Boatbuilding Tips and Tricks
MONDAY, JULY 21, 2008
Fasteners for Boat Building
Screws? Nails? Bronze? Stainless? The array of possible fasteners for home built boats can be confusing, so I thought I'd offer a few guidelines on what may be the best for you. First, you need to know that modern boat designs don't rely nearly as much on fasteners as do their older ancestors. Nearly all home built boats made these days rely on adhesives for joint strength. Epoxy is the most popular with the new polyurethane "Gorilla Glue" type a close second. These adhesives will not fail if properly applied - the wood will break before the joint will give way. They'll even fill gaps that more traditional "glues" would never stand for. This means that when you use epoxy, all the fasteners really do is hold the joint in-place until the epoxy cures. After the epoxy sets up you could theoretically remove the fastener and not affect the joint strength.
Building an old mahogany boat with screws was quite a chore in the olden days. The screw holes had to be pre-drilled, then the screw run in with an old fashioned screwdriver, or perhaps a manual Yankee driver. It was a whole lot of work! New trends in fasteners have come about after the invention of lightweight cordless power drill and screwdriver tools, so it makes it a lot easier to install fasteners. My recommendation is to use what are called "deck screws." These are thin screws that can be screwed into place using a cordless drill without drilling a starter hole. This has revolutionized home wooden boat building world. Like drywall screws have replaced nailing, so have deck screws replaces boat nails. They're easy.
Next materials: It used to be that stainless steel was very expensive, but with most of the fasteners coming from offshore, stainless just isn't that expensive any more and for most trailerable boats, stainless makes an ideal fastener. It doesn't corrode normally with a boat that is kept out of the water even when used in seawater. I can hear the comments from readers now, "but what about everything I read that it corrodes when in seawater and embedded under a sealed surface..." Yes, OK, it can corrode under certain circumstances, but in my opinion, these are few and far between, and see paragraph 1 above - If it does corrode so what?
For a boat that truly is kept in a slip in the ocean, silicon bronze is probably a good idea. It's the finest of all boat building fasteners. They don't come in deck screw shapes, so you'll have to pre-drill starter holes, but you'll be able to drive them in with a cordless drill if you purchase Phillips head screws. You'll probably find silicon bronze ring type boat nails the easiest way to fasten the plywood planking to the framing on a ply on frame boat using bronze fasteners. The thought of drilling all of those starter holes in a ply covered boat would be a daunting task.