hi, i have a js550 project ive been working on, been using polyester on most things, pump cavity, rockered nose, nose peice. an old fiberglassing expert told me its all the same thing, that polyester is weaker but lighter than epoxy, but i should have no problems with it sticking. (hes had alot of fiberglassing fumes get into his head though lol) and others tell me the polyester will peel off in time. the 550 hull is made of like fiberglass and plastic mixed, SMC (sheet molded compound). ive got epoxy resin and cab o sil on the way too, but just what sticks best? ik vinyl ester is supposed to stick better, but epoxy is the strongest structurally. so give me some answers!!!!! only comment if you have a real answer lol not an opinion! i need some expert advise, everybody seems to have something diffrent to say.