Post #464893 by Unkl Ian on Fri, Jun 26, 2009 6:55 PM

"Sulfur free" Plasticene is easy to work,
Plastilena makes Sulfur free Plasticene in different hardnesses.

Silicone Rubber doesn't want to cure properly, if you use the regular
Plasticene. The Sulfur creates some sort of chemical Voodoo.
So you need the Sulfur free kind.

That's the deal with Smooth-On products,
I'm guessing similar products are the same way.