How to built/construct a hollow rock replica from fiberglass materials? need to know what to buy fiberglass materials and chemicals to replicate...
need to know what to buy fiberglass materials and chemicals to replicate a rock so it may be lighter and movable
Answers: You want to Buy
a.) fiberglass cloth (fiberglass mat might work if its a big, simple rock)
b.) polyester resin
OR
A.) Fiberglass cloth (or mat)
B.) Epoxy Resin
You can bring back polyester resin and fiberglass at a most bigger hardware stores. Epoxy resin you will have to find at a boat building supplies store or online. They craft some eco-friendly epoxies that are used in zoos to fashion fake rocks and stuff. Link below. Call these guys up, they will minister to you with what you inevitability.
Polyester is much cheaper, but is also pretty nasty to use (a respirator is strongly suggested). The same cloth/mat can be used for both.
If you want this rock to be complete (so it have a bottom as well as a top) later you might want to use the fiberglass to cover a Styrofoam core. Otherwise, use a real rock (preferably a smooth one) to craft a mold. Cover it with mold release, apply the cup and resin, pop the rock out, and there you own it. Then use the mold release again in the mold itself, and apply more fiberglass and resin the the inside, and pop that out. Sand it down as needed.
We built a 'pile' of rocks out of article mache years ago for stage props using chicken wire. We like them so much we saved them for adjectives productions. They started to take up too much room inside so we give them a coating of resin. They have be outside now for three years and necessitate the occasional patch here and there but look more and more believable as they age. RScott