STAINLESS STEEL
The Art of Stainless Steel By Charles Husick
A
lthough you may not have thought much about it, the stainless steel bow pulpit or railings on your boat may be a piece of fine nautical sculpture. Your appreciation of the artistry and value of this sculpture may rise as mine did when you damage that too-often overlooked piece of stainless steel. The bow pulpit on my 46-foot Irwin ketch survived 23plus years with only minor, easily repaired damage (caused by another boat). However, I recently tested the integrity of the pulpit by running it into a stout piling while docking at a nearby yacht club. Unfortunately, the kinetic energy of 34,000 pounds of boat was more than sufficient to override the minimal speed of the impact. The thoroughly crushed upper rail and overall distortion of the entire pulpit severely bruised my pride and would require the acquisition of a new piece of sculpture. Since we were about to invest in a new bow pulpit, we decided to learn how this piece of nautical sculpture would be created. After investigating the available choices, we elected to visit what turned out to be a virtual artist’s atelier, Embree Welding, in St. Petersburg, FL. At first glance, Doug Embree’s facility appeared to be a typical structural welding shop. A mixture of machine tools, saws, shears, a brake, well-used Bridgeport milling machines, a number of hand and hydraulic-powered tubing bending devices and an assortment of electric arc welding outfits, each accompanied by a tall cylinder of argon gas. We noticed that the raw
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September 2006
SOUTHWINDS
material storage racks contained only stainless steel. The only common steel we saw was outside, at the back of the shop. Our new sculpture would be constructed using 1-inch o.d. type 304 stainless tubing purchased from the mill polished to grade #10, the highest available. As we know from past experience, stainless steel is actually “stain” or rustresistant and does not offer total immunity to oxidation. Doug explained that he excludes all common steel from the primary work area to avoid contamination of stainless welds with particles of ferrous material that could later rust. He is also very careful to ensure that no ferrous material comes in contact with the work during the extensive polishing work needed to smooth the welds. We have seen and admired railings on powerboats that extend for more than 70 feet, with no sign of a joint anywhere. Since the longest lengths of tubing are far shorter (about 30 feet in length) and since working with a 70-foot length would pose problems in the shop, it is obvious that these seemingly continuous rails must contain virtually invisible splices. Embree makes the splice by first cutting the ends of the tubing to be joined at a precise 90-degree angle. A foot long length of 7/8-inch tubing that will just fit into the inside of the 1-inch rail is prepared by cutting two narrow slits for half the length of the tube. Two additional slits at 90 degrees to the first slits are then cut beginning from the opposite end. After cleaning, the slit tubing is forced into the ends of the rail to provide mechanical strength across the joint and to ensure that the joined tube will be in precise alignment. A very carefully done circumferential weld joins the three pieces of tubing into a continuous length, after which the polishing process eliminates all visible evidence of the presence of the joint. The Bridgeport milling machine is used to prepare the ends of the lengths of tubing used to support horizontal rails. The required cuts can be complex since the support rail may intersect the top rail at other than a 90-7degree angle. To assure a high quality finished product the machining must be quite accurate, filling a large gap when welding won’t do. The material content of stainless steel (steel that stains less) creates special requirements if the corrosion resistance www.southwindsmagazine.com