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.

: I have a vintage 1960's fiberglass Giak (cross between a canoe and a kayak).
: But it is showing its age and is quite heavy (100#). Some of this is due
: to having been repaired several times (my dad cut it in half to bring on
: the plane how from Canada). It is a two piece construction (top and bottom
: hulls) screwed together.

: I was thinking of mold and then lining it with kevlar and glass. Any
: suggestions on a better way? I plan to make two more for my brothers. Or
: anyone know someone who would do this for me?