Im going to mold a mannikin that I sculpted from clay. Its about the size of a rabbit. Im going to make a permanent fiberglass mold so that I can cast and recast my own mannikins from it. What can I use as a dam, so that I can have nice flanges to work with and bolt when I pour my foam? How thick should I make my fiberglass mold(layers wise) so that it can stand up to the pressure of the foam? And how do I prepare the clay mannikin up to the point where I apply the gelcoat?
Thanks, Jake
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You can use aluminum flashing for your dam,by slitting the clay and inserting or you can make clay dams app. 2"x1/4" or so,press them in place and insert long pins down through the clay dams into the clay model.After the dam is in place,spray the clay model and dam with fast drying Krylon spray paint-any color that will allow you to see your PVA well as you apply it.It helps to use 1 or 2 layers of thinner mat,like 3/4 oz.,then several layers of 1 1/2 oz..I'd say 2 layers of 3/4 oz. and 4 or more of 1 1/2 oz..It needs to be about 1/8" thick when finished.After removing the dam and before doing your second side grind some divots in the first flange with a dremel and grinding stone.Then Krylon, 2 or 3 coats of PVA,then jel coat and so on.