I have made several cowls by sanding a plug out of styrofoam about 1/4" longer than what I needed, covering with 2 layers light cloth w/ thinned epoxy, let dry a few days then melt out foam w/ dope thinner. made one for a 1/2 a cap, and an old out of production beercat bipe. used handi- wipes for beercat and a few others! it works well.