I'm buying a set of Tie Pilot armor made out of styrene. I was thinking of putting a layer of fiberglass inside the armor to strengthen it. My question is, will the fiberglass stick to the styrene or ruin it? Any help would be great.
It should stick just fine as long as you rough up the styrene a little with some heavy steel wool or light sand paper. The only issue you might have is the heat from the fiberglass setting warping the shape of the styrene, to help this issue wrap the face side of the stryrene with a wet rag.
Personally I like the flex of the styrene or ABS as it provides a little give when wearing the outfit, unless of course the person used a real light gauge plastic.