortise section of the joint first then match the tenon, this won’t be an issue. This jig is easy to build and can be used repeatedly with consistent results. The only decision you’ll need to make is should you round your tenons to match the mortise, square the mortise ends to match the tenons or create tenons with wiggle room – not snug to the mortise’s rounded ends. I always opt for wiggle room.

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CHAPTER • 28

Mortising Jig for a Router BY STEVE SHANESY

Most woodworking jigs fall into two categories: Those you use once and then pitch, and those you use over and over again. This mortising jig falls into the latter group. And if longevity and amount of use a jig gets is any indicator of value, consider this jig worth its weight in gold. More than 20 years ago I made a version of this jig as a companion to my then-new plunge router (shown in the photo). The concept was shown in an early woodworking book by The Taunton Press by venerable woodworker Tage Frid. Both the jig and the router continue to see service in my shop, although I made a new jig for this article and added a couple new features. Over the years, I’ve cut mortises by hand, with this jig and using a variety of benchtop mortising machines. I find one big advantage of router-cut mortises is the smooth wall of the mortise itself, which is certain to produce a stronger glue joint than those made with a chisel or mortising machine. The smooth surface is especially advantageous given the cross-grain condition of typical mortiseand-tenon joints. The jig also sets up quickly and provides a high degree of repeatable accuracy. Combine the unit with an aftermarket router fence such

1 34

as the Micro Fence (www.microfence. com) and set-up time is even faster. One downside to all router-cut mortises is the round, rather than square, ends produced. The problem is overcome most easily by rounding over the square corners of the tenons using a file. Once the mortise location is drawn on a part, you secure your work in the jig using the built-in clamps. Lower the router bit to the height of the part and adjust the router fence to align with the mortise location. The forward and backward travel of the router is quickly limited by the jig’s adjustable stops on the top of the jig’s side. Set the depth of plunge on the router and you’re ready to cut your mortise. Remember to pull the router toward you when making cuts; this uses the rotation of the bit to hold the router fence to the jig’s side.

Jig Construction Building the jig is simple and should take an afternoon. When done, you’ll be able to rout mortises for a set of table legs, for example, in less than 15 minutes, including set-up time. Buy your hardware before building the jig. It is easier to drill the holes and install the barbed inserts in the side of the jig before assembly. These are placed

in a 3⁄ 8” hole that’s 2” deep on the top edge of the side.Take care to drill in the center of the plywood. Next, drill out a 1⁄ 1 4” hole in a length of ⁄ 2” dowel that will both plug the hole and further secure the insert — yet allow the bolt to access the buried insert. Now drive in the threaded insert. It’s a good idea to place the side in a vise to prevent the plywood from splitting during this operation. When done, chase the hole with a 1⁄ 2” drill bit to the depth of the insert so the dowel will fit the hole. Next, glue the dowel in place. Go easy on the glue so you don’t fill the inserts threads with glue. Apply the hardwood edgebanding on the tops of the jig’s sides. When making the bottom, first glue up an oversized double-thickness plywood blank. Cut it to final dimension, making sure your table saw blade is dead square to the saw table. This will ensure your side parts will be square to the part you are mortising. When the bottom is ready, glue and clamp the two sides in place. Keep the bottom edge of the sides in line with the bottom surface of the bottom part.

Clamping Mechanism While this assembly is drying, make the parts for the clamp mechanism and the adjustable stops. Use hardwood and make them to the shape and dimensions given in the diagrams and cutting list. Make longer lengths that can later be cut to final size. It’s both safer and faster. Use a router in a router table to make the adjustable stops. First cut them to width, then rout the groove below so

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MORTISING JIG FOR A ROUTER

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Rout mortises making stepped cuts for safety. Each pass should be 1⁄ 4" to 3⁄ 8" deep. Pull the router toward you so the bit rotation forces the router’s edge guide to the side of the jig.

Set-up can be a snap. With the bit set to just clear the work piece, set the stops for the router, then adjust the router’s edge guide to the mortise layout lines.

that it is centered on the stock. Check the fit on the jig side. You want it to move freely but without side-to-side play. When done, rout the 1⁄ 4” slot. If you didn’t move the router table’s fence after routing the groove, it should be centered on the part. Take the jig out of the clamps, install the stops, bolts and knobs. Bore the holes for the clamp mechanism in the clamping blocks and jig sides. Also, install the threaded inserts in the clamp blocks. Complete the jig by installing the clamp assembly in the jig.

Tips on Use When using the jig, be sure it is securely fastened to a bench or held in a vise. You will also need to clamp a stop block on the inside of the jig’s side to use as a gauge for placing successive parts in the exact same location. Remember to make multiple passes when routing your mortises. I’d recommend no more than a 3⁄ 8”-deep cut at a time when using a router bit in the 3⁄ 1 8”- to ⁄ 2”-diameter range. And as for bit selection, an up-spiral straight bit is best because the spiral design evacuates the waste up through the flutes in the bit.

STOP DETAIL

CLAMP DETAIL

Mortising Jig NO.

❏ ❏ ❏ ❏ ❏ ❏

1 36

2 2 2 2 2 1

ITEM

Sides Bottoms Edge bands Stops Clamp blocks Dowel

DIMENSIONS (INCHES)

MATERIAL

T

W

L

¾ ¾ ¼ ½ 2 ½

5 3½ ¾ 1¼ 2

26 26 26 7 4

Plywood Plywood Maple Maple Maple Dowel stock

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CHAPTER • 29

Biscuit Joinery Basics BY CHRISTOPHER SCHWARZ

My first woodworking class years ago was all about hand-cut joints. We cut mortises, tenons, dovetails, half-laps, bridle joints, you name it. All with hand tools. It’s a lucky thing a coping saw doesn’t make much noise because while cleaning out my 114th dovetail pin I overheard a classmate talking about biscuits. Biscuits, he told us in hushed tones, are a faster and easier way to join wood. But some people, and he looked up at that moment to see if our instructor was looking, think that biscuits are cheating. Well that was enough for me. I had to find out what all the fuss was about. As it turns out, biscuit joinery is, in actuality, cheating — the same kind of way that nuclear weapons are cheating. Like ’em or not, they get the job done faster than anything else out there. Biscuits aren’t right for every situation (chairs come quickly to mind) but for many projects, biscuit joints are just the thing. First, they’re strong. Lamello, the inventor of biscuit joinery, has done extensive stress tests on the joints. In one of these tests the scientists joined two

The three most common sizes of biscuits: a #0 (the smallest), a #10 and a #20.

Biscuit joiners cut a semicircular slot that’s the perfect size for a biscuit — essentially a manufactured loose tenon. To illustrate how the machine works, we cut a slot in some Lexan,a tough polycarbonate plastic. Though this isn’t a common application for the tool, it handled the job with surprising ease.

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Biscuiting a partition in the middle of a panel

The best way to biscuit a partition into the middle of a panel is to use the partition itself as a fence for your biscuit joiner. Here’s how: Mark on the panel where you want the partition to be placed.

Lay the partition flat on the panel and against the line you marked. Clamp the partition and panel to your bench. Mark on the partition where you want your biscuit slots to go. There is no need to mark the panel beneath it.

Now remove the fence from your biscuit joiner. Place it flat on the panel and cut the slots in the partition.

pieces of beech end-grain-to-end-grain using a #20 biscuit. This is just about the weakest joint I could imagine. Then they had a machine grab each end and pull the thing apart. It took an average of 972 pounds of force to destroy the joint. Not bad for a little wafer of beech or birch. Second, they’re fast joints to make. We checked the amount of time it took to make several common joints for face frames. The winner was the pocket

screw, but that’s because there’s no clamping time. Take the clamping time out and biscuits and pocket screws are a tie for the fastest method. Finally, they’re safe and easy to use. It’s difficult to hurt yourself with the machine, and injuries are rare. In fact, I know of only two ways an injury can occur. First, the tool slips or kicks out of a cut and your left hand gets chewed up before the blade retracts. Or second, you plunge the biscuit joiner before you turn it on. The tool walks into your hand that’s holding the piece and up your arm. I’ll show you how to build a simple jig that will quickly clamp narrow pieces and make it almost impossible to hurt yourself. If you’ve never used a biscuit joiner, it probably will take you about five minutes to learn the basics. That said, there are some tricks to ensuring that all of your joints are perfectly lined up. Because the tool is so fast, it’s easy to get lazy and a little sloppy.

ATTACHING A TABLETOP TO AN APRON One

The Basic Basics Biscuits can add strength to a joint, such as when you join a table apron to a leg. Or they can be used as an alignment aid, such as when you glue up a slab using several boards or you need to glue together veneered panels. The biscuits won’t add strength here, but they will keep your parts in line as you clamp. In a

solid-wood panel, the biscuits reduce the amount of time you spend leveling your joints. In veneered panels, biscuits keep your parts in line so you don’t end up sanding through the veneer. When making a biscuit joint, first put the two parts together and decide how many biscuits you need for that joint. A basic rule of thumb is to place your first biscuit 2" from the edge and then every 5" to 7" or so, though the spacing is really up to you. Draw a line across the joint at each spot where you want a biscuit. Set the fence on your biscuit joiner so the biscuit will be buried approximately in the middle of your material (for example, if you’re working with 3⁄ 4"thick wood, set your biscuit joiner for a 3⁄ 8"-deep cut. Don’t worry about being dead-on in the middle. If you cut all your joints on one side, say, the face side, everything will line up). Select the size biscuit you want to use and dial that into your tool. Use the biggest size you can. Clamp one of your parts to your bench. Line up the line on the tool’s fence or faceplate with the line on your work. Turn on the tool and allow it to get up to full speed. Plunge the tool into the wood and then out. Repeat this process for the other side of the joint. Now glue up your joint. There are at least two ways of doing this. You can put glue in the slots and then insert the biscuit, or you can put glue on the biscuit

of my favorite tricks with a biscuit joiner is using it to cut the slots for tabletop fasteners. Set the fence for 1⁄ 2" (you want the slot to start 7⁄ 16" down from the top of the apron) and make your cuts on the inside of the apron (you can do this after the table is assembled). The “Z”-shaped fasteners now slip into the slots and can be screwed to your tabletop.

1 38

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Now turn the biscuit joiner on its head and cut the slots in the panel. Use the layout lines on the partition and the centerline on the bottom of the tool to properly line up the biscuit joiner.

and insert it in the slot. For small projects, paint half the biscuit with glue and insert it into one of the slots. Then paint the other half of the biscuit and clamp your pieces together. This method produces clean joints with minimal squeeze-out, but it’s a bit slow. When assembling big projects, I like to put the glue in the slots first using a bottle designed for this task. Squirt a dab of glue in all your slots and use a spare biscuit, piece of scrap or brush to paint the edges. Put the biscuits in the slots and clamp up. The downside to this method is it’s easy to use too much glue, and you’re liable to get more squeezeout. No matter which method you use, be sure to go easy on the clamping pressure. It’s easy to distort a frame made with biscuits. If you’re using a regular yellow glue, clamp the project for at least 30 to 45 minutes before taking it out of the clamps.

Where to Use Biscuits Making the biscuit slot is easy. The tricky part is knowing when to use biscuits and how many to use. Here are some situations when you should be careful: Long-grain joints: Many people use biscuits to join several narrow pieces into a panel, such as a tabletop. Biscuits help align the boards so they don’t slip as

much when you clamp them. However, don’t let anyone tell you that the biscuits make the joint stronger. In long-grain to long-grain joints, the glue is stronger than the wood itself. So biscuits here are only an alignment tool. Also, be careful to place the biscuits where they won’t show after you trim your part to finished size. Once I raised the panel on a door and exposed half a biscuit. That panel had to go in the trash. Face frames: Biscuits are just right for face frames as long as your stock isn’t too narrow. A #0 biscuit will only work with stock as narrow as 23⁄ 8". Any narrower and the biscuit will poke out the sides. To join narrow stock you need a biscuit joiner that can use a smaller cutter (such as the Porter-Cable 557 or Lamello Top

20) or a tool that cuts slots for mini biscuits from Ryobi or Craftsman. Continuous-stress joints: Biscuits are strong, but I wouldn’t build a kitchen chair with them. The joints in chairs, especially where the seat meets the back, are subject to enormous amounts of stress. Call me old-fashioned, but I’d use a mortise-and-tenon joint. With polyurethane adhesives: We like poly glue quite a bit, but you must remember that biscuits swell and lock your joint in place by wicking up the water in your white or yellow glue. Poly glues have no moisture in them. In fact, these glues need moisture to cure. If you want to use poly glue with biscuits, dip your biscuits in water before inserting them into the slot. The water swells the

Biscuiting an apron to a leg

If you’re going to use biscuits to attach a leg to a table apron, then you really should use two biscuits stacked on top of one another. This joint, according to experts and scientists, is nearly as strong as a mortise-and-tenon joint. The other challenge with this joint is you are going to want to offset the apron so it joins the middle of the leg. Here’s the best way to do this. First determine what your offset is. I wanted my aprons to sit 1⁄ 2" back from the legs. Now get a scrap piece of wood that is the same thickness as the offset. Put this block of wood on top of your apron and set the fence on your biscuit joiner to make the first cut. Make the cut on the apron.

Now cut the biscuit slot on the leg without the spacer. When that’s done, go back to your apron and adjust the fence to make the second biscuit slot.

Finally, cut the second row of slots on the leg without the spacer. When you’re done, you’ve got a double helping of biscuits that’s ready for some glue.

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Biscuiting Miters

The fence on the Porter-Cable 557 allows you to biscuit your miters with the fence on the outside of the joint — a nice feature.

You can biscuit miters without using your fence by clamping the two joints together.

If your fence is adjustable only between 0° and 90°, you can cut the joint on the inside of the miter. Just be careful when positioning your tool.

Or, if you have a fixed 90° fence on your tool, you can clamp them together this way to cut your slots.

Biscuit Joinery Clamping Jig NO.

LET.

ITEM

2

A

Bed

3⁄

4"

Cleat

3⁄

❏ ❏

1

B

DIMENSIONS (INCHES) T W L

MATERIAL

181 ⁄ 2" 181 ⁄ 2"

Ply

4"

21 ⁄ 2"

Ply

181 ⁄ 2"

1

C

Fence for stiles

1⁄

2"

3" x

13"

Ply

1

D

Fence for rails

1⁄

2"

3"

71⁄ 2"

Ply

1

Mitering guide

3⁄

4"

8"

15"

Ply

1 40

biscuit and activates the poly glue. Building tables: If you’re going to build a table using your biscuit joiner, use two stacked biscuits to attach the aprons and stretchers to the legs. This might mean making your aprons 7⁄ 8" thick. See the photos below for an easy way to get the apron in the right place and two biscuits into your joint. In fact, whenever you’re joining thick stock it’s a good idea to add an extra biscuit. With 1⁄ 2" plywood: When using a biscuit joiner to join pieces of 1⁄ 2"-thick plywood, you might have trouble with the biscuits “telegraphing” their shape into the surface of your material. Use #0 or #10 biscuits with 1⁄ 2"-thick material and go a little easy on the glue. Fence or no fence? Some woodworkers always rest the tool’s fence on the work to control how deep the cut is; others prefer to take the fence off and let the tool’s base ride on their bench or a table. There are advantages to each approach. When you take the fence off and use your bench as the reference surface, you have a large flat area for your tool to rest against and sniped boards won’t throw off your joiner. However, you have to watch for sawdust on your bench and work with all your parts face-down on your bench. Advocates of the fence approach say it’s easier and more accurate to work with your parts face-up on your bench. But you have to ensure your biscuit joiner is square to your work. If you lift up or press down on the tool during the cut, it could throw off your joint. Try each method and see what works best for you.

Quick Jig Speeds Your Work There aren’t a lot of jigs and fixtures for your biscuit joiner. However, building this jig will make the tool easier and safer to use. When I first started using biscuit joiners, I held the wood with my left hand and the tool with my right. After my grip failed me a couple times, I became an advocate of clamping your work in place. But clamping takes time. This jig makes clamping quick and easy. The quick-release clamps allow you to fix your work in place in a second or two

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Where Do Biscuits Come From? As important as the tool itself is the lowly biscuit. These football-shaped pieces of wood are a bit of an engineering marvel. Out of the box, biscuits are about .15" thick, and they fit into a slot that’s about .16". When the biscuit comes in contact with the water in your glue, it swells up, locking the joint in place. To ensure the joint is strong, the grain direction on biscuits runs diagonally. This prevents your joint from splitting and gives you, in the worst case, a crossgrain joint. But just where do these little suckers come from? Kathleen Oberleiter, the dealer sales manager for Lamello, says her company has one plant in Switzerland that produces biscuits for Europe and the United States. In addition to producing biscuits under its own name, she says Lamello also makes the same quality biscuits for Makita and Black & Decker (and Black & Decker’s sister company, DeWalt). Lamello (800-252-6355) employs two people whose job is to find the perfect European beech trees for making biscuits. They look for trees that are at a particular stage of growth and choose those for harvesting. The trees are debarked, cut into thin panels and kiln-dried. When the panels are dry the biscuits are stamped and compressed from those panels. Lamello brags that all its biscuits are within one-tenth of a millimeter in thickness and with a moisture content between 8 and 10 percent. Here in the United States, Porter-Cable (800-487-8665) started making its own biscuits in Jackson, Tenn., in the mid-1980s, according to company officials. Then the company concluded it would be better to have

(with almost 300 pounds of clamping pressure) and it gives your biscuit joiner a bed to ride on. Why is that important? You see, if you retract or remove the fence on your tool, the tool is designed to cut a slot in the middle of a 3⁄ 4"-thick board when resting on a flat surface. So with this jig you don’t need to set your fence. You simply clamp your wood in place, mark where you want the slot, put your tool on the bed and plunge. This jig also makes your cuts more

another company make the biscuits using Porter-Cable’s tooling and equipment. Now Hill Wood Products of Cook, Minnesota, makes all of Porter-Cable’s biscuits. The company also makes Ryobi’s face frame biscuits. In fact, Hill Wood’s plant is the only major producer of biscuits in this country and makes between 60 percent and 70 percent of the biscuits sold in the United States, says Hill Wood President Steve Hill. Since his company started making biscuits for Porter-Cable, Hill says his company has upgraded the original equipment three or four times and can now easily make 1 million biscuits a day. Instead of beech, Hill Wood makes biscuits using Northern white birch from Minnesota, most of which comes from within a 150-mile radius of the plant. The trees are sawn using special equipment and then dried to a moisture content between 6 percent and 8 percent. Then the strips of birch are transformed into biscuits by the company’s machinery. Interestingly, Hill says Hill Wood does not compress the wood for its biscuits and relies on the moisture in the glue to swell the biscuit and lock the joint tight. The company’s equipment is capable of compressing the biscuits, but Hill says he’s found that wood can compress unevenly, resulting in biscuits of different thicknesses. Hill Wood cuts its biscuits within 5-thousandths of the optimum thickness. So how does birch compare to the European beech? Hill says beech is actually a little harder and the grain is a bit tighter than in birch, but that it’s real close. “The glue or the

accurate because it ignores snipe on the ends of your stock. If you use the fence on your biscuit joiner when building face frames you can get in trouble when the end of the board is sniped. Because of the snipe, your tool won’t cut the slot in the right place and your joints won’t be flush. With this jig, all you have to do is remember to put all your pieces faceside down on the jig and keep it free of sawdust. Because the tool rides on the jig and not the work, your slot is going to be

wood is more likely to fail than the biscuit,” he says. Freud (800-334-4107), a major player in the biscuit market, has its biscuits made by a Spanish firm that makes biscuits for many other firms, according to Jim Brewer, vice president of operations. Freud’s biscuits are made of beech and are compressed, he says. Biscuits sold by Ryobi (800-323-4615) are manufactured in Minnesota from beech and are compressed, company officials say. Kaiser biscuits, which are made in Austria from beech, have been distributed in the United States for the last five or six years by Practical Products Co. (800-8478839) of Cincinnati, Ohio, according to Donald Baltzer, company president. Kaisers are well thought of in Europe and are compressed during manufacturing.

Hermann Steiner, inventor of the Lamello joining system.

exactly where you need it. I also made an attachment for this jig that guides the biscuit joiner when cutting slots in miters. This attachment keeps your tool on target and prevents it from kicking left as you plunge. Building the jig takes less than 30 minutes. The most important part is the bed itself. You want it to be as flat as possible. Glue two pieces of 3⁄ 4"-thick plywood together and check the “sandwich” for flatness with a straightedge. Then nail another piece of plywood on B I S C U I T J O I N E RY B A S I C S

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the bottom of the jig’s front edge so the jig hooks over your bench. Nail and glue two strips of 1⁄ 2"-thick plywood in the locations shown in the diagram. Then screw the clamps in place. Let the glue dry before you go to work; engaging the clamps at this point can tear your jig apart.

Troubleshooting Not much goes wrong with biscuit joinery, but here are some of the troubles we’ve run into and how to remedy them. Sometimes when you get in a hurry your biscuit slots aren’t aligned. The joint will either be whopper-jawed or impossible to clamp shut. Using a ruler, figure out which of the slots is off (it might be both). Glue a biscuit into the botched slot and let the glue dry. Then trim the biscuit flush to your material and cut your joint again. When your biscuit joiner bogs down and burns the wood, it’s trying to tell you something. Usually your blade is gummed up with resin or it’s dull. Remove the blade and spray it with an oven cleaner. If that doesn’t help, replace the blade. Probably the weakest feature on most biscuit joiners is the dust collection. Typically, the tool tries to shoot the chips out a small port and into a cloth bag. This usually works for about half a dozen biscuits, then the port gets clogged and dust sprays everywhere when you make a slot. Sometimes this is a sign that your bag is getting old and frayed. The frayed ends cling together and the chips back up into the port and then get clogged. If your bag is old, first try turning it inside-out. If that doesn’t help, just get an adapter to connect your tool to a shop vacuum. That will solve your problem.

Biscuit Jig

This jig is useful for two reasons. First, it will make your tool more accurate. You use the plywood base to guide your tool. That way if there’s any snipe on the end of the board, your biscuit will still end up in exactly the right spot. Second, it will make your work a whole lot faster. The quick-release clamps on this jig (which supply hundreds of pounds of clamping force) will keep you from clamping each piece to your bench, which slows you down. If you’re one of those people who holds your face frame parts down with your hand as you cut them, you’ll find this jig is just as fast as that method, and your work is a lot less prone to slipping.

The beauty of this jig is that it holds both a rail and stile in place for cutting. You can cut one right after the other if you please, or cut them one at a time.

If you cut biscuits to join a mitered frame, this jig is quite useful when you add the 45-degree spacer shown in the photo above. The spacer helps guide the tool and prevents it from kicking to the left, something the biscuit joiners are prone to do in narrow stock

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CHAPTER • 30

Box Joints Visit most any antiques store or flea market, and you’re sure to see stacks of old wooden boxes marked with the logos of by-gone businesses. Small boxes for cigars, big ones for fruit and lots of in-between sizes. All are assembled at the corners with interlocking square pins or fingers – the box joint. The box joint is a sort of square-cut through dovetail. It’s used in the same situations as the dovetail – assembling boxes, drawers and casework. It has pretty fair mechanical strength, but what it does is create a tremendous amount of gluing surface to create a stout joint. You may know this joint as a finger joint. I use that name for an interlocking edge-to-edge joint that’s cut with a special bit. Look at the box-jointed object above. The end of the piece on top is comb-like, with uniform pins and slots. The pins on this board fit into the slots on its mate and vice versa. So making the joint is all about cutting a series of slots to form a series of pins. You can cut the slots in several ways. The most obvious is on the table saw with a dado cutter. Make a little jig to attach to the miter gauge – or an independent one that rides in both miter slots – and go to town. But the tablemounted router does a clean job, too, and in the same amount of time.

The Box-joint Jig Whether you do the work on the table saw or the router table, the process is the same, and so is the jig. What the jig does is position the work so the cuts are

Photo by Al Parrish

B Y B I L L H Y LT O N

separated by pins that are the same size as the cuts. The critical element is a little wooden “key.” The key is custom-made, so it fits the cut exactly. It’s attached to the jig in a way that permits lateral adjustment so you can control the spacing of the cuts. The box-joint jigs I’ve made are miter-gauge-like, with a separate facing

into which the key is glued. The jig itself can be any scrappy old thing, so long as it’s accurate, with the back perpendicular to the saw or router table. You can change the facing as dictated by wear and use. While you probably can get acceptable results cutting 1⁄2"-deep slots on a jig set up for a 3⁄ 4" depth-of-cut, splinterB OX J O I N T S

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I made an independent box-joint jig for the table saw (shown at right) that rides in both miter slots and has the capacity for blanket-chest-size parts. Candidly, I haven’t used it on anything bigger than roughly 2'-square, 8"-high drawers. The particulars are shown in the illustration at right. To make the jig, select suitable materials from your scrap pile. I used sheet goods (plywood and MDF, primarily) for most parts because they’re stable, and because I always seem to have odd scraps around. The “key� is the one part of the jig that should always be a hard wood. It’s subjected to a lot of wear, and

The jig I use on the table saw rides in both miter-gauge slots. The adjustable facing, into which the key is glued, is cut from a scrap of 1 â „ 2" MDF.

On the router table, I use a small version of the jig. My tables don’t have miter-gauge slots, so I align the jig with the selected bit in the slot in the jig base. Then I set a thin plywood strip against either edge of the jig and clamp them to the tabletop.

Step photos by the author

ing or “blow-out� is likely to occur as the bit exits a cut. The backing is 1⠄ 4" above where the tip of the blade or bit cuts through the workpiece, which is as good as no backing at all. While it’s possible to reuse a facing, it may be better to use a fresh pair of slots – not necessarily a fresh facing – for each new job. (By sliding the facing fully right for one job, then fully left for another, and then rotating it 180° and repeating, you should be able to use a single facing for at least four jobs. Then you can trim it down and drill new mounting holes and use it for a couple more.)

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if it’s too soft, it will deform and throw off the accuracy of your cuts. The pins won’t mesh, in other words. Except for the replaceable facing, glue and screw the parts together. My router tables are devoid of mitergauge slots. So for router-table use, I have a small box-joint sled, shown below right. To guide it, I clamp hardboard or plywood strips to the tabletop – the sled is then trapped between them. These fences allow the workpieces to extend beyond the jig’s edge. You can cut joints on wide stock as easily as on narrow boards.

Using the Jig The initial step is to reconcile the slot width and the width of the workpieces. You really want to begin and end each array of pins with a full pin or a full slot. To accomplish this, the width of the boards should be evenly divisible by the slot width. If this isn’t the case, then it’s best to change either the slot width or the joint width. A corollary is that a joint layout that begins with a full pin and ends with a full slot mates two identical pieces. Therefore you can cut both at the same time. All four parts of a box can even be cut simultaneously. If the layout begins and ends with a full pin, you must cut the sides and ends in sequence. I’ll explain this in just a few more paragraphs. It’s worth pointing out that the stock thickness has no bearing on the pin thickness. You can use 1⠄4" pins on 3⠄4" stock, for example, or 1⠄2" pins on 3⠄ 8" stock. But it does impact the pin length. The blade or bit elevation must equal the stock thickness (plus the jig base thickness, of course). Set up the cutter and jig. Install the dado cutter in the table saw, combining the blades and chippers needed for the desired cut width. In a table-mounted router, use the correct diameter of straight bit. Adjust the height. The easiest way to set this is to lay a scrap of the working stock on the jig base, park it by the cutter and raise the cutter to that height. The first cut creates a slot in the fac-

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ing for the key. What I do is offset the facing to the left to begin. Lock the facing and cut a slot, as shown on the next page. The next step is to make a key that just fits the slot. The key must be the exact width of the slot, but no taller. So your key is on the order of 1⁄2" wide and 3⁄ 8" thick, maybe smaller, maybe larger. I rip a stick close, then hand plane it (it’s occasionally unavoidable) to fit. When it fits, I clip it in two and glue one piece into the slot. To adjust the jig for the joinery cuts, set the second piece of the key against the cutter and slide the facing toward it until its key touches the loose one. The gap between the cutter and the key now equals the bit’s diameter, as shown in the photo below. Cut a test joint. Stand a stacked pair of samples in the jig, edges snug against the key. Cut a slot. Move the stack, fitting the slot over the key. Cut another slot. Repeat the process until all the pins are formed. Fit the joint together (offset them if need be to align pins with slots). If the pins won’t go into the slots, the key is too far from the cutter. If the pins are loose in the slots, the key is too close to the cutter. Rather than slide the facing left or right a “hair,” a “tad” or a “skoshe,” use your dial calipers. Measure a pin and a slot. The amount you move the facing is half the difference between the pin width and the slot width. You can use a feeler gauge to make what is most likely a minute adjustment. • If the pin is bigger than the slot, move the key closer to the cutter. Set a block against the key and clamp it. Loosen the facing, slip the feeler gauge between the block and the key, and relock the facing. Remove the block. • If the slot is bigger than the pin, move the key away from the cutter. Clamp the block to the jig with the feeler gauge between it and the key. Loosen the facing, remove the gauge, and reset the facing with the key tight against the block. Then remove the block. A second set of cuts will confirm the accuracy of your adjustment.

Kerfing the adjustable fence for the key is the first step in setting up your box-joint jig. Note the two kerfs from a previous job to the right of the blade. It’s best, I think, to set up fresh for each new job.

Make a key strip, hand-planing it to achieve a tight press-fit in the kerf. Cut the strip into two pieces: one is the key, the second is a setup gauge.

Stand the work on end, tight against the key. Push the jig across the cutter and make the first slot.

After each cut, step the work to the right, fitting the freshly cut slot over the key. Each cut matches the width of the key, and leaves a pin of the same thickness between slots. Step-and-repeat until you’ve cut pins across the full width of the work.

Two boards stacked

In production mode, you can cut more than one board at a time. Stack the sides and cut the pins across an end. Then hold the ends against the sides to continue the cutting sequence across them. Cutting the full layout across both pieces isn’t necessary to test the fit. If the setup is significantly off, fitting three or four pins will expose it. If those pins mesh nicely, cut more of them and refit the joint.

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One note about fitting the joints: If your joint is long, with a dozen or more pins, you must be wary of cumulative error. A discrepancy of 1⁄128" doesn’t have a significant impact when the joint has six pins. But double or triple that number and you may have a joint that won’t close. So the bigger the joint, the more exacting your setup must be.

Cutting the Joints There’s no reason to cut the parts one at a time. It’s tedious work, so you’ll appreciate anything you can do to expedite it. As I already mentioned, if your joint layout begins with a pin and ends with a slot, you can cut sides and ends simultaneously, four parts in a stack. As with the test cut, you align the parts in the stack, stand them on the jig base, upright against the back. Butt the edges against the key. Cut. Step the stack over the key and cut. Step again and cut again. Repeat and repeat until the last slot is cut. If one piece begins and ends with pins, the mate will begin and end with slots, as shown on page 31. They must be cut in sequence. You can, of course, pair up parts of a box, but you can’t cut all four parts at once. Start with the piece that begins and ends with pins. Cut the slots in it. After the last slot has been cut, step that slot over the key. Stand the mating piece beside it, edge to edge, as shown below. Cut. Remove the first piece and slide its mate to the right, the slot over the key. Cut again. Step and cut until all the slots are completed.

If the joint layout begins with a pin and ends with a slot, then all four parts are identical, and all can be cut at the same time.

If the layout on a board begins and ends with a pin, the mating piece must begin and end with a slot. To align the work for the beginning slot, butt the piece against its mate.

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C H A P T ER • 31

Cope & Stick Joints

Photo by Al Parrish

BY GLEN D. HUEY

The moulding profile cut in reverse forms an integral part of the cope-and-stick joint.

The so-called cope-and-stick joint – a.k.a. the rail-and-stile joint, the railand-pattern joint, etc. – is an efficiency expert’s dream system. The joint is virtually synonymous with raised-panel doors. However, that’s a little parochial; you can use it for constructions other than doors, and the panels don’t have to be raised. But its utility in doormaking is more than enough to merit a place in your power-tool joinery repertoire. Typically, two separate bits are used. One is the sticking (or stile or pattern) bit, and the other is the cope (or rail) bit. In one pass, the so-called sticking cutter forms the panel groove and the decorative edge profile. With this cutter

you machine one long edge of the stiles, and the top and bottom rails, and both edges of mullions and intermediate rails. (To my understanding the term “sticking” stems from the profile being formed directly on the frame member – it’s “stuck” there – as opposed to it being a separate strip that’s attached.) The cope cutter forms, all in one cut, a stub tenon (or tongue) that mates with the panel groove and the cope of the sticking profile. Copes are cut across the ends of all rails and mullions. Perhaps it’s a bit of stretch to say this, but a coped joint won’t peek open seasonally the way a miter will. Finish carpenters cope architectural trim at inside corners rath-

er than mitering it for just this reason. The joint thus is cut by milling every frame piece with one bit and selected pieces with the second. I’ve never timed it, but I’d bet that with a little experience, you can set up and cut the joinery for a door in about 10 to 15 minutes. To fully grasp what I mean about efficiency, compare that two-step process against this routine of the traditional door maker: • Lay out each joint. • Excavate the mortises with chisels and a mallet, with a hollow-chisel mortiser, or maybe with a router and jig. • Next, cut the tenons and then fit them to the mortises. • Cut the decorative profile. • Cut the panel groove. • Trim the profile at the joints, an operation usually called mitering the sticking, so the joints close and the profile on the rail meets the profile on the stile in a crisp miter. I’ve recently done this. It’s a lot of setups. It required a hollow-chisel mortiser, three router-table setups and two table saw setups. And to get an acceptable assembly, I actually had to use one of those old-time cordless tools – a chisel. With cope and stick, it’s two router-table setups and you’re done. The trade-off (there’s always a tradeoff) is strength. The joint is easy to make, but it isn’t as strong as a mortiseand-tenon joint. Is it strong enough for the average frame-and-panel application? Personally, I think the joint is fine for doors on cabinets and cupboards, and for casework C O PE & ST I C K J O I N TS

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Step photos by the author

Bits are available as pairs of matched cutters or single bits. Single bits are either height adjustable or stacking with a reversible cutter.

components. Provided it is machined accurately and glued well, it’s plenty strong. If the strength of a mortise and tenon is deemed essential – for heavier assemblies such as architectural doors, for example – there are good ways to reinforce the cope-and-stick joint, such as with dowels and loose tenons. To make a frame using this joinery, you need the proper bits and a midpower, table-mounted router. With a few exceptions, the cope-and-stick bits can be run full-tilt in a 11⁄ 2-horsepower router.

Preparing the Stock By industry convention, cope-and-stick bits are designed for 3⁄4"-thick stock. Because this stock thickness is standard in most areas of the United States and Canada, you shouldn’t have problems if you buy dressed stock. You do have some leeway. You can finesse the bit height setting to reduce the profile depth and increase the width of the panel-groove shoulder, or to increase the profile and reduce the

Set the height of the cope cutter by measuring the position of the tongue.

1 48

shoulder. The problem when you creep below 11⁄16" in thickness is in fitting the sticking profile on the edge and still having enough stock to support the panel groove. As the thickness creeps above 7⁄ 8", the problem is the capacity of the cope cutter. You may find it leaves a wafer of waste attached along the stubtenon shoulder. For doors especially, the stock must be flat, straight and true. You can get away with using slightly bowed stock for a frame-and-panel unit so long as it isn’t a door. If the wood in a frame-and-panel unit is bowed (not crooked, not twisted, just bowed), the unit will be bowed. If the unit is a structural part of the case, it will be anchored to other elements that may pull it into line and hold it there. But if it is a door, it won’t hang flat, and that problem you won’t be able to conceal. Dress the chosen stock to whatever thickness you’ve settled on. You also need several pieces for testing the setups, bearing in mind that these particular pieces can be a secondary wood. The important thing, to me, is to plane all the stock to a consistent thickness. I achieve consistency by planing all of it at the same time. Now rip the stock to width, then crosscut the parts to length. When you cut the rails, you have to account for the sticking width. Usually, but not always, the width is 3⁄8". So if, for example, you’re making an 18"-wide door and using 13⁄4"-wide stiles, the distance between the stiles is 141⁄2". But to account for the sticking, you need to add 3⁄ 4" to the length of the rails (3⁄ 8" for each stile, or twice the width of the profile).

Cutting the Joinery If you have just purchased a bit or set of bits to do cope-and-stick joinery, I think you should spend a little time getting familiar with it. Take as much time as you need to make both cope and stick cuts. Here’s your goal: a setup block with an edge sticked and an end coped. With that in hand, you can quickly set up the bits any time you need to. The usual routine is to cope the rail ends first, then stick all the stiles and rails. So that’s the routine we’ll follow here. Before doing any setup or cuts, reflect on the fact that the cope cut is cross grain. That means you need to back up the work to prevent splinters from being torn from the back edge by the cutter. Depending on the size and number of rails, I’ll gang them up and feed the lot of them past the cutter, pushing them along the fence with a square scrap. The pusher acts as a backup, preventing any splintering. Some woodworkers prefer to use a more formal guide, such as a coping sled. There’s no shame in that at all. However a sled does impact the bit height setting so you have to accommodate the sled base’s thickness. The first setup task, of course, is the bit. Secure the cope cutter in the router’s collet. Then establish a height setting. Knowing the industry standards, you won’t be wrong to measure 7⁄16" to 5⁄8" from the tabletop (or coping sled base) to the corner of the tenon-cutter. You’ll get an 1⁄8"- to 3⁄16"-wide shoulder on the stub tenon.

Use a block of scrap to push the end of the rail into the cutter for the cope. It will prevent tear-out and give you better control.

Use one of the coped pieces to set the height for the sticking cutter.

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Make the sticking cuts by running the long edges along the fence. Featherboards will keep the stock flat on the surface of the router table.

If you already have a setup block – one that came with the bits or one you made – tuck it into the bit and adjust the bit up and down. If you are using a coping sled, you must, of course, set the block on the sled when gauging the bit elevation. Set the fence next, positioning it with its face tangent to the pilot bearing. It helps to use a zero-clearance facing. The zero-clearance fit is most important on the infeed side of the cutter. If your fence is split, you can feed the infeed half of a sacrificial fence into the spinning bit, right up against the pilot bearing. With the solid fences on my router tables, I use an expendable strip of thin plywood or hardboard to make a zero-clearance opening as shown in the photo above. Of course you need to make a test cut. If you have a setup block, fit your test cut to its sticked edge. If not, look at the cut and assure yourself it’s not obviously misaligned. The cope cuts should be completed in one pass. Repeating a pass can enlarge the cut and create a loose fit. In theory,

A zero clearance opening in the fence will help prevent chipping as the cuts are made.

a second pass can enlarge the cut only if there’s some movement in your setup. In practice, there probably is a “skoshe” of movement possible, no matter how firmly you grip the work. Pay attention when you turn the rails to cope the second end. You want to turn them, not flip them over. Mark the face that’s supposed to be up as you make the cope cut. Before you cut, look for the mark. Rout the sticking second. Chuck the sticking bit in the router collet, and adjust its height. It’s great if you can do this without moving the fence, but that’s not always the case. If you can get away without resetting the fence, you’ll save some time and effort. If you have a setup block, use it, of course. Otherwise, set the bit against a coped workpiece. Make a test cut, and fit it to one of the coped rails. You want the surfaces flush, and running your fingers across the seam will tell you if you’ve achieved that. If some adjustment is necessary, make it and run a new test piece across the bit. Keep adjusting and testing until you have the fit you want dialed in. Set featherboards, if you favor their use, positioning them just fore and aft of the bit, where you need the pressure.

When everything is set up properly, after you’ve adjusted and micro-adjusted the bit height, created zero-clearance support around the bit, positioned the featherboards, and done a test cut that resulted in a pleasing fit, rout on. Stick the stiles and the rails. You may find that it won’t take as long to do the work, as it did to set up for it. Taking your time with the setup will guarantee you smooth sailing when you put the parts together.

Assembly Assembling a cope-and-stick frame is pretty straightforward. Work on a flat, true surface. Apply glue judiciously to the ends of the rails. Tighten the clamps gently, alternating back and forth, and keeping the rails flat on the clamp bars. Very little pressure is required, and overtightening the clamps will likely distort the joints and thus the assembly. Make sure the assembly is square and flat by comparing the diagonal measurements and by checking with winding sticks.

The pieces should come together flush on their faces (left), not offset (right).

Cope-and-stick joinery is an efficient method for assembling doors and other panels.

C O PE & ST I C K J O I N TS

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CHAPTER • 32

Dado Joints B Y B I L L H Y LT O N

In casework of any size, using natural or man-made materials (or both), the dado is prime-choice joinery. It follows that hoary adage of woodworking: “Use the simplest joint that will work.” It certainly works. The dado joint is traditional, with a centuries-long history of use in cabinetmaking. It definitely is simple. All dado joint variations derive from the cut itself. A dado is a flat-bottomed channel cut across the grain of the wood. (When it runs with the grain, the channel is called a groove.) You cut a dado or groove into one board, and the mating board fits into it. One well-placed, properly sized cut with the proper tool makes the joint. And with today’s power tools, it’s a cut that is almost trivial to make – if you know how. The dado does not have to be deep to create a strong joint. One-eighth inch is deep enough in solid wood, 1⁄ 4" in plywood, medium-density fiberboard (MDF) or particleboard. The shallow channel helps align the parts during assembly, and the ledge it creates is enough to support the weight of a shelf and everything loaded on it. The dado also prevents the shelf from cupping. The one stress it doesn’t resist effectively is tension. In other words, it doesn’t prevent the shelf from pulling out of the side. Only glue or fasteners can do that. Because all of the gluing surfaces involve end grain, the glue strength is limited.

Different Kinds of Dados When the dado extends from edge to edge, it’s called a through dado. It’s easy 1 50

Depth Width

THROUGH DADO

BLIND DADO

to cut. The most common objection to it is that it shows. However, you can conceal the joint using a face frame or trim. A dado or groove doesn’t have to be through, of course. It can begin at one edge and end before it reaches the other (stopped), or it can begin and end shy of either edge (blind). This version is a little trickier to cut. To make a stopped or blind dado, the corners of the mating board must be notched, creating a projection that fits in

STOPPED DADO

the dado. Sizing the notches so you have a little play from end-to-end makes it easier to align the edges of the parts. But it does sacrifice a bit of the strength that the narrow shoulder imparts.

Cutting Dados There are some other joints that begin with dados, but before I even mention them, let’s deal with the basic joinery cut. There are scads of ways to cut a dado successfully.

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Table-saw Dados Let’s look at the table saw first. It’s powerful and equipped with accessories – a rip fence and a miter gauge – useful in positioning cuts. Like a lot of other woodworkers, I use a shop-made cutoff box (instead of the miter gauge) for crosscutting – it also works for dados. To use the saw effectively for dadoing, you need a dado cutter, either a stack set or a wobbler. You can waste a narrow dado pretty quickly with whatever blade is on the saw. If you’ve got a manageable workpiece and just one or two dados to cut, you make five to seven kerfs to form each one. But to cut a cabinet’s worth of dados, use a dado cutter. If you’re making cabinetry assembled

with through-dado joints, you can knock out a lot of consistently sized and placed cuts in short order. What isn’t necessarily quick and easy is achieving the precise width of cut you want. Stack sets, which give the cleanest cut, consist of separate blades and chippers. You have to select the combination needed to produce the approximate width of cut desired. To tune the cut to a precise width, you insert shims between the blades. It’s got more trial-and-error in the setup than I like. Some woodworkers (those with too much time on their hands, I think) make a chart or a cut sample with notes on the combinations of blades, chippers and specific shims needed to produce common-width dados. If you have the patience for this endeavor, my hat is off to you. Go for it. But the woodworkers most likely to use the table saw for dadoing are those who are looking at a lot of cuts and not a lot of time to make them. Often, these folks adopt work-arounds to avoid protracted setups. They’ll shoot for an undersized dado, and then plane or sand the part to be housed in it to fit. Or they’ll use the dado-and-rabbet joint: The mating part is rabbeted to form a

Photos by the author

Keep a couple of criteria in mind as you tackle the dado cut. To end up with a strong joint, you need to make a cut of the correct width. The bottom needs to be smooth and flat, the sides perpendicular. If the cut is too wide, glue isn’t going to compensate; the joint will be weak. Get the fit right. The two most obvious power tools for cutting dados are the table saw and the router. But there are other options. You can do dados with a radial arm saw. If you are comfortable with this machine, you probably can recite the advantages. Fitted with a dado head, the radial arm saw hogs through dados quickly. The workpiece is face up, so you can see what you’re doing. Layout marks are visible, and you can line up each cut quickly. When a stopped dado is needed, you can cut to a mark. The work isn’t moved during the cut, so the piece is less likely to twist or shift out of position. This is especially helpful on angled cuts, whether a miter or a bevel (or both). I have cut dados on narrow workpieces using a sliding compound miter saw. Most such saws have a cut-depth adjuster; you set the cut depth (with some trial and error), then “waste” each dado with kerf after kerf. It’s one of those operations you do once, just to try it. And once was enough for me. I prefer to stick with my table saw and my router for cutting dados.

A dado stack set consists of separate blades, chippers and washer-like shims. You fit the elements onto the saw’s arbor, one by one.

tongue that fits whatever dado has been cut. How do you locate and guide the cut? The rip fence is seductive, because it allows you to locate a cut consistently on both sides of a cabinet or bookcase. It eliminates the need for layout. But it isn’t a crosscutting guide, and dados are crosscuts. Of the two crosscutting guides, I prefer the cutoff box. It’s built specifically for right-angle cuts and rides in both miter-gauge slots (instead of just one).

An accurate, shop-made cutoff box is the best guide accessory to use for dadoing on the table saw. Set the cutoff box on the sled base, tight against the fence. The work won’t shimmy or shift out of position as you slide the box across the dado cutter.

DA D O J O I N T S

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The typical router table setup works for dadoing parts like drawer sides. A push block – just a square scrap – stabilizes the work and backs up the cut, preventing tearout as the bit emerges from the cut.

In addition, it effectively immobilizes the workpiece, because the box is what moves, carrying the stationary workpiece with it. The work doesn’t squirm or twist as you push it into the cutter. Fit the box with a stop so you can accurately and consistently locate a cut on multiples without individual layouts. Stopped cuts can be problematic, and blind cuts can be downright hazardous. Because the work conceals the cutter, and because the cutoff box conceals most of the saw table, it’s tricky to determine where to stop the cut. One good option is to clamp a stick to the outfeed table that stops your cutoff box at just the right spot. A blind cut would require you to drop the work onto the spinning dado cutter. Not a routine that I’d recommend. Any stopped cut done with a dado head will ramp from the bottom of the cut to the surface. You can leave it and simply enlarge the notch in the mating piece, but in so doing, you sacrifice the strength in the joint that comes from a tightly fitted shoulder. Better to chisel out the ramp.

Routing Dados The router’s often touted as the most versatile tool in the shop, and it certainly is useful for dadoing. The cutters offer convenient sizing: Want a 1⁄ 2"-wide dado? Use a 1⁄ 2" bit. Want a dado for 3⁄ 4" plywood, which is typically under thickness? Use a 23⁄ 32" bit. Changing bits is 1 52

Dado large workpieces on a router table with a cutoff-boxlike sled. A stop clamped to the sled’s fence locates the cut and immobilizes the work. Slides on the underside reference the edges of the tabletop to guide the sled.

2" 27/8"

Stop bar shift position right or left to locate cut, clamp to front fence Back fence 11/2" x 11/2" x 30" hardwood

Slot for router bit position varies from table to table

Front fence 1 1/2" x 3" x 30" hardwood 27"

Base 1/4" plywood or MDF

Slide

30"

Slide 7/8" x 1 1/4" x 30" hardwood

Width of tabletop

DADO JIG

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quick and easy. The tool also offers options on approach. If you have your router hung in a table, dadoing with it is much like table saw dadoing. But the router gives you the option of moving the tool on a stationary workpiece, and in many situations, this turns out to be the better approach.

On the Router Table For a long time, my mantra has been that you can rout grooves on a router table more easily than you can dados. Consider the typical router-table setup. It’s small in comparison to the typical table-saw setup, with its expansive infeed and outfeed tables. So I’d say, limit yourself to dadoing small parts only, things such as drawer sides. Guided by the fence alone, you can easily rout grooves. The grain runs along a workpiece’s long dimension, so a groove is easy to locate and cut guided by the fence. But try guiding the workpiece’s short dimension edge along the fence. Or locating a dado 16" from that edge. Or 24" or 30". Maneuvering a 6'-long bookcase side or a 24" by 36" base cabinet side on a router table top is a Keystone Kops routine. But a drawer side – where the piece is small and the dado (for the drawer back) is close to the end – can be routed pretty easily. You use a square-ended push block to keep the work square to the fence as you feed it and to back up the cut. Large case parts are best done on the table saw or with a hand-held router. Recently, however, I made a cutoff box-like accessory for my big router table. I don’t like miter gauges (or the slots they require) on a router table, so the dadoing box I made is guided by the tabletop’s edges (see the drawing below). I’ve dadoed some pretty large workpieces with it. The setup was simple, the

A crossbar attached at right angles to a plywood straightedge makes it an easy-to-align T-square guide for dadoing with a router. Clamp it securely to the work and the benchtop at each end.

The gap between the fence bases on my dadoing jig represents the cut width. Pinch scraps of the work material between them to set the jig.

Position the jig by setting the fence base edge directly on your layout line. The crossbars ensure it will be perpendicular to the reference edge.

Cutting a dado is foolproof. The router is trapped between fences and can’t veer off course, regardless of your feed direction. Reference the left fence as you push the router away, reference the right one as you pull it back, completing the cut.

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operation downright easy and the results were clean and precise. This accessory is changing my attitude, I must say. It offers all the advantages of the table saw-cutoff box setup, but eliminates the trial-and-error with the stack set. You do need to use a stop to position the work, because the stop also prevents the bit from moving the work. The bit in a table-mounted router is spinning counterclockwise, and it will pull work to the right. You put the stop on the right to counteract that dynamic. (It’s the equivalent of positioning the fence on the right.)

With a Hand-held Router I’m not ready to entirely abandon the router as a hand-held tool, however. It remains a prime choice for dadoing large workpieces, such as sides for a tall bookcase or base cabinet. It seems easier and safer to move a relatively small tool on top of a cumbersome workpiece than the other way around. The big question is how you will guide the router for the cut. A shopmade T-square fits the bill, as does a manufactured straight-edge clamp such as the Tru-Grip. An accurate T-square doesn’t need to be “squared” on the work, as a Tru-Grip-type clamp does, but positioning it accurately can be a trick. A setup gauge is helpful here. Cut a scrap to match the distance between the edge of the router baseplate and the near cutting edge of the bit. Align one edge of the gauge on the shoulder of the desired cut and locate the T-square (or other guide) against the opposite edge. Bingo. The guide is set. Though more elaborate to construct, my favorite dadoing jig is easy to position on simple layout marks, and it adjusts easily to cut the exact width of dado you need. You size the jig to suit your needs. The jig has two 1⁄ 2" plywood fences, each laminated to a 1⁄ 4" plywood or MDF base strip. Both are matched to a particular router and bit by running that router along the fence, and trimming the thin base with the straight bit. One 1 54

Cabinet sides clamped edge-to-edge

Dadoing cabinet sides? Clamp them edge-to-edge and rout both at the same time for cuts that line up perfectly.

For stopped or blind dados, clamp stop blocks to the jig (rather than the work). Move the jig, and the stops move with it. Using the plunge base eases beginning and ending these cuts.

fence is then screwed to two hardwood crossbars. The bars must be perpendicular to the fence, of course. The second fence is mounted so it can be adjusted toward or away from the fixed fence as shown in the photos. Obviously, you cannot produce a dado narrower than the cutting diameter of the router bit, but you can do a wider one easily. Because the router is trapped between two fences, the feed direction is less of an issue and mis-cuts are unlikely.

The bases make it easy to adjust the cut width and to position the jig on simple layout marks. To do the former, use a scrap or two of the stock to be housed in the cut as gauges. Set them against the fixed-fence base, slide the adjustable fence into position and lock it down. To do the latter, align the fixed-fence directly on one of the marks, with a crossbar tight against the work’s edge. Secure the jig to the work with two clamps.

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CHAPTER • 33

Living on the Edge The edge joint may be the most fundamental joint in woodworking. Any time you need a solid-wood panel more than 6" wide, you likely create it by gluing boards edge-to-edge. Casework, tabletops, door panels, drawer fronts, shelves, headboards and footboards all require boards or panels of a width that outstrips available stock and the capacity of home-shop machinery. The most widely used type of edge joint couldn’t be simpler – just two boards with straight, square edges and some glue. A properly fitted glue joint is stronger than the wood, so if you assemble this joint correctly the boards will split before the joint ever will. So why are there so many variations – splines, biscuits, interlocking profiles – that add complexity and additional parts? Well, sometimes woodworkers can’t accept that a simple joint is better than one with a bit more mechanics to it. Often, splines and biscuits can be assembly aids. Getting the stock flat, square and true is the biggest task to making a good edge joint. Master that and you’ll have no trouble constructing strong, simple edge joints. But to do a proper job dressing stock, you need three machines: a jointer, a thickness planer and a table saw. Together, they can represent a significant cash outlay. The upshot is that you may be able to work around the lack of a jointer, a planer or both. You may not have the flattest stock to work with, and a spline or some biscuits can help you line up a

Photos by the author

B Y B I L L H Y LT O N

Glue up a panel with clamps across the top and bottom to keep the assembly flat. Make sure you use plenty of clamps on your workpiece to spread enough pressure across the entire joint.

slightly bowed board with its mates during glue-up.

Butted Edge Joint Whether it’s for a dining table’s top or a small door’s panel, jointing the boards and gluing up a panel follow the same routine. First lay out the dressed stock and find the arrangement that pleases you. Mark the stock so you can remember the arrangement, then gather up the boards and joint the edges, making them straight, smooth, true and, of course, square to the faces. Then put together your panel on a flat surface. If your assembly table is bowed or twisted, you’ll have difficulty creating a flat glue-up. Do a dry-fit first. Set out the clamps, position the boards and cauls, and run

through the clamping. The joints must close with moderate pressure. If you need to really crank to close the joints then you know you need to rejoint the edges first. I use an odd number of clamps and begin tightening the center one before I work out to the ends, alternating from one side to the other. To keep the panel flat, I set alternating clamps across the top surface of the panel. Spread your glue, set the boards on the bottom-side clamps and move the top-side clamps into place. As you tighten each clamp, make sure the faces are flush by rubbing your thumb over the seam. If you’re uncomfortable trying to monitor two or three seams at once, which you must do if you’re gluing up LIVING ON THE EDGE

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4" See detail below for bit opening 36" Rout the first half of an edge joint by guiding the router along a fence clamped atop the workpiece. The feed direction here is rightto-left (moving away from the camera).

Glue plastic laminate to outfeed side only Straight bit

Bit clearance hole Glue two strips of 3/4" MDF

BIT OPENING DETAIL Align face of plastic laminate with cutting diameter of bit

BUTTED EDGE JOINT

SPLINED EDGE JOINT

BISCUITED EDGE JOINT

DOWELED EDGE JOINT

1 56

The bit cutout is large enough to accommodate my glue joint bit, so I can use it with that bit or a straight bit. Just secure it to the table with clamps. Lock down one end of the fence, leaving the other end free to allow for slight movement. Hold a straightedge against the outfeed side of the fence, extending it across the bit. Adjust the fence so the bit’s cutting edges are even with the straightedge. Then make a test cut by jointing the first 5" of a 12" scrap. If the cut stalls when the scrap hits the edge of the outfeed section, increase the bite. If the jointed stock isn’t supported – if you can slip a piece of paper or a feeler gauge between the stock and the outfeed facing – you need to reduce the bite. The ideal bit in these cases is a fairly heavy but well-balanced 1⁄ 2"-shank straight bit.

Using a Hand-held Router In this case, clamp a straightedge atop the first workpiece and, guiding the router base against the fence, trim about 1⁄ 16" from the workpiece. Then secure the second workpiece directly opposite the first. Adjust the gap between it about 1⁄ 16" less than the diameter of the bit. By guiding the router along the same fence – you haven’t moved it – trim the second workpiece and produce

Position the mating board opposite the first, with a gap just smaller than the diameter of the bit between the two workpieces. The feed direction when routing the second edge is left-to-right.

three or four boards, you will need to do more than one glue-up. First do two glue-ups of two boards each, wait about half an hour for the glue to set, then do a third glue-up joining them together.

Using a Router Table If you don’t have a jointer, you can substitute a router: Either set up a router table for jointing or you can produce an excellent butted edge joint using a handheld router. But keep in mind that router setups are not ideal for handling rough lumber. On the table, you need a fence with a slight offset between the infeed and outfeed halves – just like the tables on a jointer – so that the work will be supported before and after the bit trims away stock. If you use a fence with split faces, you can shim the outfeed half with cards or plastic laminate. This would apply to most commercial fences. I’ve made a simple fence that I can use on any of my router tables. It’s just two strips of 3⁄ 4" medium-density fiberboard glued together with a piece of laminate attached to the outfeed side.

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an edge on it that’s a negative image of the edge milled on the first workpiece. The two boards should fit together perfectly. Because you’re cutting positive and negative contours of the fence, it doesn’t need to be perfectly straight. In fact, you can produce slightly curved edge joints this way. To do this, you will need to elevate both boards slightly so the router bit doesn’t groove your workbench. Both boards should be in the same plane so the router can remain square to the edges throughout both cuts. Make sure you work out a placement that allows you to secure both workpieces, such as orienting them across the benchtop. Feed direction is important, and the direction that’s correct is different for each board. You’ll be cutting one board on the first pass, the other on the second. Don’t cut both at the same time. If you stand where the fence is between you and your router, the feed on the first board is right-to-left, while it is left-toright on the second.

Biscuited Edge Joint Despite the strength of the glued edge joint, many woodworkers opt to embellish it with biscuits, splines or dowels. Machining the boards for these elements can be extra work, but when the assembly is complex or the wood is mildly bowed, biscuits and splines can help create a flat glue-up. Dowels, on the other hand, are not a good option. It’s difficult to drill matching holes in the mating boards. Unlike biscuits, dowels offer no margin for error. On top of that, dowels introduce a cross-grain element to a long-grain joint – if the wood shrinks, the dowels can push the joint apart. Biscuits are an excellent alternative, and pretty easy to accomplish. Cut a series of slots in the mating edges with a biscuit joiner. As you glue up the joint, insert a football-shaped biscuit into each pair of slots. The biscuits register the surfaces, but allow a degree of endto-end adjustment. Accurate alignment during glue-up is virtually foolproof.

For the routed glue joint, mark the center of the work and align the sweet spot on the glue-joint bit with your mark. It probably won’t be perfect, but it’ll get the setup process started.

Biscuit slot layout is simple. Line up the boards as you want to assemble them and then mark a line across each joint every 6" to 8" where your slots will go.

Routed Glue Joint This industrial joint was developed for high-volume production glue-ups. In that setting, the stock is propelled across a shaper with a power feeder and the cutter simultaneously joints and profiles the edge in a single pass. One edge is milled with the face up, the other edge with the face down. Long ago, the cutter was scaled down for use in a router table. Because it’s typically less than 2" in diameter, it can be run at full tilt (22,000 rpm). But because it’s a substantial bit and removes a major amount of stock, lots of horsepower is a prerequisite. The concept, of course, is that you have a single setup of bit height and fence position. One board is routed face up, the other face down. If the setup is correct, the two boards will come together with their faces flush. Because of the interlock, the fit is a cinch; the boards can’t shift up or down. The gluing surface is expanded, too. But the setup is easier explained than dialed in. (Once you’ve done it, it’s easier to repeat.) The center of the profile must fall on the center line of the stock or the faces won’t assemble flush. Also, milling the stock’s full edge with the bit requires the infeed and outfeed halves of the fence to be offset from one another (just as you set the tables on your jointer).

Align the outfeed side of the fence even with the cutting edges of the bit’s smallest diameter. Use a straightedge and turn the bit by hand to find the correct alignment.

Check the fit of the joint. You want the faces to be flush. If you are milling both edges of a workpiece, alternate the profile from edge to edge, as shown.

Setup Sequence • Eyeball a bit-height setting. I do this by marking the stock center line on a setup sample and setting it beside the bit. Then I raise and lower the bit to visually align its center point as best I can with the mark. I use this setting to set the fence, then come back to the bit and fine-tune its elevation. • Next, shim the outfeed half of the fence. I usually use two or three thicknesses of index-card stock. The shims go between the fence and its facings. If you use the jointing fence, shimming isn’t necessary, as the infeed-outfeed offset is established. • Align the outfeed half of the fence with the small-diameter cutting edge. Lock down one end of the fence and adjust it by swinging the free end back and forth. Align the fence visually, then check it with a straightedge held against the outfeed side and across the cutting edge. Clamp the free end. Confirm the setting with a partial test cut. Begin the cut and feed several inches beyond the bit. Switch off the router and check if the edge contacts the outfeed side of the fence. • Finally make a test cut on a short piece of the working stock. Cut the piece in half and fit the parts together to assess the fit. If the faces are not flush, you need to change the bit height by half the offset. LIVING ON THE EDGE

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CHAPTER • 34

Face Frame Face-Off BY JIM STUARD & STEVE SHANESY

Today, many woodworkers move freely between building frameless cabinets and those with face frames, viewing one style or the other as a design consideration only. But to do so and disregard the engineering advantages and disadvantages of each method is a significant oversight. The assembled components of any cabinet that lacks a face frame or back have an enormous propensity to shift from side to side with only a slight bit of force. Add a face frame to the cabinet and the structure has integrity. Take away the face frame but add a sturdy 1⁄ 3 2" or ⁄ 4" back, and the frameless case is structurally sound. So now we know that face frames add structural integrity and suggest a certain style (albeit still generic) cabinet. But there’s more. The face frame also provides openings with square corners that make fitting doors and drawers a predictable task.There’s nothing more aggravating than tediously fitting a door in an opening that’s out of square. Lastly, face frames cover the front edges of the cabinet’s sides and partitions, which are often made from plywood or particleboard.

Face-Frame Components Face-frame parts have specific names and orientations within the frame. Stiles always run vertically; rails are always horizontal. Stiles always run through, and rails always run between stiles. Intermediate stiles (sometimes called muntins) and intermediate rails are 1 58

always located within the main frame surrounding the cabinet. An intermediate stile will run between a top and bottom rail, and intermediate rails will always run between stiles. These arrangements of parts help provide a rigid structure that gives the case parts strength. To derive this structural integrity, face-frame components need to be of a certain size. You’ll find that most face-frame base cabinets (the kind you would find in kitchens) have 2"-wide stiles, 31⁄ 4"-wide top rails, 5⁄ 8"wide bottom rails and 11⁄ 2"-wide intermediate rails. Smaller cabinets can have somewhat narrower parts, but functionality suffers, with stiles less than 11⁄ 2" and rails less than 11⁄ 4". Face frames are attached to cases in several ways, and the method used has often been one of the important factors in determining the quality grade of the cabinet work. Face frames with mitered end stiles glued to mitered cabinet sides

are a premium grade. Next, frames that overlay the sides and are only glued and clamped would be the next best grade. Lower grades would include frames glued and nailed, on and frames nailed on only. The following pages show you four common ways to join rails and stiles and compare the ease and expense of each method. All four methods are used in commercial shops and are appropriate for face-frame construction at home.

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FAC E F R A M E FAC E- O F F

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Mortise and Tenon A TRADITIONAL AND TOUGH JOINT THAT’S TIME-CONSUMING

First mark a centerline down the edge of the part getting mortised. Place the part into the mortiser and line up the point of the bit in the mortising chisel on the line. Always do a practice cut on scrap and use that to check the tenons you’ll make on the saw.

LAY OUT A PRACTICE MORTISE.

a dado head in a table saw is easy. Set a 3⁄ 4"-wide dado stack to the height of the shoulder on the mortise. Set the saw fence to the length of the tenon (in this case, 1"). Always do a test cut, using the test mortise from the mortise setup. Cut the shoulder first. This keeps tear-out on the shoulder to a minimum. Cut the rest of the tenon and check the fit with the mortise. Next, set the dado stack to 1⁄ 2" high for cutting the top and bottom shoulders. Cut the shoulder first, then finish the cut. Check the fit. It should be snug without being tight.

CUTTING A PRACTICE MORTISE. Be sure your work is clamped down well. Mortising bits are prone to stick and require serious pressure to keep the piece in place. After making the first hole, the drilling gets easier. Use a hole-skipping technique. That’s drilling one hole, then skipping over one chisel width and making another.

CUTTING TENON CHEEKS. Using

1 60

LAY OUT THE MORTISE. Take

the tenon you’ve cut and lay it right on the stile that requires the mortise. Use the tenon like a ruler to mark the stopping and starting points of the mortise. Now cut your mortise in the same way you cut the practice mortise.

Pros + More wood-to-wood contact makes it a stronger joint: If you actually measure the wood-to-wood contact that takes place in a mortise-and-tenon joint, there is a greater area of contact here than any other joinery style. + Can be made entirely with hand tools: If necessary, this joint can be made with only a layout tool, a saw and a couple chisels. That makes it one of the cheapest joints to make. However, it is also the most labor- and skill-intensive method. + Appropriate for reproduction furniture: Mortise-and-tenon joinery shows up in the coffins of Egyptian mummies that are thousands of years old. It was used extensively and almost exclusively on furniture made from the Middle Ages up to around the 1850s. + Easy glue-up: There’s no chance of your parts bowing under simple clamping pressure. The tenon provides a solid backbone to the joint. + No material size constraints: You can make any size joint that you want. The tenons on some wider materials will have to be split up to keep wood movement down.

Cons - Highest skill level required: Cutting one of these joints by hand requires a great deal of time and talent before it can be done with any kind of regular accuracy. - Can be the most expensive method: The machine method shown is very accurate and easy to learn. It also can be the most expensive. Add up the cost of a table saw, mortiser and tooling for both and you can easily go over $1,000. - The slowest method: Either by hand or machine, the layout and setup time required to do mortise-and-tenon joinery is the longest of all the techniques. - Unnecessary amount of strength for a face-frame cabinet: Mortise-and-tenon joinery was necessary back in the days of hide glue and no screws, dowels or biscuits. These days, modern fasteners and glues make this an unnecessary joinery style for face frames. Do it if you like, but there’s a time consideration to be paid for all that historical accuracy.

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Pocket Screws SAY FAREWELL TO YOUR CLAMPS WITH THIS HIGH-TECH METHOD

LAY OUT A JOINT. The instructions for the Kreg jig are simple and few. There just isn’t that much to learn. All you really have to do is line up the center on the back side of the part being drilled between the best spacing of the three holes on the jig. To do this, mark a centerline down the middle of the part to be machined.

DRILLING POCKETS IN THE RAIL. Place the rail in the jig and with the bit set for the proper frame thickness, drill the angled hole. The bit makes a stepped clearance hole for the special screws used to attach the frame together. The screws drill their own pilot holes into the stile.

CLAMPING AND SCREWING. There

are different types of screws. Screws with coarse threads are for softwoods such as pine. Fine thread screws are used for hardwoods. A third type of screw works for both. All three types drill their own pilot holes thanks to a milled notch in the shank that works like a drill bit.

Supplies Woodcraft 800-225-1153 or www.woodcraft.com

Pros + Few width restrictions: The only width restriction you’ll possibly face is a rail that’s too small for one hole (about 3⁄ 4"). If you’re using rails the same thickness as the cabinet sides, you might as well nail the parts on and call it a frameless cabinet. + No clamping required: Outside of using the supplied Vise-grip to align the joint for assembly, if the parts are cut square and the correct screws are used, there is no need for clamps. + Fastest joint from layout to finished product: I timed every operation using this jig; without a doubt, it makes a ready-to-apply frame in the shortest time. I came up with less than a minute for each joint. The learning curve is almost non-existent for this method. It’s very easy to pick up. + Self-contained system — except for the drill: The Kreg K4 Master System came with everything you need to get started, except for a corded drill. The kit’s price, about $140, put it in the mid-range for equipment costs when compared to other joinery methods.

Cons - Cost per joint is high: If you don’t want to plug your screw holes, each joint is going to cost you about 8 cents (less if you buy your screws in bulk). If you want to plug your holes, the cost goes up to about 36 cents a joint. Biscuits and dowels cost between 2 and 3 cents. If you’re in a big hurry, saving at least 30 minutes of time when clamping up your face frame can be worth it. - Visible joint on the interior of the cabinet: Requires special (and expensive) plugs if you want to conceal the screw holes.

Kreg K4 Master System, item #151277, $139.99

FACE FRAME SCREWS: Troy Sexton recommends QuickScrews from S & G Specialty Fasteners Inc. 800-743-6916 or www.quickscrews. com Sexton recommends S & G’s #7 x 11⁄ 4" Hi-Lo thread all-purpose screws (part #7622). Call S & G for a distributor near you.

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Biscuits LIKE POCKET SCREWS, BISCUITS ARE QUICK, ACCURATE AND EASY

Pros + Fast joint: With the exception of the pocket screw jig, biscuit joinery is the fastest method going. All you do is mark a centerline on a rail and stile. Set the joiner and you’re off to the races. This was the first time I’d used the face-frame blade in the Porter- Cable 557 joiner, and I had some problems with the parts moving around. A clamp did the trick.

+ Most forgiving technique: Pocket screws MARKING THE JOINT. When

marking the joint for the biscuit slot, butt the pieces together and measure over roughly half the width of the rail and mark a line across the joint. A combination square holds everything square for an accurate mark. Mark your parts all face up or face down so your slots will align.

SETTING THE JOINER. Most

biscuit joiners have a scale that shows you where the center of the blade is. Some, such as this one, even have a setting for the center of a 3⁄ 4"-thick part. Set the joiner and make a test cut on some scrap to make sure you aren’t cutting past the width of the end of a rail.

aside, this is the most forgiving technique. The slots are bigger than the biscuits, so you routinely get almost a 1⁄ 4" of slop in the joint for alignment.

+ Learning curve is low: It takes little time to learn how to make one of these joints. While it’s been awhile since I learned how to use a biscuit joiner (over 15 years), I’m always amazed at how easy these tools are to use.

Cons - Biscuits can telegraph through the joint:

MAKE THE CUT. If you use Porter Cable’s face-frame biscuit cutter in the PorterCable 557, be sure to use a clamp to hold the parts in place. Place gentle pressure on the fence to make sure the joiner remains square to the part.

GLUE UP. One of the many uses I’ve found for plastic lids is as small glue pans. I cut up a disposable cardboard-handled paint brush for applying the glue. Use a small brush with somewhat stiff bristles to spread the glue. This gives you more control of the glue during application. Paint glue on half of the biscuit and press it into one slot of the joint. Then paint glue on the exposed part of the biscuit and assemble the joint. Clamp up your work and measure across the corners to check for square.

A biscuit is like a sponge and will wick up moisture in glue. If a biscuit is installed too close to the surface of a joint, it can expand and create a bump in the surface. You see the bump and flush it up. When the biscuit dries, it takes the surface of the joint with it, creating a hollow. Avoid this problem by cutting your slots in the middle of the thickness of the parts.

- Stock dimensions have limitations: There is a limit on the smallest width of rail you can use. With the Porter-Cable’s faceframe biscuits, I could only make a rail about 15⁄8" wide before cutting through the sides of the rail. You can get smaller dimensions using Ryobi’s Mini Biscuit Joiner. Here are the maximum widths of the rails for common biscuit sizes. Biscuit # Width Ryobi R1 1" Ryobi R2 13⁄ 16" Ryobi R3 13⁄ 8" Porter-Cable FF 15⁄ 8" #0 23⁄ 8" #10 21⁄ 2" #20 23⁄ 4"

- Biscuits are high-maintenance fasteners: Store them in a dry environment, such as a resealable jar or airtight bag. Here’s a tip for biscuits that won’t fit in their slots: try microwaving them.

- Watch for bending: If you use too much clamping pressure, it’s possible to bow the parts. Ease off on the pressure and compensate by placing clamps on both the front and back sides of the frame.

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Dowels THIS JOINT REPLACED THE MORTISE AND TENON AND IS STILL A FAVORITE METHOD OF SOME

Pros + No material size restriction: Like the pocket hole jig, you can use almost any width of stock for your rails.

+ Modest equipment costs: All you need is a jig (costing $40 to $70), some dowels and a drill.

+ Good solid joint for face frames: With the extra gluing area (more than a biscuit but less than the mortise and tenon) this is a very strong joint that is just right for face frames. IMPROVING THE JIG. Most

doweling jigs have marks that are obviously meant to be seen only under a microscope or by a test pilot with 20-15 vision. Improve the visibility of your jig by painting a contrasting paint on the increments. This self-centering jig had a black painted finish so I used white paint. Make a “brush” from a pine splinter whittled to suit the job.

MARKING THE JOINT. Use

the same technique for marking dowel joints as you would use for biscuits. You have to be pretty accurate. Mark in about 1⁄ 2" from both sides. On a joint that’s wider than 3", put a third dowel in the center.

3 DRILLING THE STILE. Use ⁄ 8"

dowels in 3⁄ 4"-thick material. Clamp the stile so that enough of the edge protrudes from the clamp to attach the doweling jig. Line up the 3⁄ 8" hole on the layout mark. You want the hole depth to be 1⁄ 16" deeper than the dowel will go. Use a brad point drill with a stop collar. You’ll find that you get better results when you use a corded drill with its higher speed and torque than you will with a cordless drill. DRILLING THE RAIL. Clamp the rail so its end is sticking straight up in the air. This is when it can get dicey. You have to make sure the jig is clamped to the end of the rail and square with the part. If not, you’ll get a hole that’s out of parallel with the holes on the stile. You might have to transfer the layout marks to the other side of the part and turn the jig around to get the jig to stay put.

+ Easier than mortise and tenon to learn: The only critical skills are the ability to lay out the joint correctly and holding the jig square with the parts.

Cons - Tricky to align: If you botch the alignment of the holes even the slightest bit, the joint will be difficult or impossible to assemble. Always double-check the jig’s position on your work.

- You need good equipment: A good jig and stop collars are paramount to getting good results. Dowel-it and Stanley both make good jigs.

- Dowels must stay dry: If they get any moisture on them, they’re subject to the same problems as biscuits in getting them into a hole.

Supplies Woodcraft 800-225-1153 or www.woodcraft.com Dowel-It deluxe jig, item #811565, $59.89

2" GLUING. Dowels

are made with small splines that discourage the joint from “going hydraulic.” What this means is that a dowel without splines (or a spiral cut in the side), can act like a piston when clamped. The dowel effectively plugs the hole, and the resulting back pressure can actually keep a joint from clamping together (or at least make it very difficult to clamp). Put just a small amount of glue in the hole and be sure to apply glue to the dowel as well.

3/8" x 1 1/2" fluted dowel

CL 1/2"

3/4"

1" dowel centers

Stile

3/4"

2"

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CHAPTER • 35

Ultrafast Frame & Panel BY TROY SEXTON

Illustration by Mary Jane Favorite.

Without a doubt, mortise-and-tenon joints make the strongest frame-andpanel doors. But this traditional joint strikes fear into the hearts of beginning woodworkers because it requires either precision with a hand saw and chisel or a deep wallet to buy some serious machinery. After 17 years of building doors, I’ve found a method that is fast enough for a professional cabinetshop but uses tools you’d find in a home workshop. Essentially, you cut your tenons with a dado stack in your table saw. You

1 64

cut your mortises with a hollow chisel mortiser, mortising attachment for your drill press or Forstner bit. And you make your raised panels using a router table, table saw or even a shaper. Now before you start thinking that this sounds really expensive, let’s take a minute to do the math. You probably already have an 8" dado stack. If not buy one for $85. There’s lots of other ways it will be useful in your shop. If you don’t have a hollow chisel mortiser, it would be nice to get one of these, too. A decent benchtop model will cost $250, or you can buy an attachment for your drill press for $75. Mortising equipment will change your woodworking. Suddenly it’s child’s play to make everything as stout as a mule. If you don’t want a hollow chisel mortiser, you can cut these mortises by chain-drilling overlapping holes using a Forstner bit in your drill press. Finally, to make the raised panel you can use a raised-panel bit in your router table or shaper, or you can raise the panel on your table saw using a rip blade. I design my inset doors (as I did for this project) so they’re exactly the same dimension as the door opening. Then I trim them down on my jointer to get a perfect 1⁄ 16" gap all around. Begin building your doors by milling out your stock to the proper thickness. Doors are made up of stiles (the vertical pieces), rails (the horizontal pieces) and the panel. Make your rails and stiles 3⁄ 4" thick and your panel 5⁄ 8" thick. Cut your rails and stiles to size but leave the panel oversized until assembly.

Cutting Tenons I like to cut the tenons first because it is faster. Here’s why: Your mortising bit (or Forstner) makes a slot of a consistent width (unlike when you make a mortise using a chisel and mallet). That means you can depend on every mortise to be exactly as wide as your first one. So if you cut your tenons on the rails first (with the help of a piece of scrap with a mortise in it), you can simply lay the tenon on the stile where it needs to go and use the tenon like a ruler to mark the starting and ending point of the mortise. This procedure saves you a step because you don’t have to get out your combination square to figure out where your shoulders will go on the stiles. For most cabinet doors I like to cut tenons that are 1" long and have 1⁄ 2" shoulders. The rule of thumb is to make your tenons one-half the thickness of your stock. So for 3⁄ 4" stock your tenons should be 3⁄ 8" thick. I cut my tenons on the table saw using a dado stack. Here’s how. First get a piece of scrap. Go to your mortiser or drill press and make a long mortise in that scrap using a 3⁄ 8" bit. You use this piece of scrap to check the thickness of your tenons. Make the mortise in the scrap about 11⁄ 16" deep. Install your dado stack in your saw. The number of chippers isn’t critical. Make the stack 5⁄ 8"- or 3⁄ 4"-wide. Now raise the dado stack so it’s 3⁄ 16" high. Set your table saw’s fence so that the distance from the leftmost tooth to the fence is 1". Get out your miter gauge and

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make sure it’s set perfectly square. Put your rail flat down on the table of the saw. Define each side of the tenon in two or three passes as shown in the photos. Hold the work firmly and keep your fingers away from the blade. Flip the rail over and repeat these cuts on the other side. If you have trouble with tearout, try making the first cut on the tenon with the tenon against the fence. It can help. Now raise the dado stack to 1⁄ 2" because it’s time to cut the shoulders and the haunch. What’s a haunch? It’s an uncut part of the tenon that fills the 3⁄ 3 8" x ⁄ 8" groove you’ll soon make for the panel in both the rails and stiles. To cut the haunch you could readjust the fence and perhaps take a couple

chippers out of your stack. What a pain. Instead, I take piece of 3⁄ 8"-thick scrap and attach it to my fence. Then I run the rails on edge on one side (see photo). Instant and perfect haunch. Now remove the 3⁄ 8"-thick scrap from your fence and cut the shoulders on the other edge. Lay out the locations of all the mortises using the tenons you just cut.

Supplies Rockler 800-279-4441 Non-mortising hinges #31300 • $8.29 a pair. 2 wooden knobs

Machining Mortises Mortising is the most straightforward part. You want your mortises to be centered on your stock and about 11⁄ 16" deep. The little extra depth ensures your tenons won’t bottom out in your mortises and makes a place for the excess glue to go.

Top nailed into 1/4" x 3/4" dado

Face frame dimensions 1/2" 4"

44"

Case dimensions 1/2"

When you use a mortising machine, here are a couple of good rules that aren’t in most manuals. First, don’t cut the holes so they overlap. You want to make a hole, skip a small space and then make your next hole. Then come back and clean out the waste between the holes. 1/2"

12" 10 3/4"

3/4"

Face frame dimensions 1/2"

3/4"

3/4"

47 1/4"

47 1/4"

80 1/2"

80 1/2"

3/4" 3/4"

3/4"

18 1/2" 26"

26"

3 1/2" 1 7/8" 3 3/8"

3/4" 4 1/2"

1 1/2" 2 1/2"

1/2"

6" 3/4" 2 1/2" 3/4" Case dimensions

1 66

3/4" 4 1/2"

3" radius 12

1/2"

2 1/2" 38 1/2" 41 1/2" ELEVATION

12 1/2"

3/4" 2 1/2" 3/4"

Face frame dimensions

1/2"

16 3/4"

3/4"

18 3/4" PROFILE

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To cut the haunch, keep the same setup on your table saw and merely add a 3⁄ 8"-thick spacer to your fence. Run the rail on edge and your haunch is cut.

I use a dado stack in my table saw to cut the 3⁄ 8" x 3⁄ 8" groove on the inside of the rails and stiles. Take care that you center the groove.

Here I’m cutting the tenons on the rails. Use the fence to limit the length of the tenon.

tising bit to the bottom of the mortise in short strokes while moving the stile in small increments. This will get rid of most of the junk at the bottom of a mortise and prevent you from having to clean up your work with a chisel.

This prevents your mortising chisel from deflecting or even breaking during a plunge cut. Second rule: after you make the mortise, go back and clean out the bottom. I do this by repeatedly plunging the mor-

The Panel To fit the panels, the first step is to cut the 3⁄ 8" x 3⁄ 8" groove on the inside edges of the rails and stiles to hold the panel. I use a dado stack in my table saw to accomplish this quick chore. Adjust the

height of the blade until your haunch fits into the groove snugly. Now dry-assemble the stiles and rails and measure the opening for the panel. Add 1⁄ 2" to the height and width and that’s the finished size of your panel. Cut your panel to finished size on your table saw. If you want a flat panel door without a raised detail, simply cut a 1⁄ 4" x 1⁄ 4" rabbet on the backside of the panel (as shown in the drawing on the previous page) and move on to assembly. If, however, you want that beveled edge on your panel to add a shadow line, you need to do a little more fiddling. The end result is to create a bevel on the panel that is about 11⁄ 2" wide, at about a 12° angle and that fits snugly into the groove you cut in the rails and stiles.

Cherry Stepback NO.

❏ ❏

2 1

ITEM

DIMENSIONS (INCHES) T W L

MATERIAL

Sides

3⁄

4

171⁄ 4 80

Cherry

Top

3⁄

4

111⁄ 4

Cherry

39

1

Bottom

3⁄

4

17

1

Countertop

3⁄

4

181⁄ 4 411⁄ 2

3

Shelves*

3⁄

4

10 3⁄ 4 381⁄ 2

4

4

37

Cherry

4

11⁄ 2

37

Cherry

4

7⁄

8

37

Cherry

1⁄

2

48

1

Top FF rail

3⁄

1

Mid FF rail

3⁄

Lower FF rail

3⁄

4

1

2

Top stiles

3⁄

❏ ❏

2 2

Lower stiles Door top rails

3⁄

4

3⁄

2

Door bot rails

❏ ❏

4 2

1⁄

1 2

4

39

Cherry Cherry Cherry

Door rail Tenon

Cherry

4

21⁄ 2 311⁄ 4 21⁄ 2 141⁄ 2

Cherry Cherry

3⁄

4

31⁄ 2 141⁄ 2

Cherry

Door stiles Door panels

3⁄

4

5⁄

8

21⁄ 2 241⁄ 2 13 19

Cherry Cherry

Bot moulding

3⁄

4

51⁄ 4

84

Cherry

Top cap

1⁄

2

3

90

Cherry

Back boards

1⁄

2

391⁄ 2 76

Cherry

Haunch Groove

Door stile

Tenon shoulder Rabbet

Groove

Flat panel

* shelves have a dropped edge on the front.

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If you’ve got a shaper or a router table with a big variable-speed router, you can buy a panel-raising bit for just this purpose. When you cut the bevel on the edge, don’t do it all in one pass. Instead, take several passes to get you where you want to be. Or, better yet, cut most of the meat off using your table saw, then make the bevel cut in one pass on your shaper or router table. When making the cut on the router or shaper, cut the profile on the top and bottom of the panel first, which is where you’re most likely to have the ends blow out. Then follow up by cutting the profile on the sides. This should clean up any tear-out. If you want to raise the panel using your rip blade in your table saw, set the blade’s height for 11⁄ 2" and tilt the blade about 12° away from the fence (you might have to move your table saw’s fence to the other side of the blade to accomplish this). Now move the fence up to the blade and make several test cuts on a piece of scrap until you’ve nibbled away just enough so the bevel fits in the groove. You want the bevel to snuggle into that groove so there’s a 1⁄ 8" gap between the edge of the panel and the bottom of the groove. This will give your panel room to expand and contract. Dry-fit your doors to make sure everything goes together. Before you glue up the door, sand the bevel. I use a random-orbit sander with great care. You can hand-sand the bevel, but it will take considerably more time. Finishsand the backsides of the panels all the way to your final grit. 1 68

Assembly The trick here is to glue only the mortise-and-tenon joints, not the panel. Put glue in the mortises and clamp the door. Don’t overtighten the clamps; you can easily twist the door. When the glue is dry, sand the rest of the door. Because the panel will expand and contract with the seasons, I like to add a bit of insurance to the door to make sure the panel won’t slide around too much when it shrinks. The insurance is two brad nails. I nail the panel to the rails through the groove at two locations on the back of the door. One nail goes at the center of the top rail and one nail in the center of the bottom rail. This will still allow the panel to expand and contract, but it will keep it centered.

I like to cut most of the bevel on the raised panel on my table saw (left). Then I use a vertical raised panel bit in my 11⁄ 2 hp shaper to cut the profile in one pass (above).

To save time and effort, I glue up the panel for the countertop from two boards so it will fit perfectly into the dadoes in the sides.

Building the Stepback: A PLAN OF PROCEDURE 1. Cut all your stock to size; glue up any panels you might need. When gluing up panels for the sides, use one board that is 111⁄ 4" wide and 80" long, and one board that is 6" wide and 311⁄ 4" long. Glued together on edge, these form the corner where the countertop goes. Use the same procedure for the countertop. 2. Build your face frames for the upper and lower cabinet using mortise-and-tenon joinery. 3. Build your doors using mortise-and-tenon joinery. 4. Cut 1⁄ 4"-deep dadoes in the sides to hold the bottom, top and countertop. Cut a 1⁄ 2" x 1⁄ 2" rabbet on the back of the sides for the back pieces. Drill holes for the adjustable shelf pins. 5. Nail and glue the top and bottom pieces between the sides. Nail the face frames to the case. Slide the countertop in place and glue and nail. 6. Cut solid wood pieces for the shiplapped back. Finish sand all pieces. 7. Hang the doors. Nail commercially available crown moulding in place. Add a 1⁄ 2" cap on top. Stain or dye all the parts then add three coats of a clear finish. 8. Nail the shiplapped back in place.

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CHAPTER • 36

Make Accurate Half-Lap Joints B Y B I L L H Y LT O N

A half-lap joint is strong, versatile and easy to cut. You simply cut recesses in both mating pieces, then nest them together, forming an X, L or T. Half-laps can be used for all sorts of flat frames. Doors, for example, but also face frames, web frames and picture frames. An intermediate rail half-lapped to the stiles “looks” right because it visually abuts the stile (the way a mortise-and-tenon joint would) rather than crossing it (the way a bridle joint would). On the other hand, a rectangle of end grain is exposed in assembled end laps and T-laps (see diagrams on page 171), which can be regarded as unsightly. The half-lap can be used in postand-rail constructions to join rails or aprons to legs. You usually see this joint in worktables rather than fine furniture. But even in the most traditional table construction, the half-lap is used where stretchers cross (a cross-lap). From a practical perspective, the half-lap enjoys an advantage over the mortise-and-tenon joint in that one tool setup can suffice for both parts of the joint. (There’s more than one way to cut the joint, of course, and some do require two setups, as we’ll see.) You can join parts at angles quite easily. The joint accommodates curved parts, too. You can join curved pieces, or you can shape the half-lapped frame after it’s

The half-lap is made by cutting dados of equal width and depth on two pieces of wood so that the face surfaces are flush when assembled. Each piece is trapped between the shoulders of the other, so it’s a can’t-fail joint. The wood will break first.

assembled. Despite its simplicity, this joint is strong if properly made. The shoulder(s) resist twisting and there is plenty of gluing surface. But be wary of using half-laps on wide boards. Wood movement can break the joint, so confine the joinery to members no more than 3" to 31⁄ 2" wide. You can cut half-laps using several different power tools. Let the job suggest the tool to use and the way to use it, too. On the Router Table Everyone has favorite approaches, and mine involves the router. I cut end-laps

Photos by the author

on the router table using a lapping sled I originally made for tenoning. This shopmade device looks like a T-square on steroids (see the drawing at right). The stout fence is long enough to extend from the tabletop edge to well beyond the bit. The shoe rides along the edge of the tabletop. An adjustable stop clamps to the fence to control the length of the cut. Construction is simple, but pay attention to the details. The fence must be square to the shoe. The edge of the fence must be perpendicular to the tabletop. The adjustable stop also needs to be square to the fence. If any of these is off,

M A K E AC C U R AT E H A L F- L A P J O I N T S

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Adjustable stop

Cutting a half-lap on the router table is fast and accurate using a lapping sled to guide the work and a large-diameter mortising bit to cut it. The guide references the edge of the tabletop and a stop sets the length of the cut.

you won’t get consistently sized, squareshouldered laps. What bit to use? Well, a straight bit is the obvious choice, and it will work fine. I use what’s variously called a planer, mortising or bottom-cleaning bit. The several bits I have range in diameter from 3⁄ 4" to 11⁄ 2 ", and the vertical-cutting edges range from 7⁄ 16" to 7⁄ 8". The bit is designed to clear a wide, smooth recess. Perfect for laps!

The first time you use the lapping sled you’ll cut into the fence. This cut is what you use to position the stop for the length of lap you want. Measure from the shoulder of the cut (include the cut itself in the measurement, of course). The stop prevents you from making a cut that’s too long. Be mindful of the size of the cut and of the amount of material you will remove in a pass. You don’t necessarily want to hog out a 3⁄ 8"-deep cut in a single pass, especially if you are using a 11⁄ 4"- to 11⁄ 2"-diameter bit. You probably know there are two ways to moderate the bite: Reduce the depth of the cut or the width of the cut. Here, the most expeditious approach is the latter. Form the full cut in small steps. The first pass should be about 1⁄ 8" wide, produced by holding the workpiece well clear of the stop, so only 1⁄ 8" of the workpiece extends over the bit. Make pass after pass, shifting the workpiece closer and closer to the stop. One last pass with the workpiece dead against the stop and your lap is complete. This approach works well for end-laps,

Fences

Workpiece

To assemble a lapping platform, capture a workpiece between the fences and align the primary platform on them. The edge of the platform must be square to the work. You can build the simple version of this jig for cross-laps as shown in the photo or add a work stop as shown in the illustration to also cut end-laps.

Support platform

3" Main platform

Main platform

3"

1/2" 5/8"

8" Adjustable stop Work stop 2 3/4" 18"

3 1/2"

15 1/4"

5 3/4"

Fences

3/4"

Fence

Varies

1/2" 3/4" 7/8"

1 1/4"

LAPPING PLATFORM

1 1/4"

Carriage bolt “set screw“ see detail Shoe 13 1/2"

T-nut Adjustable stop

Jam nut

Fence

7/8"

Wing nut

LAPPING SLED SECTION, ADJUSTABLE STOP

1 70

Carriage bolt

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Main platform

Mating workpiece

Support platform

Use the mating workpiece as a spacer to position and align the support platform. Screw the support platform to the fences and you’re ready to get to work.

END-LAP/SCARF JOINT

but not for laps midway between the ends of the workpiece. For a cross- or a T-lap, the router table accessory to use is the dadoing sled shown in our April 2003 issue (# 133). You need to use a stop with this sled to keep the work from moving as the bit cuts it, and that helps you place the cut as well. Set the stop to position the final cut, and use a spacer between the stop and the work to position the first cut. Personally, I think it’s fussy to do Ts and crosses accurately on the router table. Given my druthers, I’d do them with a hand-held router and a jobspecific (and thus disposable) jig, such as the lapping platform shown in the drawing below.

Hand-held Router When cutting this joint with a hand-held router, I prefer a fixed-base router, rather than a plunge. I use the same planermortising bit, but I mount a pilot bearing on the shank of the bit. The lapping platform I make from four scraps and a dozen drywall screws. I use the actual workpieces to scale it. Begin by clamping the jig’s two fences to the edges of a workpiece. These fences need to be a bit less than the thickness of the workpieces and their edges need to be straight and parallel for the jig to work well. Next, set the main platform on the

END-LAP JOINT

T-LAP JOINT

Pilot bearing

Make the cut with a mortising bit with a shank-mounted pilot bearing. Trapped between the platforms, the bit produces a smooth, square-shouldered cut that perfectly matches the width of the workpiece.

workpiece and the fences. I usually use some 3⁄ 4" medium-density fiberboard for this, but plywood is OK for this application. Square it on the jig, then screw it to the fences. Finally, lay your mating workpiece across the first, tight against the platform’s guiding edge. Set the support platform in place and clamp it tight against the second workpiece. Screw it to the fences. The gap between the platforms is the width of the lap. It is easy to position: You just set the platform edges directly

CROSS-LAP JOINT

END-LAPS FOR CIRCULAR WORK

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on your layout lines. The bearing rides along the edges of the two platforms while the bit just below it excavates the lap. The bit is trapped, so you won’t get a lap that’s too wide. The fences tight against the workpiece edges prevent tear-out. The platforms support the router and keep it from tipping. Assuming the workpieces are equal in width, you can use one jig on both. I’m touting this for T-laps and crosslaps, but you can use it as well for endlaps. For this use, add a fifth scrap as a work stop. Attach it to the underside of the support platform so the workpiece end can butt against it.

Sawing Half-laps Not everyone is as enamored of router woodworking as I am, of course. Saws such as the band saw, the table saw, the radial arm saw, the sliding compound miter saw and, yes, even the carpenter’s workhorse – the circular saw – all can be used. Doing the job with a circular saw or miter saw is a “wasting” process. You adjust the saw’s cut depth to half the stock thickness, carefully kerf the margin(s), then waste the material between the margins with lots and lots of kerfs. Typically, you get a ragged cheek. It has to be smoothed somehow to glue well. But if you’re using a circular saw, you are probably doing something rough, where nails or screws work as well as glue. The band saw roughs out end-laps very quickly, but it leaves you with a rough surface that needs to be flattened and smoothed to glue well. Some woodworkers opt to rough out half-laps on the band saw, then finish them with a router. To me, that’s extra setups and extra work. Besides, you’ll be hardpressed to effectively band saw a lap that isn’t at the end of a workpiece. The radial-arm saw can be an effective tool for half-laps. Set up with a dado head, a well-tuned radial-arm saw will cut end- and cross-laps quickly and cleanly. You can see your layout lines, so locating the cut precisely is easy. You can do angled laps easily; just swing the arm right or left for the cut. You can set stops 1 72

Set the height of the blade to half the stock thickness and cut the half-lap shoulders. Cut the cheeks using a tenoning jig – this one is shopmade. For the cut, adjust the blade to match the width of the stock. Position the jig and the work so the waste falls to the outside of the blade.

Gluing up a halflapped frame requires the usual complement of pipe or bar clamps to pull the shoulders of the joints tight. Each joint also requires a C-clamp or spring clamp to pinch its cheeks tight together.

to expedite production jobs. The table saw gives you some options. You can use your everyday saw blade or a dado head. Guide the work with the miter gauge, a cutoff box or a tenoning jig. I’m sure you can figure out how to use the dado head with either a miter gauge or the cutoff box. This is the fast, single-setup approach on the table saw. But if you don’t have a dado head or you don’t want to switch from blade to dado set, you can use the blade with a tenoning jig to cut the laps. The routine is to saw the shoulders using the miter gauge, then saw the cheeks using the tenoning jig. The cut depth on the shoulder cut is critical, of course. If you cut too deeply, you will have a kerf that shows on the edges of the assembled frame. If you cut too shallow, it isn’t ideal but you can cor-

rect this with the following cheek cut. Use whatever tenoning jig you have for the cheek cut. Delta’s block-of-iron model is great, but I don’t think it works any better than the shopmade fencerider I use. Mount the jig on the saw and position it for the cut, adjust the blade height and saw those cheeks, one after the other. Assembly It’s not difficult to assemble a frame joined with half-laps. You must apply clamps to the individual joints, however, in addition to using clamps that draw the assembly together. Use bar or pipe clamps to pull the joints tight at the shoulders. Then squeeze the cheeks of individual joints tight using C-clamps or spring clamps.

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CHAPTER • 37

Mitered Half-Lap BY GLEN D. HUEY

One of the strongest joints in woodworking is a properly fit mortise-andtenon and the opposite in strength is a simple butt joint. For years I built base frames with mortise-and-tenon joints at the rear and mitered corners at the front. The miters were joined with biscuits. The rear joints were much stronger, so I wanted to add strength to those mitered front corners, but how? Not with mechanical fasteners; screws were out. I needed something quick to create and when assembled, I wanted the joint to retain a mitered look. The answer was a mitered half-lap joint. With a half-lap, there is plenty of flat-grain glue surface, and that increases the holding power, big time.

Tools for the Task Quick means simple in my book, so if a bunch of tools are needed, forget it. Goodbye, handtools. The process I came up with works with a router, a straight bit and a piece of plywood that’s a couple inches wider than your workpiece and long enough so it’s easy to add clamps. Trim one end of the plywood to a 45º angle to make things easier. With this technique, the router sits on top of the workpiece and kisses the fence on the final pass. It’s best to have a straight edge on your router’s base plate, or make sure you have accurately adjusted a round base plate so the bit is centered. An off-center base plate, depending on how you hold the router each time it’s picked up, allows the possibility that you’ll miss the layout line as you plow out the waste.

The straight bit can be any straight bit that you have in your arsenal. You’re only going to use the end of the bit, so even a top-mount bearing-guided bit works. A smaller-diameter bit is a bit easier to use, but because the cut is most often 3⁄8" in depth (half the thickness), a larger diameter bit is no problem. Keep the Players Straight To begin, cut your pieces to their finished length. For a base frame, miter the ends of the front rail at 45º – the adjoining returns are left square. Chuck a straight bit into the router and set the depth of cut very shallow.

Mitered joints are a common woodworking joint. Most are splined or joined with biscuits and lack real strength. With a quick setup that uses your router, you can master the mitered half-lap. When assembled, this joint rivals a tightly fit mortise-and-tenon.

NOT OFTEN CONSIDERED.

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GET IT EXACT.

The key to this technique is accuracy. Find the precise offset measurement through a sample cut to ensure you’ll have a perfect fit.

OFFSET AND GO.

If you’re comfortable with your router abilities, remove waste using a climb-cut, as well as in the traditional left-to-right manner.

IT’S A KEEPER.

NIBBLE AWAY.

Grab a couple pieces of scrap and position one on top of the other leaving a few inches to the right of the top piece, as shown above right. This makeshift fence allows you to find the exact offset from the edge of your base plate to the edge of the straight bit. Make one pass with the base riding along the fence then measure the distance from the fence to the dado. This is the offset measurement. Remember it. Layout is key. Form the half-lap on the wrong face of the pieces and you’ll lose the mitered look, so mark the faces to remove the bottom half of the mitercut end and the upper half of the squarecut ends. Draw an angled line (45º) on the squared ends beginning at the corner then square a line across the mitered ends beginning at the edge of the cut. Draw a second line, offset by the earlier measurement (the one I told you to remember), that’s parallel to the first lines. Position your plywood fence at the 1 74

Whether it’s an angled line on a square end or a square line on an angled end, the offset line is king. Plus it’s where to position your fence.

With accurate layout and routing, the completed portion is perfectly cut to accept its half-lap mate.

second layout line with the angled end toward the mitered end of your workpiece. Hold the fence flush with the bottom edge of the workpiece then clamp the fence in place. After you adjust the bit to remove half the thickness of your workpiece, nibble away the waste beginning at the end of the workpiece and working toward the plywood fence. On your last pass, hold the router base tight to the plywood. At the end of the cut, the router base plate hangs mostly off the edge of the workpiece, so maintain pressure to keep the plate tight on the workpiece. To clean the bottom waste from the miter-cut piece, align your fence with the square offset line, hold the bottom edge flush with the workpiece then nibble away the waste. Work slowly from the point to the fence. With the waste material removed from both workpieces, your joint will slip together with both shoulders tight.

OH THE PRESSURE. It’s easy to allow the router to tip into the cut portion as you work. Keep downward pressure on the base plate with one hand while steering the router with other.

The increased glue surface adds strength to the joint and when viewed from the top, the joint appears to be mitered. This is a great technique for base frames, picture frames or anywhere else your woodworking calls for a mitered corner.

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CHAPTER • 38

Lock Joints B Y B I L L H Y LT O N

The Best Bit to Use While the routed drawer-lock joint can be produced with two kinds of bits, I am going to focus on the more familiar one, which I call the drawer-lock bit. This bit is about 13⁄4" in diameter with a low body (about 1⁄2" high). Each cutting edge has a protruding tab to cut a single dado. The other bit you can use is a miniature glue-joint bit. It’s smaller in diameter (about 1") and the body is taller, about 3⁄4". It’s designed to produce a routed glue joint on thin stock. While the joint produced is stronger, thanks to the extra shoulder it produces, and it can also cut a glue joint on solid-wood stock, I prefer the drawer-lock bit. It’s easier to set up and will cut all the joinery you need to make a drawer, including the groove you need to hold the bottom in place. Neither bit has a pilot bearing, so you

Photos by the author

A couple of hundred years ago, most drawers were assembled with hand-cut dovetail joints – half-blinds up front, through dovetails at the back. But it’s the 21st century now. Many of us don’t have time to hand-cut dovetails. We want something that can be cut fast, assembles quickly and, of course, will stay strong. The drawer-lock joint is just the ticket. It has an interlock that holds the front and back to the sides and it resists the main stresses administered to a drawer – tension, compression and racking. The finished drawer might not have the pizazz of one assembled with dovetails, but it goes together a whole lot faster.

Two ways to cut a drawer-lock joint: The joint at top was made using a drawer-lock bit; the one at bottom was made using a miniature glue-joint bit. Both are strong and quick to make.

must do the work on a router table using a fence. Because the bits are small, you can use either in a low-powered router run at full speed. Both bits work the same way. One height setting is used for all cuts. The fence is used in one position for the fronts and backs, and in a slightly different position for the sides.

Setting Up the Drawer-lock Bit Start by setting the bit about 3⁄8" to 7⁄16" above the tabletop. As you slide the fence into position, either adjust its facings for zero clearance or apply a strip of 1⁄8"-thick hardboard to it (put the

Two bits will cut a drawer-lock joint. The miniature glue-joint bit (left) is less flexible on stock thickness but produces a joint with more interlock. The drawer-lock bit (right) is more flexible in terms of the thickness of wood it works with. It cuts joints for both bottoms and corners.

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If you’re using a miniature glue-joint bit, tweak the fit by adjusting the height of the bit. The point where the front meets the side must be tight.

hardboard in place with the bit running so it cuts through, creating your zeroclearance opening). Adjust the fence so it’s tangent to the bit’s small cutting diameter – just the tab should protrude from the fence. Make cuts in the edges of two pieces of your stock, turn one over and fit the two together. While the pieces won’t be flush, the interlock should be nice and tight (as shown in the photo at the top of page 28). If the fit is too loose, raise the bit to tighten the joint. If the fit is too tight, lower the bit. After each adjustment, make additional test cuts to check the fit. The only subsequent alteration you’ll need during setup is to shift the fence back when you cut the fronts and backs to expose more of the bit. Use a piece of the side stock as a gauge. Hold it on end against the fence and move the fence until the protruding tab is flush with the exposed face of the stock. It’s easy to move back and forth between cutting sides and cutting fronts or backs. Check out the series of photos below to see how I make these cuts.

Cutting the Joinery Before cutting the joinery for your drawer parts, mill your stock to the final thicknesses and lengths. To determine how long to cut the pieces, especially the sides, make sample cuts in scraps of the working stock. The thickness of your stock will have an impact on this. If you’re using 1⁄2" 1 76

Test cuts, made with the stock flat on your tabletop, help you zero in on the correct height setting of the drawer-lock bit. If the samples won’t mesh (top), the bit must be lowered. If they are gappy (bottom), the bit must be raised. When the setting is right (center), the joint closes tight.

Small diameter Large diameter

To rout the sides, set the fence tangent to the small diameter of the bit, leaving just the tab protruding. Check the setting with a rule.

Stand a side on end, braced against the fence, and feed it past the bit. The zero-clearance tabletop and fence surfaces minimize tear-out and prevent catches in the work’s movement.

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stock, for example, the sides generally will be about 1⁄8" shorter than the desired drawer length (front to back). Figure out what it’s going to be before crosscutting the parts and routing the joinery. A workable routine is this: • Rout the sides. To cut a side, stand it on end with the inside face against the fence and slide it past the bit. Cut one end, then the other. I’ve never found a tall fence to be necessary, nor do I bother with featherboards. If you’re more comfortable with these accessories, feel free to use them. • Rout the fronts and backs. First, adjust the fence position. The workpiece will rest flat on the tabletop with its end butted against the fence. A square scrap used as a back-up block helps keep the work moving squarely and smoothly along the fence. Bear in mind here that the thickness of your stock doesn’t impact the joints’ fit. You can mix 3⁄4"-thick fronts with 1⁄2"-thick backs, routing all with the same setup. • Rip the parts to their final widths. • Rout the groove for the bottom. Return the fence to the place used to cut the sides. Position the inside face of each part against the fence and cut from end to end with the drawer-lock bit just as it is set. This groove won’t be visible after assembly. • Mill the bottom so it fits the groove. Keep the bit and fence setting as they are. The 1⁄4" bottom should be face-down on the tabletop as you cut this rabbet.

Putting it All Together Assembly is pretty straightforward. After doing a dry fit, apply glue to the joints and put the parts together. I glue a plywood bottom into place, regardless of the stock used for the sides, front and back. In keeping with the “make ’em fast” mind-set, I’ve taken to shooting two or three brads into each joint. Glue holds the parts together, but the brads eliminate the need to clamp up each drawer, saving a lot of time. To do this, first join a side to the front. Then set the bottom into its grooves and add the back. Next, drop

Back-up block

Lay a drawer front or back flat on the tabletop, its end butted against the fence, then feed it past the bit. A back-up block minimizes tear-out and helps keep the workpiece square to the fence.

With the drawer bottom face-down on the tabletop, rout all four edges. The rabbet will fit the bottom to the grooves cut for it in the fronts, sides and backs using the same bit.

the second side into place. Check for square, shoot brads into the two remaining corners and your drawer is assembled and ready for fitting. If you don’t have a pneumatic brad nailer, you can use masking tape to “clamp” small drawers. But if you’re making larger drawers, you ought to use parallel-jaw clamps or bar clamps. Just apply pressure from side to side; frontto-back clamping is unnecessary. In the end, when the drawer is fitted to the case, shellacked and loaded up with whatever you’ve decided to store there, it’ll perform as well as the ones you devoted hours crafting with dovetails. And the proof is in the performance, right? The drawer-lock joint works on inset drawers with integral fronts (shown here) as well as on drawers with lipped false fronts.

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CHAPTER • 39

Loose-tenon Joints B Y B I L L H Y LT O N

I may be a power tool kind-of-guy, but I still favor traditional joints, those proven through centuries of use. The mortise and tenon is one of those joints. It has been in use for hundreds, if not thousands, of years, with examples found in ancient Egyptian furniture. I’ve pretty much settled on loosetenon joinery as my mortise-and-tenon variant of choice. Just about anywhere you’d use a traditional mortise-andtenon joint, you can use a loose-tenon setup. I’ve used it for commonplace frames, post-and-rail constructions and leg-and-apron assemblies. I’ve also used it to reinforce cope-and-stick joints. A loose-tenon joint is created by cutting mortises into both mating parts, then using a separate strip as a tenon to link them. With a horizontal boring machine, this joint is a cinch, but that’s not a common shop tool. And a hollowchisel mortiser isn’t specifically designed to do end mortises. My approach hinges on a plunge router, a quality edge guide and a shopmade mortising jig. Overall, this system satisfies me in terms of initial cost, ease of setup, accuracy and versatility.

Setup Convenience How’s this for simplicity? I lay out one mortise to set up the jig, the router, then the edge guide. Even that is rudimentary – just use the ends of the mortise and its centerline. The other edge mortises simply are marked using the mortise centerline. One end mortise must be delineated by a centerline, but the others don’t need any layout at all. 1 78

A plunge router, an edge guide and a shop-made jig are the foundation for loose-tenon joinery.

And how’s this for a simple work sequence? Set the workpiece on the jig’s workrest, align the mortise centerline on it with the setup line on the jig and clamp it. Set the router on the jig and rout, plunging progressively deeper as you move the tool from stop to stop on the jig. When the router is bottomed against its plunge stop, the mortise is complete. Unclamp the workpiece and realign it (or switch pieces) to rout the next one. Switching from edge-mortising to end-mortising requires only a workrest swap. Nothing else changes. When I’m doing rails and stiles – making doors or web frames, for example – I’ll rout all the edge mortises in the stiles, then switch workrests and rout the end mor-

tises in the rails. With all the mortises routed, making tenons is a matter of resawing and planing strips of suitable stock to fit. Rip the stock to width, round the edges on the router table, then crosscut the individual tenons.

Joint Design More often than not, I scale a joint as I’m laying it out. If I’m making the joint in a traditional manner, I’ll use a uniform shoulder width all around the tenon because it’s easy to cut. With a loose-tenon joint, I can make the end shoulders wider and it has no impact on cutting the mortise or the tenon slips. In general, the tenon should be as wide as possible. Remember, though,

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My mortising jig consists of a mortising block with separate, bolt-on router stops and two workrests. The horizontal workrest (with the toggle clamps) is for edge-mortising; the vertical one is for end-mortising.

Fixture centerline

Vertical workrest

Horizontal workrest

Align the centerline of the mortise with the red setup line on the jig. After the jig, router and edge guide are set up, the centerline is the only layout marking you will need.

that wood moves across the grain. So the wider the tenon is, the more it’s going to move (that’s true whether the tenon is a separate piece or is integral). The mortise, on the other hand, isn’t moving at all. The resulting cross-grain stresses can bust the joint. If you need a very wide tenon, divide it into two or more equal parts. (And when you glue that joint, by

the way, put the glue on only one tenon.) In practice, for a door frame I’ll use a rail to mark the joint location, scribing along its edges on the stile edge. From those marks, I’ll measure in to locate the ends of the mortise. (Whether the ends are equal distances from the edges isn’t relevant.) To complete the setup, measure from shoulder to shoulder, divide

B Router stop key

Holes drilled and tapped for workrest

Guide slot for router stop Fixture centerline E Router stop B

Guide slot for vertical workrest

the distance in half and mark the mortise centerline. I usually make the mortise width half the stock thickness. This yields a well-balanced joint, with half the overall thickness allocated to the mortise and half to the tenon. But how deep should you make the mortises? The critical half of the joint A) MORTISING BLOCK. This is the body, composed of a 11⁄ 2" x 9" x 16" block, with an extra support strip and a clamping pad glued to the back face. The block’s face has keyways and mounting bolt holes for the workrests. It’s critical that the top surface be perpendicular to the face. B) ROUTER STOPS. The travel of the router along the mortising block is limited by the two stops. A key dadoed into the underside rides in a groove in the block top. The mounting bolt passes through a slot, which allows for easy adjustability. C) EDGE GUIDE TRACK. A

Edge guide track C

A

Clamping pad

Mounting bolt slots

Guide slots for horizontal workrest Horizontal workrest D

ROUTER MORTISING JIG

facing attached to the edge guide catches in the track, preventing the router from drifting off course. (To cut twin mortises, expand the width of the track and use a spacer next to the facing. Put the spacer on the inside and the bit is close to the block face. Switch the spacer and put it on the outside and the bit shifts away from the block.) D) WORKRESTS. Horizontal

and vertical rests hold the workpiece for mortising. Mounting bolts passing through the slots allow for adjustability; keys keep the rest either parallel or perpendicular to the block top as you adjust its position.

E) FIXTURE CENTERLINE. All

of your equipment setups and workpiece alignments pivot around this line. On my jig, the line is red.

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is in the stile or leg, where the tenon’s grain runs perpendicular to that of the mortised piece. Wood movement may actually make a long-tenon joint weaker than a short-tenon joint. The best compromise? Mortise about half the stile’s width, a bit more in narrow pieces. For example, rout the mortise 11⁄ 2" deep in a 3"-wide stile, but rout it 1" deep in a stile that is only 11⁄ 2" wide. In the other half of the joint – the rail or apron – the grain of the tenon slip is parallel to that of the mortised piece. Depth is less of an issue, so I rout this mortise to the same depth as its partner in the stile or leg.

Setting Up The mortise width is established by the diameter of bit used, while the mortise depth is controlled by the plunge of the

Position the bit at the mortise’s end mark, slide the stop against the base of the router and secure the stop. Then repeat this at the other end.

router. The length is governed by stops on the jig. And the alignment of the mortise on the work’s edge is controlled by the edge guide. With the mortising block clamped to the bench and the horizontal workrest mounted, set the piece on the workrest and align the mortise midpoint with the setup line on the block. Clamp the piece to the jig. Secure the bit in the router collet. Attach the edge guide to the router, set the router on the mortising block and, by eye, adjust the edge guide to center the bit across the stock. (We’ll do a test cut and fine-tune this setting momentarily.) Bottom the bit against the workpiece and set the plunge depth to equal the desired mortise depth. Set up the router stops next. Move the router to the left, aligning the bit inside the mortise boundaries at the mark. Slide the stop up to the router base and tighten the bolt. Move the router to the right, again aligning the bit at the shoulder mark. Position and lock the second stop. I like my mortises to be centered on the thickness of the stock. This simplifies and expedites the routing, and it eliminates a lot of problems and frustration that can arise during final assembly. To do this, make a shallow test cut in the layout piece. Mark the outside face

of the work (so you know which direction to adjust the setup) and remove it from the jig. With dial calipers, measure the widths of the shoulders. Subtract the narrow width from the broad width and move the bit half the difference toward the narrow shoulder. I use the MicroFence – a fence so good I’ve even done some work for the company (800-480-6427 or microfence. com) – which has an adjuster calibrated in thousandths so this fine adjustment is manageable. If you’re working with a less-precise guide, there are two ways to work around it. • First, you can choose to mark a reference face on each workpiece, orienting that face the same way in relation to the mortising jig. When you assemble the work, orient the reference faces the same and all the parts will be cut flush. The drawback to this method arises if the centerlines of the end mortises aren’t congruent to the work’s centerlines. Maybe one end is 1⁄ 4" from the edge, the other 1⁄ 2". To fix this, you either have to shift the workrest position for half of the

Wooden facing

The wooden facing on the edge guide drops into the channel at the back of the jig, allowing you to move the router back and forth without worrying if it will wander off course. The stops control the router’s travel, ensuring the mortise will be the correct length.

1 80

Here I’m cutting twin mortises. A spacer shares the channel with the edge-guide facing. With the spacer between the jig and the facing, the router can cut the first mortise. Moving the spacer behind the facing bumps the router out, so it can cut the next mortise.

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Switching the jig for end mortises is a matter of removing the horizontal workrest and replacing it with the vertical one. Clamp a rail to the jig with its centerline aligned with the jig’s setup line to locate the workrest while you secure it. Nothing else changes in the setup.

end mortises or you must use a spacer between the work and the workrest for half. Either way, it’s more work. • Another option is to rout every mortise twice to center it. Start by routing a mortise. Then turn the workpiece around on the jig and rout it again. This is an extra step and widens the mortise, of course, but it also produces a uniform shoulder width.

Routing the Mortises Dialing in the edge guide is the final step. Once that’s done, routing the mortises themselves is almost anticlimactic. Almost. You want to excavate the mortise quickly by making a series of light cuts. Ideally, you want to plunge the bit into the work, feed quickly to the far stop and then retract the bit from the cut as you return the router to your starting position. (Note that if the edge guide’s facing is in the jig’s edge-guide track, you can feed the router either way without consequence.) You don’t want the bit to dwell in the cut because that generates heat, which can dull the router bit and scorch the wood. Scorched surfaces don’t glue well. (Note: Using a router with dust extraction is good in this regard. Chips packed in the cut around the bit retain the heat. Pulling out those chips as they’re generated helps lower the temperature.) You can use the router’s adjustable turret to stage your depths, but that probably will feel like an intrusion – at least it does to me. Estimate the depth of each pass. If the feed resistance seems high and the bit chatter resonates (even when using hearing protection), then you need to back off. It’s most efficient to do all the edges, then swap workrests and do all the ends. Swapping workrests on my jig simply entails backing out a pair of mounting bolts. Nothing in the setup changes, so your end mortises will duplicate the edge mortises. End mortises generally involve no additional alignment. Tucking the work against the rest aligns it for the cut. What I’ve found is that the rubber tips of

The rubber tips of toggle clamps have too much give, so I use deep-throat clamps to secure the work for end-mortising.

toggle clamps allow the work to deflect when the bit plunges against it. As a consequence, I use a deep-throat clamp or two to secure the work to the jig for end mortises, as you can see in the photo above right. This works well.

Making the Tenons The common way to produce the loose tenons is to mill strips of stock to the appropriate thickness, rip the strips to width, round the edges with a roundover or small half-round bit and crosscut them to length. Some people rout grooves in their tenons to provide a reservoir for excess glue. You can save a step, and provide yourself with a little assembly flexibility, if you make the tenons square-edged. The critical gluing surfaces are the cheeks, not the edges. Eliminating the rounded edges doesn’t degrade the strength of the joint appreciably. It does provide a reservoir for the excess glue

and allows you to adjust the joint slightly as you assemble it.

The completed joint, ready for assembly.

LO O S E-T E N O N J O I N T S

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CHAPTER • 40

Four Good Ways to Cut Rabbets The rabbet joint surely is one of the first ones tackled by new woodworkers. The rabbet is easy to cut, it helps locate the parts during assembly and it provides more of a mechanical connection than a butt joint. I vaguely remember thinking, back when I was tackling my first homeimprovement projects, that with practice I’d outgrow rabbet joints. Well I’m still cutting rabbets because woodworkers never outgrow them. The most common form is what I call the single-rabbet joint. Only one of the mating parts is rabbeted. The cut is proportioned so its width matches the thickness of its mating board, yielding a flush fit. The depth of the rabbet for this joint should be one-half to two-thirds its width. When assembled, the rabbet conceals the end grain of the mating board. The deeper the rabbet, the less end grain that will be exposed in the assembled joint. In the double-rabbet joint, both the mating pieces are rabbeted. The rabbets don’t have to be the same, but typically they are. The rabbet works as a case joint and as an edge joint. Case joints generally

Depth = 1/2 to 2/3

of width

involve end grain, while edge joints involve only long grain. In casework, you often see rabbets used where the top and/or bottom join the sides (end-grain to end-grain), and where the back joins the assembled case (both end-to-end and end-to-long). In drawers, it’s often used to join the front and sides. Because end grain glues poorly, rabbet joints that involve it usually are fastened, either with brads, finish nails or screws concealed under plugs. (OK, in utilitarian constructions, we don’t sweat the concealment.) We don’t necessarily think of the rabbet as an edge-to-edge joint, yet we all know of the shiplap joint. Rabbet the edges of the mating boards and nest them together. Voila! It’s also a great right-angle edge joint. We see this in the case-side-and-back combination, but also in practical boxsection constructions such as hollow legs and pedestals. Long-grain joins long-grain in these structures. Because that glues well, you have a terrific and strong joint. You can gussy up the joint’s appearance by chamfering the edge of the rabbet before assembly. When the joint is assembled, the chamfer separates the face grain of one part from the edge

Photos by the author

B Y B I L L H Y LT O N

Saw a rabbet on the table saw in two steps. Set the blade elevation and fence position first to cut the shoulder (above) then adjust either or both as necessary to cut the bottom.

grain of the other. Because the chamfer is at an angle to both faces, it won’t look inappropriate even though its grain pattern is different. One important variant is the rabbet-and-dado joint. This is a good rack-resistant joint that assembles easL-shaped cuts made with or across the grain are called rabbets – whether they are on the end or along the edge of the stock.

Width

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ily because both boards are positively located. The dado or groove doesn’t have to be big; often it’s a single saw kerf, no deeper than one-third the board’s thickness. Into it fits an offset tongue created on the mating board by the rabbet. The rabbet-and-dado joint is a good choice for plywood casework because it’s often difficult to scale a dado or groove to the inexact thickness of plywood. It’s far easier to customize the width of a rabbet. So you cut a stock-width dado, then cut the mating rabbet to a custom dimension. An extra cutting operation is required, but the benefit – a big one – is a tight joint. There are lots of good ways to cut rabbets. The table saw, radial-arm saw, jointer and router all come to mind. The most versatile techniques use the table saw and router.

Rabbeting on the Table Saw Rabbets can be cut at least two different ways on the table saw. Which method

SINGLE-RABBET JOINTS

DOUBLE-RABBET JOINT

you choose may be influenced by the number of rabbets you have to cut, as well as the sizes and proportions of the workpieces. It’s quickest to cut the rabbets using whatever blade is in the saw. Two passes are all it takes. But if you have lots of rabbets to cut, or if the workpieces are too big to stand on edge safely, then use a dado cutter. (The latter is especially appropriate if your job entails dados as well as rabbets.) Let’s look at the quick method first. The first cut forms the shoulder. To set it up, adjust the blade height for the depth of the rabbet. There are a variety of setup tools you can use here, but it’s always a good idea to make a test cut so you can measure the actual depth of the kerf. That done, position the fence to locate the rabbet’s shoulder. This establishes the rabbet width, so you measure from the face of the fence to the outside of the blade. The cutting procedure is to lay the work flat on the saw’s table, then run the edge along the fence and make the shoulder cut. If you are rabbeting the long edge of a board, use just the fence as the guide. When cutting a rabbet across the end of a piece, guide the work with your miter gauge and use the fence simply as a positioning device. It is easy to set up, and the miter gauge keeps the work from “walking” as it slides along the table saw’s fence. Because no waste will be left between the blade and the fence, you can do this safely. Nevertheless, if you feel uneasy about using the miter gauge and fence together, use a standoff block. Clamp a scrap (your standoff block) to the fence near the front edge of the saw’s table. Lay the work in the miter gauge and slide it against the scrap. As you make the cut, the work is clear of the fence by the thickness of the scrap. (Try using a 1"-thick block to make setup easier.) Having cut the shoulders of all the rabbets, you next adjust the setup to make the bottom cut. You may need to change the height of the blade or the fence position. You may need to do both.

Clamp a sacrificial facing – a strip of luan plywood here – to your table saw fence when cutting rabbets with a dado head. Run the cutter up into the facing, exposing only enough of the cutter to form the rabbet.

Adjust the blade to match the width of the rabbet. Reposition the fence to cut the bottom of the rabbet, with the waste falling to the outside of the blade. Make that cut with the workpiece standing on edge, its kerfed face away from the fence. When the workpieces are so large as to be cumbersome on edge – cabinet sides, for example – you want to cut the rabbets with a dado cutter. That way you can keep the work flat on the saw’s table. Control the cut using a cutoff box or the fence. It’s very easy to set the width of the cut with this approach. Where the proportions of the workpiece allow it, use the rip fence to guide the cut. Clamp a sacrificial facing to the fence. Don’t fret about the width of the stack, so long as it exceeds the width of the rabbet you want. Part of the cutter is buried in the fence facing, and you just set the fence to expose the width of the cutter that’s working. Guide the work along the fence. Alternatively, use a cutoff box to support the work and guide the cut. You get the same advantages in rabbeting that you do with dadoing: The work really doesn’t move, the box does. Use a stop block to position the work to yield the width of rabbet you want. On the other hand, it may be a little more difficult to get exactly the cut width you want.

Rabbeting with the Router The router is an excellent tool for rabbeting, in part because you can deploy

F O U R G O O D WAYS TO C U T R A B B E T S

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it as a hand tool. For some jobs, you just want to immobilize the workpiece to your bench and move the cutting tool over it. In those situations, the router is the tool to use. Occasionally, you might want to cut a rabbet into an assembly – perhaps a frame for a door or lid. If you use a router, you can wait until the frame is glued up and sanded, then produce the rabbet for a pane of glass or a panel. You do have to square the corners, but that’s simple with a chisel. A major benefit of the hand-held router approach is that you can see the cut as it is formed. On the table saw (and the router table), the work itself conceals the cut. You can cut rabbets on the router table as well, of course. But I want to focus on hand-held approaches here. Cutting a rabbet on the router table is

With an edge guide and straight bit, you can customize the rabbet’s width, forming it in a series of passes.

SHIPLAP JOINT

quite similar to doing it on the table saw with a dado head. A rabbeting bit is the commonly used cutter, but it is not the only one that will work. If you use an edge guide to control the cut, you can use a straight bit or a planer bit. The rabbeting bit is piloted, and the typical bit makes a 3⁄ 8"-wide cut. Most manufacturers sell rabbeting sets, which bundle a stack of bearings with the cutter. Want to reduce the cut width? Switch to a larger bearing. The set I have yields six different widths from 1⁄ 2" to 1⁄ 8" (no 3⁄ 16"), and with the largest bearing the bit can do flush trimming work. The piloted bit enables you to rabbet curved edges. You can’t do that on the table saw. Making a cut with a piloted rabbeting bit is pretty much a matter of setting the cut depth, switching on the router and diving in. Cut across the grain first, then with the grain. If you are routing only across the grain, either climb-cut in from the corner or clamp a backup scrap at the corner to prevent blowout as the bit exits the work.

RABBET-AND-GROOVE (OR DADO) JOINTS

The bit and the bearings do work very well, but I’m often inclined to use an unpiloted bit with an edge guide for rabbeting. I get an infinitely variable cut width with this setup, rather than a few predetermined widths. In addition, I have better control over the tool and the cut. With a piloted bit alone, the cutting edges begin their work before the bearing makes contact with the edge. All too often, you dip around the corner of the workpiece at one end of the cut or the other. That doesn’t happen with an edgeguide-controlled cut because the guide surface extends well beyond the cutter both fore and aft. Keep the guide in contact with the workpiece edge throughout the feed – beginning before the cut actually starts and continuing until the bit is clear of the work – and you won’t run into trouble. The latter is especially true if you elect to circumvent blowout by climbcutting in from a corner. The guide gives you the good control needed for a climb cut. The edge guide is a big help in beginning and ending stopped or blind cuts as well. Brace the tip of the guide against the workpiece edge, shift the whole router as necessary to align the bit for the start of the cut, then pivot the router into the cut.

One bit with a selection of bearings enables you to cut rabbets of many different widths.

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C H A P T E R • 41

Right Time for Splines B Y B I L L H Y LT O N

Spline Materials Because the nature of the spline can have an impact on the method you use to cut the grooves, you should think about whether you want to use solid wood or plywood. Plywood is strong, because of its criss-crossing plies, and it is stable, meaning you can use it without worries about grain orientation. The primary reservation I have about plywood is with its thickness. It’s surprisingly difficult to cut a closely fitted groove for 1⁄ 4" plywood, which we all know ain’t 1⁄ 4". At the table saw, two passes with the same setup and with each side against the rip fence gives you a centered groove for an edge-to-edge joint. And you can use the two cuts to customize the groove

width. But when your narrowest cut is 4", as it is with a dado cutter, the plywood’s thickness is a concern. Even cutting with a 7⁄ 32" router bit doesn’t produce a good fit. A spline that’s poorly fitted can result in misalignment and a joint that’s weak. Solid wood splines are extra work, but you can customize the thickness to suit standard, easily-cut groove widths – 1⁄ 8", 3⁄ 16" or even 1⁄ 4". Moreover, if the spline is going to be visible, you can use either the working stock, so it nearly disappears, or a contrasting stock, so it’s more of an accent. Another thing to be wary of is the grain direction in the spline. The grain in the spline should run parallel to the grain in the mating parts, unless you’re using it in a miter. Then the spline’s grain should run perpendicular to the joint seam. 1⁄

Cutting the Grooves The primary tools for cutting the grooves are the table saw and the router, either hand-held or table-mounted. Boil down all the joint variations and you discover that you have two basic cuts: 1) into square edges and 2) into beveled edges. When you cut into square edges the setup steps are pretty routine for both the table saw and the router. • First, select a cutter. At the table saw, ask yourself if a pass with the standard blade (typically producing a 1⁄ 8" kerf) will be adequate. Do you switch to the dado cutter, with a minimum kerfwidth of 1⁄ 4"? Can you make successive passes with a careful setup to produce a

Photos by the author

If you want to increase a joint’s strength and simplify its assembly, I suggest adding a spline. It’s an enhancement that is often advocated for edge joints, but it is most appropriate in a miter joint. The process is pretty simple: You cut the grooves in the mating surfaces of the joint and as you assemble the joint you insert a spline, which bridges the seam and links the two pieces. The drawings below show the most common varieties. In the through spline, the grooves are cut from edge to edge and the ends are visible in the assembled joint. In the blind spline, the grooves end short of either edge, making the spline totally concealed in the assembled joint. A stopped spline is the compromise: visible at one end, concealed at the other.

A shop-made angle sled allows you to cut bevels and spline grooves on the table saw without tilting the blade. Clamp the work to the sled’s sloping fence and guide the sled along the saw’s rip fence to make the cut.

kerf width between 1⁄ 8" and 1⁄ 4"? At the router table, select either a straight bit or slot cutter, then choose the appropriate dimension of cutter. • Set the cutter. With your cutter selected and installed, you next have to adjust its height. Raise the saw blade or the straight bit to the depth you want for the spline groove. For the slot cutter, raise it to position the groove; the depth is controlled by the fence. Appropriate depths vary with the orientation. In a square edge, you can cut R I G H T T I M E F O R S P L I N ES

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Through spline

Blind spline

1/64"

Spline

clearance

1/8" 5/8"

SPLINED EDGE-TO-EDGE JOINTS

Start position Stop position

Blind slots for splines can be cut on the router table with a slot cutter. Remove the bearing from the cutter assembly so a zero-clearance facing clamped to the fence doesn’t rob you of too much cut capacity. Starting and stopping points are marked with blue tape. 1⁄

2" or more deep. Limit a cut into a face to about one-third of the board’s thickness. Edge-miters and end-miters should be limited so that you don’t weaken the stock. In 3⁄ 4" material, a 3⁄ 8"-deep slot is fine. • Set the fence. The fence guides the work and establishes where the cut will be. (The exception is when you use a slot cutter, as I just mentioned.) Position the fence, then check the settings with a test cut. • Establish a reference face. Mark

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each workpiece to ensure you are using the same face on each piece to index the cut. Otherwise, you’ll have misaligned slots. • Make the cuts. Through-cuts are straightforward, regardless of which tool you’re using. The table saw cuts to full depth in a single pass, as does the slot cutter. With a straight bit, limit the bite to about 1⁄ 8" per pass and plan on making two or three passes to complete a groove. Stopped cuts and blind cuts should not be done on the table saw. They can be done much more easily on the router table with either a straight bit or a slot cutter. Mark the starting and stopping points on the fence, align the end of the workpiece with the mark on the outfeed side and plunge it onto the cutter. Feed right to left until the trailing end lines up with the mark on the infeed side, then lift or pivot the work off the cutter. • End slots. Slotting the end of a workpiece can be very simple. A tall facing clamped to the router table’s fence can support the work for a straight-bit cut. Use a push block to keep the workpiece square as you slide it along the fence. If you’re using a slot cutter, the work rests flat on the tabletop. That’s a big benefit. On the table saw, you can use a tenoning jig to guide the cut. Regardless of your approach, it’s a good idea to use a zero-clearance insert around the cutter. You don’t want the work to catch on the cutter opening, whether that opening is in the fence or the tabletop. A flat miter is square-edged, though because of the angle you probably don’t think of it that way. The pitch of the piece probably will prevent you from using a tenoning jig, but you can mount a tall facing to your rip fence and use a push block, making the cut the same way you would on a router table with a straight bit.

Angled fence

Braces

Base EXPLODED VIEW

1"

11 1/4" 6"

7" 8"

All parts are 3⁄ 4" stock

PROFILE

16"

5 1/4" 1 5/8"

REAR VIEW

ANGLE SLED FOR TABLE SAW

Push block

Use an angled push block to back up a through-cut in a flat miter. A tall fence facing helps steady the work, and a zero-clearance auxiliary tabletop (an 1⁄ 8" hardboard covering for the tabletop) prevents catching the work on the bit opening.

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With a flat miter, your push block’s leading edge needs to be angled exactly like the miter. Your piece will be leaning forward when you slot one end, leaning back when you slot the other. Use the same push block for both cuts and just roll it over between cuts. • Stopped-end & blind-end cuts. Because an end slot is likely to be short even when it is through, making it stopped or blind presents real maneuvering challenges, regardless of the tool. This is a good place to use a biscuit.

Grooving Bevels The starting point for a successful splined miter joint – whether an edge miter or an end miter – is making accurate 45° bevels on the stock. After cutting all these, lay out the spline groove on one piece. To avoid weakening the tips of the bevels, you want to locate the spline slot very close to the joint’s inside corner. This allows you to make a 3⁄ 8"deep cut without weakening the stock. Decide how wide your slot will be. The spline doesn’t need to be very thick, and in most instances a single saw kerf is satisfactory. If you want the spline thicker, you’ll have to either use your dado cutter or kerf each piece, then reset the fence to widen the kerf. With an edge miter, place the fence so the blade tilts away. Feed the stock along it with the sharp edge of the bevel against the fence. With an end miter, use the miter gauge to guide the stock. (The rip fence can safely be used to position the work for this cut.) Place spline close to inner corner to limit weakening of case sides

DIAGONALLY SPLINED END MITER

Start

Stop

A stopped cut in a flat miter involves tipping the workpiece back and aligning it over the bit before plunging and feeding to the stop mark. Lay out the extents of the slot on the piece’s reference face and align them with marks transferred onto the tabletop from the bit to control the length of the cut.

Router Grooving Splined joinery isn’t the exclusive province of stationary tools. With a router and slot cutter, you can cut the grooves for most every splined joint. A few can be done with a straight bit and an edge guide. With a slot cutter, the router sets on the face of the workpiece while the cutter works the edge. To alter the cut depth with a slotter, just switch bearings. Installed in a small router, a slot cutter can groove ends and flat miters. Even edge miters and end miters can be grooved with this setup. Clamp two workpieces face to face so the bevels angle to the outside. Rest the router on one bevel and the slotter cuts a groove in the adjacent one, as shown in the photo at right. Assembly Fitting the splines comes next. Plywood splines are easy – you just cut them to width and length. If the spline is stopped or blind, the ends usually must be rounded to fit. A wood spline has to be measured for thickness, then ripped and crosscut to fit. Its ends sometimes must be shaped. For an end miter or flat miter, the spline’s grain should be perpendicular to the joint’s seam. Crosscut strips of a long blank and glue them side-by-side in the slot in one part, then assemble the joint. Assembly is usually uncomplicated. Just spread the glue, insert the spline, close the joint and apply clamps. The real payoff comes in assembling a miter joint. Typically, miters

Bearing

With the work sandwiched face-to-face, you can guide a trim router along one bevel while the slot cutter grooves the other bevel. Use an oversized bearing, positioned as shown, to limit the depth of the cut.

are difficult to get into alignment and, as clamps are applied, to keep in alignment. That is seldom the case when the miter is splined. The spline prevents the faces of the bevels from slipping and sliding, and you can apply clamps without extra alignment blocks or glued-on, tacked-on, clamped-on cleats for the clamps to grip. Ease-of-assembly is the whole point of the spline, and it really works.

R I G H T T I M E F O R S P L I N ES

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CHAPTER • 42

Tongue & Groove B Y B I L L H Y LT O N

A tongue-and-groove joint is an edge joint with a mechanical interlock. The edge of one board has a groove. A matching tongue is formed on the edge of the mating board. The tongue goes into the groove, and the boards are joined. You probably are most familiar with the joint’s many applications in building construction, such as strip flooring and paneling. In furnituremaking, the tongue and groove is excellent for edgeto-edge glue-ups. If cut precisely, the joint ensures that the faces of adjoining boards come flush easily and that they can’t creep out of alignment as you position and tighten clamps. When the clamps come off, a little scraping and hand-sanding is all that’s needed before moving on.

Cutting the Joint Consider the design of the joint before you set up to cut it. Good proportions are essential to produce a strong joint, but the intent of the joint also is important. The general rule says you should have a square tongue that’s roughly onethird of the stock thickness and centered on the edge. Working with 3⁄ 4" stock, that plays out to a 1⁄4"-thick by 1⁄4"-long When setting up the table saw to cut the joint, just eyeball the rip-fence position for the groove. Sight down across the end of the stock and align a centerline drawn on it with the center of the cutter. A two-pass work routine centers the groove and eliminates the need for test cuts. When making the joint (right), a snug press fit is your goal. This is a first try – honest!

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tongue, and a matching groove. A longer tongue (one that’s 1⁄2" long for example) is prone to break at the shoulder. Also, the walls of a deep groove may crack. But a tongue and groove for a panel glue-up – just to register and align the faces – requires only a small tongue. All it takes is 1⁄ 8". The joint should be a firm press fit: If you have to knock the pieces together, then struggle to pull them apart, the joint’s too tight. A tongue that’s a hair too fat for the groove may actually seat, but it will stress the groove sidewalls and may, in time, prompt them to split. On the other hand, you don’t want the tongue to rattle in the groove, especially where the joint is intended to register and align the faces during assembly. You can cut tongue-and-groove joints with a table saw, shaper or router, either hand-held or table-mounted. I’m going to focus on the table saw and the router. There’s no hard rule on which half of the joint you cut first. I prefer to make the groove first, because I think it’s easier to fit the tongue to it than the other way around.

On the Table Saw To produce a tongue and groove on the table saw, use a dado cutter rather than your everyday blade (unless your stock is 3⁄ 8" or less in thickness). I use the two outside cutters to produce a 1⁄4" cut width when working 3⁄4" stock. Thicker stock calls for a wider groove. Set the cutter height next – 1⁄ 4" to 3⁄ 8" is optimal for a joint that’s to be assembled without glue. If you’re mak-

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ing a glue joint, a shallow 1⁄8" groove is all that’s needed. Bring the rip fence into position, endeavoring to position it to center the groove on the working stock. Make a test cut and measure the groove shoulders with dial calipers. Adjust the fence setting to center the cut as close as possible, then center it by making two passes on each board. When you’re content with the samples, cut a groove on each workpiece. To switch to the tongue-forming setup there are no changes in the cutter height. Use a sample groove to position the fence, aligning the outside edge of the cutter with the edge of the sample’s groove as shown below. You will probably need a sacrificial facing on your fence, as shown in the photos at right. Cut a sample tongue and fit it to the groove. Slide the work along the fence, cutting one shoulder, then spin the work around and repeat the cut to form the second shoulder, as shown below. Adjust the fence position as necessary to get a good fit.

With a Router Using a router gives you more options in terms of the approach and the cutters. You can do the work on the router table or you can move a portable router across planted boards. If you’re going to use the former approach, you can cut tongue-andgroove joints with a straight bit, a slot cutter or a dedicated tongue-and-groove cutter assembly or set. If you want to use a portable router, then I’d recommend using the slot cutter. Using a straight bit: On the plus side, you use a commonplace bit that has a multiplicity of applications. On the negative side, you may, depending on the hardness of your stock, need to make more than one pass per cut to reach the full depth. That can trigger work sequence woes, especially on a job with lots of pieces. Specifically, you have to make a pass on each workpiece, adjust the cut depth, then make a second pass on each piece. Using a straight bit to cut a tongueand-groove joint in a portable router

A sacrificial facing on the rip fence preserves the dado cutter and the fence, yet allows cut width adjustment using the fence position. More than just a facing, mine straddles the fence; one out-of-the-way clamp immobilizes it.

Use a grooved piece to set the fence for the tongue cuts. Align the outermost cutter tooth with the inner wall of the groove. A test cut and some fine-tuning may be required at this stage to fit the joint properly.

A rabbet cut into each edge of the board forms the tongue. It’s smart to cut a sample and check its fit before cutting all your work.

requires balancing the tool on narrow edges, a tough assignment. Cutting the joint on the router table with a straight bit mimics using a dado cutter on the table saw. The cut controls are these: The bit’s extension above the tabletop governs the tongue length/groove depth. Fence position controls lateral placement of the cut. You cut both elements with the work on edge, with the face tight against the fence. The setup sequence and cutting routine also mimic those of the table saw approach: • Install the bit and set its extension. • Position the fence for the grooves.

With one end of the fence secured, swing the free end to align the centerline on a sample workpiece with the bit’s center. Auxiliary coverings on the fence and tabletop downsize or eliminate the bit opening to forestall workpiece hangups. • Rout the grooves, centering them most easily by making two passes. • Reposition the fence for the tongues. • Rout the tongues by making two passes on each workpiece. Using a slot cutter: An alternative, one that works equally well in tablemounted and portable routers, is the slot cutter. On the positive side, it will cut a full-depth groove easily. It’s a TO N G U E & G R O OV E

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When you’re using a straight bit, repositioning the fence for cutting tongues can be an optical challenge. Sight across the bit to the grooved sample to make an initial setting. Cut a sample tongue, and adjust the fence position if necessary based on a test fitting.

Two passes form the tongue. Note that the cut is on the fence side of the work. In addition, the table is set up to prevent stalled cuts. While not zero-clearance, the opening in the tabletop is minimized and the fence facing is seamless.

good choice for thin stock, because a variety of slot widths less than 1⁄4" are available. However, there aren’t single cutters available in widths greater than 1⁄ 4". To produce a wider-than-1⁄ 4" groove requires an assembly with two or more cutters on its arbor. When cutting with the slotter, the tongue length/groove depth is controlled by the pilot bearing or the fence, while the position of the cuts on the edge of the work is controlled by the bit-extension adjustment. All the cuts are made with the work flat on the tabletop or the router on the face of the board.

Start by cutting the groove. Rest the stock flat on the tabletop by the cutter, and raise or lower the cutter until its tip is centered on the stock’s edge. Adjust the fence for the desired depth of cut. Feed the stock across the tabletop, its edge tight against the fence, to make the cut. As with the straight bit, you can use a two-pass approach to center the groove. Make one pass with the face against the tabletop, the second with the back against the tabletop. The groove will be slightly wider than 1⁄4", most likely, but it’ll be centered. Then fit the tongue to

that groove. When you switch the setup for cutting the tongues, leave the fence setting alone. Lay your grooved sample beside the bit and lower it until the cutting tip aligns with the groove wall that’s closest to the tabletop. (You don’t want to trap the work.) Cut a test tongue and adjust the setup as necessary to fit the tongue to the grooves. Dedicated tongue-and-groove cutters: Most bit manufacturers sell individual bits or sets of bits designed specifically for cutting tongue-and-groove joints. Most give you two separate bits, one for cutting the grooves, the other for the tongue. The benefits are: • You shouldn’t have to “fit” the tongue to the groove. Out of the box, the cutters will produce the optimally fitted joint. Provided the bits have sufficient capacity to work stock more than 3⁄4" thick, and provided you mark a reference – and mind the marks as you work – having the groove and tongue offcenter shouldn’t be a problem. • Set up two tables, one for each bit, and you can mill stock in production mode. But unless you do a lot of tongueand-groove joinery these dedicated cutters aren’t a worthwhile investment in my opinion.

The tongue-and-groove joint requires preciseness of fit rather than preciseness of dimension. As with other setups, I eyeball the slot cutter elevation in relation to a centerline marked on a work sample. The groove is centered using the two-pass work sequence, and the exact groove width is only marginally relevant.

With a slot cutter, the work rests flat on the tabletop throughout the cut. Center the cut accurately in the usual way: Make passes referencing both faces. The second pass will probably widen the groove slightly, but it will ensure it is centered.

Always make the tongue-forming cuts with the cutter lowered to the table, rather than trapping the work between it and the table. As with the other tool setups, you use a grooved sample piece for the initial setting. (This router table has a topside adjuster.)

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JOINERY TIPS & TECHNIQUES. Copyright © 2012 by Popular Woodworking. Printed and bound in China. All rights reserved. No part of this book may be reproduced in any form or by any electronic or mechanical means including information storage and retrieval systems without permission in writing from the publisher, except by a reviewer, who may quote brief passages in a review. Published by Popular Woodworking Books, an imprint of F+W Media, Inc., 10151 Carver Rd. Blue Ash, Ohio, 45242. (800) 289-0963 First edition. Distributed in Canada by Fraser Direct 100 Armstrong Avenue Georgetown, Ontario L7G 5S4 Canada Distributed in the U.K. and Europe by F&W Media International, LTD Brunel House, Ford Close Newton Abbot TQ12 4PU, UK Tel: (+44) 1626 323200 Fax: (+44) 1626 323319 E-mail: enquiries@fwmedia.com Distributed in Australia by Capricorn Link P.O. Box 704 Windsor, NSW 2756 Australia Visit our website at www.popularwoodworking.com or our consumer website at www.shopwoodworking.com for more woodworking information projects. Other fine Popular Woodworking Books are available from your local bookstore or direct from the publisher.

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Acquisitions editor: David Thiel Designer: Karla Baker Production Coordinator: Mark Griffin

Read This Important Safety Notice To prevent accidents, keep safety in mind while you work. Use the safety guards installed on power equipment; they are for your protection. When working on power equipment, keep fingers away from saw blades, wear safety goggles to prevent injuries from flying wood chips and sawdust, wear hearing protection and consider installing a dust vacuum to reduce the amount of airborne sawdust in your woodshop. Don’t wear loose clothing, such as neckties or shirts with loose sleeves, or jewelry, such as rings, necklaces or bracelets, when working on power equipment. Tie back long hair to prevent it from getting caught in your equipment. People who are sensitive to certain chemicals should check the chemical content of any product before using it. Due to the variability of local conditions, construction materials, skill levels, etc., neither the author nor Popular Woodworking Books assumes any responsibility for any accidents, injuries, damages or other losses incurred resulting from the material presented in this book. The authors and editors who compiled this book have tried to make the contents as accurate and correct as possible. Plans, illustrations, photographs and text have been carefully checked. All instructions, plans and projects should be carefully read, studied and understood before beginning construction. Prices listed for supplies and equipment were current at the time of publication and are subject to change.

Metric Conversion Chart TO CONVERT

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MULTIPLY BY

Centimeters

2.54

Inches

0.4

Centimeters

30.5

Feet

0.03

Yards

Meters

0.9

Meters

Yards

1.1

Inches Centimeters Feet Centimeters

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WOODWORKING

Joinery Tips & Techniques

From Dados to Dovetails — It’s All Here! From the lowly butt joint to the vaunted dovetail, joinery makes a woodworking project stronger, attractive and durable. Learn how to make the most common woodworking joints using hand tools and power tools, with tips to speed and improve your work. Also included are plans for jigs to make your work easier and more precise, advice on building frame-and-panel doors and step-by-step instructions for lots of dovetails, including sliding dovetails. If you’re just starting out in woodworking, or if you’re looking for a way to just improve, we’ve got the joint for you!

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