Smooth-On sells Polytek74-30?Is that a pretty "firm/hard" urethane rubber?
Yes, 74-30 is specifically made to be a mold making rubber and is pretty tough stuff. It's great if you'd like to have the option to cut the mold open instead of making two halves because it's a very clear amber color. You can see very clearly right through it even if it's thick and that helps with both the mold making and casting. Best of all, 74-30 is one of the more affordable mold rubbers out there.
I am going to use Ecoflex 00-10 for the puppets. I am just learning all of this stuff, stop motion included, over the last few months. I had originally been planning to use plaster mould to cast silicone but when the guy at FibreTek, where I got the supplies, suggested the vytaflex for the mould. If it DOES work it will hopefully allow for tons of casts before it starts to deteriorate. It is pretty rough looking but I learned a ton of stuff doing this test mould
So far the shore hardness of 50 that the urethane has seems to be firm enough. I would love to use silicone moulds. It looks like silicone is the only thing that sticks to silicone. Does that mean horrible mess even if the contrast in hardness between cast and mould is adequate using silicone mould and silicone cast?ha ha
TEDCO Studios said:
"I would love to use silicone moulds."
Use urethane rubber instead. Polytek makes as rubber called Poly 74-30 that's perfect for making rubber molds you can cast platinum cure silicone out of and it works great.
Thanks very much Ron,
I will make sure to try out a test mould with Polytek 74-30 before choosing between the two. The Vytaflex 50 seems definitely stiff enough to do the trick. Any imperfections in the mould I am sure are human error;) There is a picture of the mould that I posted recently
I learned to make sure next time to use a flat sided mould, to make a cleaner transition between halves and to make nice clean keys. I pushed six main ones and a couple of smaller ones just to see the varying results and learned my lesson.
Thanks again and sorry guys for having strayed the conversation from the topic question about painting.