Builders' Forum Archives
installing shear clamps
Posted by Dave Houser on Dec 18, 2004
Shear clamps are necessary if you want a cambered (radiused) deck. It is just too hard to bend a deck and hold it place with stitch wires while gluing the seams. Shear clamps can also be used with faceted decks to avoid the taping crawl when joining the deck to the hull.
The shear clamps start out 3/4 inch square in cross section. It is wise to radius the corner your knees will bang on and sand the two finished sides before epoxing them to the top of the side panels. The shear clamp must be glued onto the inside top of the side panels with about 3/8 inch sticking above the top edge at mid panel. This allows you to plane a rolling bevel into the top of the shear clamp without planing away any of the side panel. The surface of the rolling will provide a 3/4 inch wide gluing surface to attach the curved deck. At the bow and stern the deck is almost flat so the rolling bevel barely extends above the side panels and the clamps should barely extend above the sides there.
After the deck is attached then softening the corner of the shear is possible even planing into clamp as I have done. Of course the epoxy/glass of the deck wraps an inch onto the sides covering the exposed shear clamp and plywood plys.
The shear clamps are often used to sink the wood screws into to attach the deck rigging loops, hatch straps and the seat back band.
In Response to: Re: planing shear clamps by Gayle Rhodes on Dec 17, 2004