well im planning on making marine costumes for my friends, but i dont want to have to make 3 sets, and figured i could use the pep helmet as a kind of mold. i was planing on taking the carboard versoin of the helmet i have, making it waterproof, cutting it in half, then using either muslin cloth, and a wheat/glue paste, or plaster, but i dont know which one to pick. and suggestions? and i would use wither muslin cloth or plaster to strengthen the outside of my MC armor, with a laquer or varnish finish. again which one should i use (preferably which is less toxic) i cant use fiberglass, or resin, because my parents wont let me : ( any suggestions or answers will be very well apreciated!