Hard plastic / resin coating on carved foam

[pghfett]

Hello everyone,
I have a carved foam sculpture and I want to cast a hard coating over the foam. What should I seal the foam with first to so what ever I hard coat I use is not absorbed into the foam, and what are some hard coat options I can use. I'm familiar with epoxy and fiberglass mesh and some pour - a - plastic type materials.
please any suggetions would be appreciated. :confused:

[pghfett]

Anyone have any suggestions please? :confused:

[BMBourgoyne]

Depends on the type of foam and type of coating, as well as the properties you want in the final surface (thickness, detail ,durability, weathering, etc).
check out Smmoth-On's website, www.smooth-on.com
they have a spray-on plastic you might consider, and their technical support guys might be able to advise you on other materials for your particular application.

good luck,
Brad

[gmckib]

I have sculpted a couple of dinosaurs, both carved out of polystyrene foam. I covered both with fiberglass. Be sure to use epoxy resin though, not polyester resin (Bondo consumer products, for example). Polyester dissolves the foam.

The fiberglass coating is time consuming but gives a very durable finish that will stand up to outside conditions if coated.

I just finished a giant ant, also of foam, and just coated with several coats of, first shellac, then paint. It looks fine but of course is not very durable. A jab with a sharp object will puncture it. If I had it to do over I would coat with epoxy - no glass cloth, just the resin. I believe that would be tough enough for an indoor sculpture.

gmckib

[gmckib]

I meant to say in my latest post that you still have to coat with something after coating the foam with fiberglass. For the smaller dino I used Magic Sculpt - an epoxy putty. It's expensive and rather slow to mix and use but is very durable. You can use a pattern roller to emboss designs in it.

I am currently using something less expensive and easier to use than the epoxy coating. It is Dap spackling compound, rated for exterior use. It has yet to stand the test of time - still working on it. But I believe it will hold up fine after coating with paint and then exterior grade polyurethane varnish. It costs abouot $13/gal at Lowe's. It's heavy, which is a disadvantage. About 26% of the product is water, so it does get lighter after drying.

Gerald

[Ironlady]

i use mortar mix. just mix fiberglass (fibers...) into the mix. as long as you have a properly constructed armature it works great.

[csingmaster]

google hot wire foam. The hot wire web page has a hard shell mix that is easy to use. I have used it with success in the past.