# Molding Great Stuff foam



## sbbbugsy (Sep 24, 2005)

Question: As Great Stuff hardens, does it reach a point where you can mold it by hand?

I want to cover a giant skull and recreate a head/face for it.

Steven


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## Sychoclown (Sep 1, 2005)

No it's somewhat rigid and spongy. You can carve it or grind it. I used a dremel to reshape it. I would use a grinding stone to shape it. It's easy to work with , but a little messy.


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## Haunted Plainfield (Mar 18, 2005)

Until it hardens it is sticky. I don't mean...oh look you have something stuck on your shirt let me get it off, I mean, when it dries it is there until it breaks down. On your hands 2 - 3 days or so.


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## madmax (Dec 28, 2003)

Yes and no....I often take my project out of the mold before it's fully cured and shape it. But there's a limit to how much shaping you can do. I don't think you'll be able to shape the foam into detail shapes.

Most of the time when I try this...it's usually just to shape the fingers or palm of the hands. Sometimes I will try to help shape a deformed head.

Like these half arms and head....the hands were a life cast and flat. I took them out while the foam was some what soft and pressed, bent and squeeze them till the palm and fingers were the shape I needed.


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## babygirl_kmp (Sep 27, 2005)

ok so since we are talking bout molding with great stuff... I have a quesiton. I bought 2 plastic bats last year and finally found a place for them. I want to use them on the front of my columns but had some trouble attaching them to it. I have one bat left and was thinking of filling the hallow bat with great stuff and making a mold of it. What can i use to make the foam not stick to the hallow bat? I have tried cooking oil but that left the foam with little tiny holes in it. I seen someone on here use baby oil but that seems to not work either. I do not want to ruin my bat if possible because I can not find another one. Anyways does anyone have any other suggestions? And sorry for the steal.


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## madmax (Dec 28, 2003)

That's the problem with great stuff...you might get one cast to turn out without any defects and the next with the tiny bubbles in it. I use vaseline but most of the things I cast doesn't need fine details.


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## sbbbugsy (Sep 24, 2005)

*Molding*

A few things i've discovered today:

1. Vasiline does help to keep Great Stuff from sticking.
2. Keep the flow rate very slow to get into small areas.
3. If you spread it by hand and squish out the air, it will still foam (expand) some and be even harder. This technique might work well for makins castings like the bat mentioned above.
4. When the surface has hardened somewhat, you can press and move it around to help shape it.

Steven


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## babygirl_kmp (Sep 27, 2005)

vasiline eh.... will have to try that.... thanx


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## cuvers (Aug 3, 2010)

was also wondering about shaping while it is not dry, I know it is kinda like melty marshmallow ish, but if wearing gloves and getting them wet wouldn't that give you more sclupting access?


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## partsman (Oct 18, 2007)

babygirl_kmp said:


> ok so since we are talking bout molding with great stuff... I have a quesiton. I bought 2 plastic bats last year and finally found a place for them. I want to use them on the front of my columns but had some trouble attaching them to it. I have one bat left and was thinking of filling the hallow bat with great stuff and making a mold of it. What can i use to make the foam not stick to the hallow bat? I have tried cooking oil but that left the foam with little tiny holes in it. I seen someone on here use baby oil but that seems to not work either. I do not want to ruin my bat if possible because I can not find another one. Anyways does anyone have any other suggestions? And sorry for the steal.


You could take the bat and press it into sand and cast the great stuff in the sand like I did in this thread: http://www.halloweenforum.com/tutorials-and-step-by-step/113831-sand-casting.html
It all depends on your final use for the bats is.


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## annamarykahn (Oct 4, 2009)

personally i like the defects that great stuff foam yields ... each casting is unique and more "organic" looking than perfect castings

i use "personal lube", the cheapest that i can find ... its water based so, along with releasing the casting from the mold it also speeds up the curing

i did a comparison of some of the various great stuff products in a thread here => http://www.halloweenforum.com/halloween-props/140413-great-stuff-foam-comparison.html

amk


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## lawrie (Aug 4, 2015)

How much is Great Stuff? In England the only place I can find it want £15 a can. Generic expending foam is £5.


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## EdgarWhelp (Mar 20, 2014)

Great Stuff isn't anything special - it's just the one lots of people around here recommends. The generic stuff I use produces exactly the same results.


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## ScareCrowe (Oct 18, 2007)

babygirl_kmp said:


> ok so since we are talking bout molding with great stuff... I have a quesiton. I bought 2 plastic bats last year and finally found a place for them. I want to use them on the front of my columns but had some trouble attaching them to it. I have one bat left and was thinking of filling the hallow bat with great stuff and making a mold of it. What can i use to make the foam not stick to the hallow bat? I have tried cooking oil but that left the foam with little tiny holes in it. I seen someone on here use baby oil but that seems to not work either. I do not want to ruin my bat if possible because I can not find another one. Anyways does anyone have any other suggestions? And sorry for the steal.


Ok, even though this post is like 9 years old, lol, I want to pipe in with my discoveries.
The absolute best thing I've found to prevent sticking with Great Stuff is Minwax brand paste finishing wax. It doesn't stick to it. You can coat your mold with it and have no problems. You can also wear rubber gloves coated with it and work the foam without worry of it sticking or pulling out of shape. 
For the hollow bat I would cut one side lengthwise, coat (the inside) with the wax, spray the foam in it, moderately mist the inside with water then close and tape it back together until it cures.
The finishing wax and a water spray bottle are #2 and #3 on my list of absolute needs for working with Great Stuff. (Great Stuff would be the #1)


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