Making 2 part Silicone molds troubles......

[delamaize]

ok, I'm going to pull my hair out.
I just destroyed another batch of silicone rubber, and a good start with the first part, because when I went to pour the 2nd part, the damn thing stuck to the first part, and I ended up with a block-o-silicone incased GHQ Abrams.  I have been using this German mold release between the 2 parts, and on the tank parts. It seems to work to keep the silicone from sticking to the Tank parts, but I can't seem to get it to work between the 2 diffrent pours of silicone.

What do I need to be using between the 2 pours to keep them from freakin' sticking to each other, I got a lot of tanks and some flat cars to cast, and I'm ready to scream!

[JoeD]

Easy,

I used to do a lot of sculps for Disney and Warner Bro's merchandise and had the opportunity to do a lot of multi part castings.  You need a barrier between the two parts and it can be as simple as some brushed on Crisco or as elaborate as spraying on Vaseline thinned with Acetone through an airbrush.   With the Crisco or other veg based cooking fats you can heat them up a bit and brush them on the RTV with a wide soft brush... and up to the master(don't get any on the tank as you might obscure detail.) .  Then you can give everything a quick spray of mold release for extra measure, but I think you'll find the Crisco works very well on it's own.  If you have an airbrush and can spray outside, the Vaseline and Acetone is the very best for fine detail like the tanks.  It doesn't take much for it to work as a barrier.  Thin the Vaseline as you would an acrylic paint so it can be sprayed.  Do all of this once you  have your first part set in the mold box for the second pour. 

Joe
MTL

[TrainCat2]

My Fav is Smooth-On Mold Release in aerosol form, but the liquid is also great. With the liquid, use sparingly. A little bit goes a long way.

http://www.smooth-on.com/Release-Agents-and/c9_1123_1226/index.html

[DKS]

My Fav is Smooth-On Mold Release in aerosol form, but the liquid is also great. With the liquid, use sparingly. A little bit goes a long way.

http://www.smooth-on.com/Release-Agents-and/c9_1123_1226/index.html

+1

[Ian MacMillan]

My Fav is Smooth-On Mold Release in aerosol form, but the liquid is also great. With the liquid, use sparingly. A little bit goes a long way.

http://www.smooth-on.com/Release-Agents-and/c9_1123_1226/index.html

+1 here also. Its the same stuff I use with great results.

[delamaize]

Looks like I gotta get me some of that stuff, thanks guys.