Simon,
You have given us an excellent overview the mold building process.
You can hardly be going through all these difficult steps just to make a single hull. Are you and your friends engaged in a commercial enterprize?
Charlie

: I am currently working on a similar project with a couple of guys. We made
: our male plug from foam and plaster, which is a tremendous amount of work.
: We continuously add plaster, fair, add plaster, fair and so on. Our plug
: is almost finished now, and we expect to be laying up our 2 part female
: mold in a few weeks. Our layup is going to consist of wax, wax, PVA, PVA,
: Gelcoat, Gelcoat, Fiberglass mat, 6oz glass, 6 oz glass, 18 oz roving, 1/2
: inch plywood frames. I'm linking a pic of our plug in its current state.