Plasticine and latex- something went wrong...

[tefstudio]

I made a relief sculpture out of Plasticine (Roma Plastalina) and attempted to make a mold with Cementex Latex. I have only made a few sculptures like this before and that was years ago in college.

When I took the latex off the sculpture, the inside of the latex was distressed in a way that it's not supposed to be. Here's a pic:

http://home.earthlink.net/%7etefstudio/latex.jpg

I did this kind of sculpture years ago in college but never had this happen. I did about 15 coats of latex, waited hours between coats and was very careful with the first coat.

The only thing I can think of that caused this was that I used quite a bit of Turpenoid to smooth the plasticine (I never did that previously but read many places online that it was OK). I'm assuming the Turpenoid in the plasticine caused the distressed texture inside the latex mold?

Does anyone know if the Turpenoid caused the distress in the latex? If so, how can I avoid this in the future?

Also, will I be able to use the plasticine sculpture now to make another latex mold? Do you think it will be OK now?

Any help/advice would be appreciated! Thanks!

[repeat.process]

As Roma is an oil-based clay, it probably contains petroleum jelly, which weakens or destroys the structure of latex. So this could be the reason for the surface damage you have on your mold. Maybe you could try to seal the sculpture with a few coats of sprayable sealant/fixative, let it dry completely and re-try the molding procedure, but I'm no expert on this.

[tefstudio]

As Roma is an oil-based clay, it probably contains petroleum jelly, which weakens or destroys the structure of latex. So this could be the reason for the surface damage you have on your mold. Maybe you could try to seal the sculpture with a few coats of sprayable sealant/fixative, let it dry completely and re-try the molding procedure, but I'm no expert on this.


I don't think it's the oil based clay. We made relief sculptures with Roma plasticine and latex in college and there were no problems.

The fixative idea sounds good. That would definitely help if I try this again with the same plasticine sculpture.

[Kaete]

It might be the sulfur in your roma plasticine - it can play merry hell with lots of mold materials. You either need to get a non-sulfur oil clay like Klean Klay or use a protective coat of something to keep the mold-making material from being contaminated.

If it is the sulfur, chances are in college you might have used a release agent or spray on varnish and forgot about it.

Maybe you should try a couple small tests before attempting another mold? Do one with just the clay, one with the clay and the turpenoid, one with clay and spray-varnish, one with clay and turpenoid and spray varnish. That way you'll be able to isolate the problem and know which method works best.