: I'm getting ready to start my first stripper - a Guillemot. I'm curious about
: what to use for the forms. I've seen that 1/2 inch plywood is fine. I have
: some around, but it's not flat, it's bowed. Most of the 1/2 inch plywood
: pieces I've bought have been bowed somewhat. Will this affect my boat's
: fairness? Would there be any problems with using 3/4 inch plywood instead?
: I don't mind the added expense if it's going to make a better boat.

That bowing usually comes from improper stacking. Plywood should be stacked standing on edge ( side ) and that won't happen.

Sometimes you can lay the plywood down on a damp surface, ( grass or cement ) with the bow up ^ and it may settle down when moisture gets to the tight side and the outside gets some sun.

I always like to use 3/4" plywood. Just more solid, and as Roger mentioned, heavier. But, you can remedy that by using another support under the beam.

Rehd