I‘m going to be building a costume for a convention in the summer, and the plan at the moment is to use pink insulation foam sheets for the body of the costume, and cover it with fiberglass (to give it a hard shell, as well as something I can easily paint over).(1) Can fiberglass adhere to the foam?(2) How smooth does fiberglass lay down?(3) . how do you work with fiberglass?
Yes it can adhere to the foam when you apply it in thin layers. Fiberglass consists of microscopic glass particles which when one is exposed to can cause problem to the respiratory systems and fatality too. So do ensure you wear the necessary safety equipments while working with it
If you mean pink fibreglass wall insulation, that's crazy and will itch like hell. If you mean styrofoam, polyester resin will dissolve it unless you prime it with size or plaster. Other plastic foam may be OK. Ask the store, or test a sample. Most commercial fibreglass things (like boats) are made in a waxed mould, starting with a coloured gelcoat then building up layers of glass cloth and mat. That's what makes them smooth and shiny (a lot of work making the mould, but you only have to do it once). Home-made things can start at the inside, like with the foam, and build up layers on the outside. But it's rough, so you have to finish with a fine mat and then add filler and sand it smooth. It's not a completely crazy idea - fibreglass is strong and waterproof and can be made into weird shapes. Motorcycle helmets etc. are often made of fibreglass (in a mould, then with styrofoam fitted inside afterwards). But you can end up with fine glass particles if you aren't careful - though you can paint a couple of extra layers of resin after sanding, and paint all cut edges. There's lots of books and probably articles online about working with it - mixing resin, curing, laying up mat, stippling etc. etc.
You're wanting to work with dangerous stuff. Fiberglass is a major irritant, it can blind you and stick in your skin like a million little needles, unless you're prepared to work with a respirator, goggles, and a full paint suit, forget it, you'll kill yourself.
