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sure it can
By:Paul G. Jacobson
Date: 3/5/2002, 9:18 pm

: I am building some S&G boats and I am wondering if I can use a different type
: of material for the shear clamps and cowling. I have used mahogany in the
: past but it seems to be hard to find and expensive. Has anyone used cedar
: of bechie or anything else? Thanks

I never heard of cedar of bechie, but if that is available, go for it.

otherwise, there are a few points to consider. The sheer clamp is mostly hidden, and serves to back up the nails or screws that attach the deck to the hull. Practically any wood that holds a nail can be used. Common pine, spruce or fir from amy lumberyard should serve just as well. Try to avoid pieces with large knots as knots are difficult to nail into. If your wood does indeed have knots, well, mark their locations so you can avoid nailing into them.

The coaming has a few special comcerns. It must be strong enough to support the weight of the paddler doing an entry, hard enough to resist denting from occasional blows by the paddle, and finally, being the centerpoint of your boat, it would be nice if the thing looked pretty.

For this, though, you can find easy solutions. Practically any wood, from ash to zebrawood, can be made to work by covering it with a few layers of glass cloth and epoxy resin. The fiberglass will both enhance the strength and the ding resistance of the wood. If you use ironwood you might not need any reinforcement. If you use balsa you might need 3 or 4 layers of glass cloth and resin. You don't even need to use solid lumber. Some people build up their coaming from pieces of plywood, stacked like layers of cake. That has a distinctive layered look, as you can see the edges of each row of veneer that went into making the plywood. The cross section of this type of construction tends to be a bit larger than what you might get from using a hardwood, but that makes them strong and stiff.

That brings up another point. When replacing a hardwood with a softer or weaker wood, you should probably increase the size of the part so it will be as strong as the piece you are replacing.

If oak or poplar are available, try some. Since you are making several kayaks, why not use a different material for each one?

Hope this helps.

PGJ

Messages In This Thread

Material: Can Shear Clamp something other than mahogany?
Paul Pinder -- 3/5/2002, 6:37 pm
Re: Material: Can Shear Clamp something other than
Rob P -- 3/7/2002, 12:25 pm
Re: Material: Can Shear Clamp something other than
Chip Sandresky -- 3/6/2002, 1:16 pm
Re: Material: Can Shear Clamp something other than
Bobby Curtis -- 3/6/2002, 9:15 am
sure it can
Paul G. Jacobson -- 3/5/2002, 9:18 pm