JEM Watercraft

it wont have the same effect as building from epoxy to begin with ron. And I know you directed this to jem but... Epoxy will stick to poly, but poly will not stick to epoxy.

You can skim with epoxy on your boat if you like, but it wont have any genuine effect unless your just trying to put a mix of graphite and epoxy on the bottom.

You could apply a layer if you scuffed up the poly surface. But one layer of epoxy over a polyester shell won't add much benefit.