I have seen big black thin pieces of rubber before, maybe laying around at a construction site. I am not sure what it is used for, but it would be ideal to line the inside of a wooden box to make a watertight tub. What is this rubber, or can you recommend something else?
One uses a spring and the other uses hydraulic pressure.
The type of two-part resin most commonly used for making fiberglass is polyester resin. Epoxy resin isn't as good, I'm pretty sure, at least because the polyester type stays tacky on the open side, so it needs to have something on top of it (another layer of resin-soaked fiberglass). What's created is actually a glass-reinforced plastic. There are various places to buy polyester resin, as mentioned, but you might be best to go to a boat store or automotive store where someone can tell you the differences between the brands of it, etc. Diane B.
