Hand Tools Archive

Subject:
Re: What I don't understand (power tool content)

TomD
There are different ways of doing strippers, well beyond what the strippre canoe type dudes do, and different methods work better in different situations. The four disadvantages to cove and bead (not all overcome by this method) are: 1) special tooling and even tools for some folks' 2) extra step in preparing the strips (this is obviously worse); 3) considerable loss of material width, and sometimes thickness; 4) This is the one he mentions. Basically you get less tight joints. I'm pretty savvy about wood; how boats are supposed to look; and the methods that create the look. Yet I was fooled looking at one of Ted Moore's canoes that had such perfect execution I thought he had come up with a way to mold a single sheet of plywood into the shape of the hull, the gradations in the wood were so imperceptibly perfect it looked like one piece. And I knew that folding a piece of wood that way was impossible...

With bead and cove the joints are not tight just because you clamp them, because the feather of the edge of the cove is not pressed down hard, the best you can do is tighten the strips, but they are not in the same axis. Sometimes they will flair out on the convex side and not have contact, or the inside of the feather will buckle on the inside of the bead edge. The end result can be some degree of imperfection in the joint that when planed and sanded becomes a wobbly line, or an area in need of filler.

For beads and coves to work perfectly, one would need to vary their nesting radii for given degrees of articulation, or the thickness of the materials, but they do not end up being prepared that way.

In my case, I am more interested in functionality as far as my contribution to optimizing strip building is concerned. Depending on the engineering, and it can vary with adjacent strips, the wood "core" can be an important contributor to longitudinal structural fiber. It is not always simply separating the skins of the structural fabric and matrix. As an example, if you look at the "football" on the bottom of a canoe or kayak, as pretty as it may be it is not aligned with the loads. It can be preferable, particularly on a spar or beam, but even on hulls, if the strips taper, to keep the wood fiber alignment and it's fabric component in the most efficient orientation (running parallel to the waterline, and the central plane of the boat). There are a number of ways of achieving that, but particularly on bright finished boats this could be a handy accessory.

As far as guttering the glue in coves, that is not necessary with clean butts as they will press out almost all the glue, and they do not need an excess of glue to fill gaps. We also have a far better selection of glues that work well for strip planking today, right out of squeeze bottles. When I started in this deal in the 70s, most builders were using epoxy for the inter-strip glue bond, but that turned out not to be necessary, at least for the smaller boats.

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