Hi here is a site that can help.
www.fibreglast.com
Also I am in the process of altering my running boards. I like the part about the spray foam. will this foam stick and frim up pretty fast? I have release agent, but I'm told waxing the mating area and then apply the release, will help the parts to come right off. Where can I buy this foam? I went to Micheal hobby shop and bought some hard foam the kind they use in flower decoration. But not the spray foam, it seems much easier with the spray foam, I will give it a try.