Something New: Casting Idea - What material

Ok, so i have been creating casts of my fixed/redesigned custom MR.

Im thinking about doing something new and different. Evan helped me originally with my mold making info, as well as FP. I dont want to burdon them at this trying time, so I figured I would openly ask opinions on this.

1. What 'rubber' material would I use for making stunt rubber props. Saber hilts, guns, knees or even rubber 'muscle' plates for a suit.

2. And this is my new idea. I have shellshock, which is a hardening plastic thin coat resin that makes a nice barrior/coating type of finish. I have thought about using 'featherlite' as a second layer. It is an ultra lite foam/plastic. It floats in water. Its similar to the finishng lure foam/plastic you see.

This would make for a extremely light, durable helmet. So. Any input?

Im thinking about geting some either foam or featherlite and making some 'thick walled casts, that I can sculpt into as well as onto. And for some reason, this jus tseened like a good idea:)

PLS let me know what you think, and if you have any info on rubber for casting id love to hear it.

I think smoothcast 1520 is similar to hyperfirm rubber, but don't quote me on that one... I read a long thread about it, but I can't remember where...rpf or TDH. Other than that, I've never used rubber for casting.

I've tried shell shock before. It made a nice casting, but was very brittle.

I figured shellshock was brittle, but what about a foam underneith it? I was thinking shells hock, then expandable, to make vac u form pieces:)

But it seems liek the featherlite under shellshock might be pretty sweet. it says its the same density of 'fishing lures' and it 'floats'. *shrug*

I also heard that Smoothcast 1520 was similar to hyperfirm rubber.