BOATBUILDER’S NOTES

Boatbuilder’s Notes By Robin Gates

Chisel knife

The Hultafors square-ended chisel knife is rather more knife than chisel, because the edge is bevelled on both sides, but it’s nonetheless a useful hybrid of both kinds of tool worth keeping to hand in a cockpit locker or attached to your belt by its plastic sheath. The carbon steel blade is 1 70mm long, a sturdy 3mm thick and ground flat on one edge – well up to driving with a hammer, as you might do when splitting kindling for a barbecue. The meaty handle likewise withstands a heavy blow so you might use this tool for rough tasks where you’d hesitate to deploy a more valued chisel, yet it’s also precise enough for more critical work like cutting a hinge mortise. The fact of the handle being longer than the blade assists with accurate positioning, much like a butt chisel. Handy for cutting wood, plastic or rope, and excellent value at around £7.

1: Cutting three-strand line with the knife edge 2: Hinge mortise chopped out with the square chisel end

2

L-R: Wing, Moore & Wright and Lancashire dividers

ROBIN GATES

Step out with dividers

Dividers are invaluable for transferring measurements without recourse to a ruler. The forged iron type used by a 19th-century shipwright was securely locked by a screw tightening on a quadrant extending from one leg, and the tool is also sturdy enough to scribe an arc with sufficient clarity to guide the saw. The lighter Lancashire pattern spring dividers adjusted by a wing nut acting against a bow spring are prone to twist if used for scribing, but are favoured by joiners for the more delicate work of stepping out marks for dovetails.

More rigid and precise than the old Lancashire sort are the spring dividers used by toolmakers, such as these made by Moore & Wright around 1950. Legs pivoting on a hardened steel fulcrum are set by a sophisticated ‘quicknut’ with split collet, permitting rapid readjustment between wide settings. Similar M&W-branded dividers are available from Workshop Heaven in Banbury, priced at £21.50.

CK 4oz pin hammer No 4203 (left) and Warrington 8oz hammer (right)

CK pin hammer

ROBIN GATES

It’s far from being the cheapest pin hammer on the market but I’ve found the 4oz No4203 made by CK (which stands for Carl Kämmerling, who founded the company in 1904) to be a solid investment. This old example has an ash handle, whereas today’s is fitted with the similarly durable and shock-absorbing hickory, but the shapely swellings which fit the hand so well remain unchanged, as does the secure wedging to the dropforged head of carbon steel. The hammer is well balanced, with the weight of the head concentrated over a small area that’s ideal for driving small nails and pins, while the flattened cross pein (or peen) is designed for getting them started while gripped betwixt finger and thumb. Pictured alongside the joiner’s standard 8oz Warrington hammer for comparison, the CK pin hammer has an RRP of £18.22 but may be less at cktoolssuperstore.co.uk.

Boatbuilder’s Notes Traditional Tool

By Robin Gates

CARD SCRAPERS

The finest finishing tool known to woodwork is a flat piece of steel: the card scraper. On hardwoods, and especially those with confused or curly grain, it takes over where the plane leaves off, and may be shaped to work all manner of curved surfaces.

Tempered high-carbon steel from a hand saw is of ideal hardness and thickness. It’s hard enough to hold a durable edge but not too hard to file by hand, while also being sufficiently flexible that you can bow the edge as you push or pull the scraper along. The cutting edge is unique, neither bevelled like a plane or chisel, nor toothed like a saw, but shaped into a continuous hook or burr.

Preparing a new hook requires that the remnants of the old one first be removed by filing. The edge is next made perpendicular to the faces by rubbing on an oil stone, and then a burnisher (which can be the rounded back of a gouge) is pushed along at an angle gradually increasing to about 85 degrees, thereby spreading the steel to create the tiny new hook which is detected using a fingernail.

The most generally useful card scraper is rectangular or with moderately convex long edges, the sides being left without a hook so that, combining top and bottom, there are a total of four cutting edges. The tool is most commonly pushed using both hands with fingers at the sides and thumbs pushing in the middle, to generate the bow, also leaning forward at an angle just sufficient to bite, although a scraper may also be drawn towards the worker, and even used with one hand. The corners of a rectangular scraper may be rounded with a file to avoid risk of them digging in.

The scraper works with, against or across the grain without causing tear-out, and is essential for smoothing thin veneers and the alternating grains of inlays. If sharp, it generates fluffy shavings and leaves a glass-smooth surface in its wake. Store scrapers in a wallet between uses to avoid damaging their vulnerable edges.

Over the last five years these Sheffield-made scrapers (branded Garlick or Pax) have proved extremely useful, and at around £12 for the set of four they are also excellent value.

Clockwise from above: Smoothing a hollow with the goose-neck scraper; Keep scrapers in a wallet to protect their edges; Round the corners of a rectangular scraper with a file

NEXT MONTH: Coe’s wrench

ROBIN GATES