# foam skulls



## sps110264 (Sep 9, 2010)

hi all,
i have made 2 attempts to make a foam skull using a plastic blow-molded skull as the mold and great stuff for doors and windows--the problem is when i open up the mold a couple of days after i squirt the expanding foam it into the mold, instead of it being a nicely detailed skull, it's a liquid MESS!! any suggestions??
thanks,
shawn


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## tot13 (Jul 25, 2007)

Fill the skull in stages, not all at once, allowing each stage to dry thoroughly before going to the next.


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## TheOneAndOnlyKelly (May 7, 2009)

Expanding foam insulation (as I found out later) needs air to cure. By not getting exposure to air, the bubbles inside of it are just going to pop and collapse. Filling in stages, as mentioned by tot13, would help with that.


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## SEFD111 (Apr 21, 2010)

When I use expanding foam, I also mist it with a bit of water along with filling in stages. The light mist of water seems to help it cure faster and expands a bit more. Good Luck!


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## DarkShadows (Feb 6, 2006)

Use smooth-on's foam. The kind I use is foam-it 5. Works great and cures in 5 minutes.


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## cjbmaaaaaa (Sep 12, 2010)

DarkShadows said:


> Use smooth-on's foam. The kind I use is foam-it 5. Works great and cures in 5 minutes.


Where would you get that type of foam?


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## bourno (Jan 21, 2006)

Here is Smooth-on link to their foam

http://www.smooth-on.com/Rigid-and-Flexible/c10_1122/index.html?catdepth=1

I have bought from US Composites

http://www.shopmaninc.com/foam.html


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## Denhaunt (Aug 18, 2006)

Yup. After you consider all of the frustration you're experiencing the 2-part foam will make your life a lot simpler. I've bought from both of the above places (both have great service and ship quickly) but now I buy from BITY out of Texas. They've got an awesome series of how-tos on youtube that really go above and beyond to detail the process. Here's the link: http://www.shop.brickintheyard.com/Foam_c16.htm

I use the Polyfoam R5. Cures fast and is a 1:1 ratio mixture. Good luck.


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## cjbmaaaaaa (Sep 12, 2010)

I have a question, what if you just spray the great stuff foam on each side of the blow mold skull and not put them together? Like filling 2 bowls and leave the tops uncovered? Then as it expands you can trim the excess off and hot glue the 2 skull halves together. Granted it wouldn't be one solid piece but it might be worth a try since you have the stuff.


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## billman (May 3, 2006)

I used the same great stuff for a skull mold. I left mine for 2days. It was dry. It was during one of the heat waves. Hot all day all night. I left it in my shed. 

Another problem is it will shrink significantly after a couple of days. Once dry, I would seal it with paint or clear coat asap.


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## tot13 (Jul 25, 2007)

I filled some mache skulls with Great Stuff this weekend. And I'm talking about some really firm, many, many layered strip mache skulls. I got in a hurry and forgot that PATIENCE is the key to using GS. Here's what I _think_ happened:

I always fill skulls through the mouth and eyes. therefore they're kinda lying on the back of the skull. I used one can and filled about 1/4th of each skull and allowed to dry about 8 hours - not that 8 hours means anything, that's just when I came back and just had to fill some more. Of course, the foam had expanded nicely and was pretty firm. The second shoot, using a second can, expanded to fill or nearly fill each skull. Some of them expanded out of the eyes and mouth. And here is where I messed up.

I don't think I allowed enough drying time - it had only been an hour or two. In my defense this was Friday night when I couldn't sleep and was up until 5 a.m. And I had been hitting the dark rum kinda hard too, lol. So I trimmed away the overflow foam, which allowed air to reach the inside foam - again. Even though the outside of the foam was dry, I don't think it was dry on the inside. As it cured the next day, it's like it sucked the air from everywhere and now my skulls look like they've just collapsed on themselves. I think this is what OP was describing.

Now, instead of skulls, I have future zombie heads, lol.


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