Bob,



I agree about the resins as they can be pretty noxious, but according to the MSDS on the stuff I've used [which isn't that expensive], only a respirator with paint/solvent cartridges is what is required. The two part urethane foam has a slight odor but is by no means noxious enough to require the use of a respirator. The products I'm talking about specifically are made by Eager Plastics [www.eagerplastics.com]and I'm referring to the EP 4202 rigid casting foam [$37 for a two quart kit - $78 for 1 gallon which can yield an 8 foot by 8 foot block of foam], and the EP 4117 General Purpose laminating resin [about $37 for 1 gallon kit]. In response to the other mention of the Zoopoxy products, we've used at least one of their products to make climbing vines for our large exhibits at the zoo. I has a definite stink to it but again, not a highly toxic product. Also, the Zoopoxy products have the advantage of being completely non-toxic and inert in their cured stage. The Zoopoxy stuff is more expensive than the Eager Plastics stuff. Ultimately I think provided you do research and find good products that aren't overly toxic that urethane foams and fiberglass resins can yield excellent results without the weight issues with concrete. Of course if we're talking about working with concrete as being safe I'd have to say that in many respects even using it in a well ventilated area it's still potentially as dangerous or more dangerous than the chemicals previously mentioned and this primarily because the potential for respiratory problems associated with fine dust particles, among them a type lung ailment refered to as silicosis which is caused by breathing in fine particulates. Again, if you're going to be working with concrete you should still be at least wearing a dust mask and to be truly safe you should be using a cartridge respirator with dust filters.
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Matt Campbell



Big animals, little animals, plants - right down to the sea itself. We need them, not just for their own sake, but because all this has to be here for everybody forever. Only one thing is certain: if we are to preserve our environment and save this priceless wildlife we need much, much more knowledge.

Harry Butler from 'In the Wild With Harry Butler' 1977

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