Sculpting foam?

[DizzyStrmtroopr]

im a whiz with monster clay but im looking to do a chest plate and shield which id need a large surface to start with and shave down. what type of foam is recommended that I can buy locally and how would I lay clay over the top without getting little foam crumbs stuck in it when I tear down after molding?

 

[carluccidesign]

im a whiz with monster clay but im looking to do a chest plate and shield which id need a large surface to start with and shave down. what type of foam is recommended that I can buy locally and how would I lay clay over the top without getting little foam crumbs stuck in it when I tear down after molding?

Try using the blue or pink insulation foam. It can be carved and sanded nicely. As far as crumbs from it. You must seal your foam with shellac or skim coat it with plaster. Good luck

 

[blue2k]

Use any expanded foam you like (or even polystyrene). Just cover the foam in foil before you apply a layer of clay.

 

[DizzyStrmtroopr]

can it be had at lowes/hd? I saw someone had giant sheets of eps foam but not sure where to get these. I had thought about the cheap green floral foam but its messy and wouldn't know how to keep the bricks together

 

[blue2k]

Cavity wall insulation foam (spray) or thermal sheet material (like the pink builders foam). You can find both of these products at most chainstore diy places. The pieces of foam can be cemented together using spray foam, or a non solvent based glue.

 

[DizzyStrmtroopr]

alright so I found a 6 year old thread regarding the pink stuff but id imagine theres been some advances in techniques since then. my guess is if I can get the sculpt good enough I wont need to cover it with clay for the details, is plastidip the go-to sealant nowadays? guess ill try the krylon h20 stuff on a test block as well. I also know of the expanding foam, it turns into corn pops cereal looking stuff, is there a suggested brand or type I need to look for? thanks

 

[blue2k]

Any sealant will work fine as long as it doesn't react with the foam. Foil, varnish, plastidip, plaster, jesmonite etc etc. It all boils down to cost. Any spray foam will do, it is going between layers anyway, so how it looks when it expands isn't important. It will be confined between the layers.

 

[Leigh]

I sealed mine with a couple of coats of PVA glue (school glue). Try to pick up polyurethane foam, polystyrene will melt with some fillers. I pinned mine together with wooden kebab sticks & you can glue it with ca glue or PVA. Once its sealed you can get oil based clays to stick pretty well.

HTH

 

[DizzyStrmtroopr]

im getting the hang of this. for anyone with the same query, I sprayed like 4 whole cans of the Great Stuff foam. after 1 layer wait to cure about 2 hrs before piling on another layer, and I built it up to the size I needed but I find theres still large bubbles between layers after cutting the edges off with a hacksaw blade. I did find the blue sheets at lowes and I suspect home depot would have pink, but in any case ive only a motorcycle for transport so a can is less then $4 at walmart and easy to throw in my bag. looks like ill still have to use clay anyway.. thanks all

 

[Pippspriller]

I would use a medium density urethane foam panel. It is more expensive, but it has totally uniform micro bubble size and no voids. It is like a slightly less dense version of Renshape. Just sand it into shape.