I'll raise you: Cheap plywood works great if covered with cheap polyester
resin
and cheap matting. The matt/polyester bonds to ply better than
cloth/epoxy. One
can cover the matt with a layer of poly and cloth and *that* will bond to
the
matt!!! This last step isn't really needed, as the poly/matt protects just
fine.

word of warning - poly is (slightly) water permeable (significantly more so
than epoxy). Dad's boat was built using poly and is rotting under the poly
patches (interestingly, it isn't rotting where there has been nothing but
varnish over the top). Vinylester is a product possibly worth looking into,
I may have misunderstood something, but it'd sit between polyester and epoxy
with 95% of the latter's (gluing?) strength but 50% of the cost. Just a
thought.

Al