Funny,I was going to mention the sheetrock compound, but deleted it. I was afraid that the paint might pull it out in flakes, chips when a boat is released, as they can stick pretty good. My second reservation was that is does not flex, so the mold would have to be perfectly rigid, which can be tough to do, especially when it comes to popping a boat (or dropping the mold). It might not stick to bare masonite very well, but one could sand it to rough it up. Even with those reservations I think it realy has place in boatbuilding, especially if one was constructing a plug. If i was doing the mold myself I would be tempted to use it a little.

If you do use it, the dry mix kind is far stronger than the redimix. The drymix comes with working times, just like epoxy. It sands soooo much easier than the premix, is lightweight and it can be applied very thick 1"+ without cracking and very little to no shrinking. All in sharp contrast to the premix mud in my experience. Just remember to clean up before it sets!

: I agree w/ both david and bart: the mold needs to be supported - by female
: forms.

: The joints need to be faired. What about using dry wall compound? cheap as
: hell and sands well. You should use the drywall 'tape' that is ACTUALLY
: f/g so that the jts are slightly reinforced. Use part of a plastic bottle
: as the scraper to make a constant radius fillet.

: the shiny surface needs to be sealed 1st to use a release. Probably any paint
: would work. And obviously paint the jts.

: For the foot bumps, cut ovals in the forms, and say drape burlap sacking (or
: any cloth - towel?) into the holes wetted out w/ major glue. Let set up
: and cover w/ torn newspaper dipped into white glue like paper mache. Sand
: flush and it may work. Maybe tape a blown up balloon very slightly
: protruding into the hole to set the burlap shape first. Use the drywall
: compound on irregularities.

: And when you'r done, you could actually stitch it together w/ some glass
: strands pulled from the 10oz cloth. Leave em in and then do the seams and
: they'll disappear.

: -mick