I need a putty for molding a prototype of something. I’l like to have >5, ideally many more, minutes to work with it before it sets. I see the Green Stuff epoxy and that could work I suppose. Are there any that set to a more rubbery consistency? Any options appreciated.
You might want to check out:
Type “flexane” in the search box.
I cast rubber drive rollers using flexane. They have putty and liquid forms. I’ve only used the 94 liquid. The material is very tough and doesn’t crack or otherwise seem to deteriorate with age.
It forms a very hard rubber, about like a fan belt. It’s black.
When I’m sculpting a figure (my skills are so crude that I hesitate to dignify the process by referring to it as “sculpting”, but there you are), I always use Milliput, a two-part epoxy putty available at finer hobby stores. But it hardens rock-hard.
If you want something flexible, the Bare-Metal Foil company (http://www.bare-metal.com/) offers rubber compounds which consist of two putty-like components one kneads together. But I don’t know how sculptable the result is; I think its primary use is to press onto a male master to make a flexible female mold to pour resin into.
How about that wax that the lost-wax people use? Or Plasticene?
One thing I’ve used for mock-ups that has worked well for me is -seriously- Crayola Model Magic. It comes in several different sizes, and starts out as a slightly moist, puttyish material that dries to a flexible but fairly tough foamy stuff. It can be painted as well. I’ve taken a liking to it because it’s light and won’t break if dropped.
There’s also my latest obsession, polymer clay. The only disadvantage is that you have to bake it to set it (a regular oven works fine). The Sculpey brand polymer clay also has a bendable polymer clay that has quite a bit of elasticity. It makes pretty good molds because of this.