# help using great stuff for casting



## Herman Secret (Oct 1, 2007)

I have made a cast of a skull, first covering it with kitchen foil then papier mache. I was going to use this as a mold to cast a cast using great stuff. Can anyone help with a suggestion as to what I can coat the inside of the "mold" with so that the great stuff will not stick to the foil ? I was wondering if vaseline or "pam" would work ... help please 

Many thanks


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## Lynn (Aug 23, 2005)

Those may work but when I tried this, the great stuff didnt set up. There may be some secret out there I don't know but it didn't work for me.
If you get it to work, post it, I'd be interested in knowing how !


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## bw1 (May 31, 2005)

Great Stuff is not the best product to try to cast with. It needs air and moisture to cure. When you fill the mold the center will either not set up or it will take weeks to cure. See if you can find some two part foam. It comes in different weights. Two pound should be fine for what you are doing. You mix the two parts together and pour it in your mold and it expands about 16 time its original volume and fills the mold. It will be cured in about half an hour. They sell it here in two one quart bottles. Expand half a gallon 16 times and it goes a long way


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## superspeedfreek (Oct 21, 2006)

*trouble stuff*

You could also try centering securing an inflated balloon that is a bit smaller that your skull will have hollow center and not have so much foam that needs to cure. I'd also suggest making a few paper mache skulls, so you can have enuff itemss to fill, so that you can use up all of the can of foam, because it will not be usable once the foam dries up in the aerosol spray trigger. So have enuff things you want to fill whenever you're ready to use the can of foam. The manufacturer even states that after the can sits without being sprayed for more than a few seconds, it starts to setup and the can will no longer be usable due to foam that's cured in the spray trigger. They suggest to quickly clean spray tube w\ acetone and to clean the spray tube with a pipe cleaner & acetone the best you can, & then to gently stuff a clean pipe cleaner into the spray tube for best chance of being able to reuse, altho they're very clear that the can is only good for one time use only; and anything more than that is outside the scope of the product and they're not responsible if it doesn't spray foam again after it being used once. Oh you'll also want your skulls to be rather rigid, so be sure to use several layers of the newspaper to create a strong shell; expanding foam has different expansion properties, and the supermegaultra expanding stuff will push apart your paper mache cast. I hope some of that info might prepare help you achieve some kind of desireable results! -tmt-

err...hopefully you can understand my banter above. as I'm not going to try any corrections after message failed to post, and all of your words are lost, without any notice. Even worse, - I hate having to retype what you were wanting to express the first time around, cuz it never comes together quite like when you were ready to submit the initial post.


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## Madame X (Oct 15, 2007)

Herman Secret said:


> I have made a cast of a skull, first covering it with kitchen foil then papier mache. I was going to use this as a mold to cast a cast using great stuff. Can anyone help with a suggestion as to what I can coat the inside of the "mold" with so that the great stuff will not stick to the foil ? I was wondering if vaseline or "pam" would work ... help please
> 
> Many thanks


you will have to buy an non oil based product for a release agent. Vasoline breaks down the Great Stuff something with a silicone base is better.


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## Dr. Slickshill (Mar 15, 2005)

Sand casting works well with great stuff... pressing both halves of the skull into a box of damp sand, filling the resultant depressions with great stuff and combining the two cured halves would yield fair results.


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## Herman Secret (Oct 1, 2007)

Thanks for the comments and suggestions. I will do some testing to see what yields the best results, Although will hold off on the testing for a couple of weeks to allow me to finish a couple of other projects for my haunt


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