Using spray foam to make armor, is it possible?

[Riceball]

Having finished watching Barbarians recently, I've gotten the itch to try to making my own Roman style muscle cuirass since the off the shelf ones suck and I'm poor and getting one custom made is out of the question since I'm poor. So, my idea is to use either a base of craft foam or some vinyl that I used to make a Greek linothorax ages ago and use expanding spray foam for the muscles. The idea would be to draw out the shapes on the base, maybe add some pieces of foam to give the spray foam something more to grab on to, then once the foam is dry, sand it down to shape. Does anyone know if this would work? Is spray foam shapeable/sandable when dried?

 

[division 6]

Won't work.
It will be full of bubbles (like inside a loaf of French Bread but worst) and you'd have to fill it all in with bondo or something.
Also if it's to thick there will be pockets inside that just stay as a liquid goo.

You would be better off using pink insulation foam.

 

[joberg]

I usually have decent spray-foam pieces with close-cell foam, not the one you can buy in a store. The trick, also, is to spray small amount everytime and to control/limiting the rising of the foam with a spray-bottle full of water.

 

[Riceball]

Won't work.
It will be full of bubbles (like inside a loaf of French Bread but worst) and you'd have to fill it all in with bondo or something.
Also if it's to thick there will be pockets inside that just stay as a liquid goo.

You would be better off using pink insulation foam.

Thanks for the advice, but I'm not too worried about air bubbles as long as they're not too long and numerous. As for pockets remaining gooy, I guess I would have to build it in layers and not spray it on all at once. Which, admittedly, would be tough for me since I'm not the most patient of people.

Pink insulation foam does sound like it might work better though. The main thing is that I don't want to have to do a lot of sculpting and I figured that spray foam in the general size and shape would allow me to just sand it to how I like.

 

[division 6]

Pink foam can be cut with a saw or knife, sanded and filed.
You should even be able to do at least a couple vac pulls off of it if you wanted.

The spray insulation foam would just be way to much work.

 

[PoopaPapaPalps]

I second what division 6 recommends. Get insulation foam at the hardware store, stack and glue the pieces together to make a base, and seal the foam with wood glue, elmers glue, mod podge, whatever you've got that cures and can can be sanded to get a good surface to pull forms from. Alternatively, you can do that method jut to make a base and then roll out a layer of clay to sit on top of it so you can sculpt your armor, then mold and cast that.