# Using a mold for use with expanding foam



## Guest (Oct 26, 2004)

Here's my idea... but I'm wondering if anyone can help this idea along. I want to use expanding foam and apply it to a shape. To make it simple, let's say the outside of a food bowl. After the foam has hardened and cured, I'd like to be able to unattach the foam from the bowl w/out ruining the foam shape I have created. Is there something I can apply to the bowl that would keep the foam from attaching to it - so I can just peel the bowl mold and the cured foam from each other? (and still retain the shape of what I cast the foam on)

Any help, much appreciated!


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## Mantellaprince20 (Aug 25, 2004)

I have no idea, but maybe try flour. Hmmm, other than that, I am out of ideas.


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## pa.walt (Feb 16, 2004)

you would need some sort of a mold release. if you have any sort of art stores by you go there and they usually have a casting/molding section. it would be on the "greasy" side. you could also try these "homemade" mold releases, vasaline or maybe even like a pam cooking spray. 
worse comes to worse you could wrap the bowl in plastic wrap and then coat it if you aren't picky how the inside would look.


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## melissa68 (Feb 16, 2004)

At the MDG meeting in Indy at Scorpion's place, we discussed this topic.

I am sure he can make some additional comments here, but he was using a small rubbermaid tote and using the one of the bottom corners as a mold. When it was set, he would pop it out, and he had a corner piece ready for his tank.





RoLLi said:


> Here's my idea... but I'm wondering if anyone can help this idea along. I want to use expanding foam and apply it to a shape. To make it simple, let's say the outside of a food bowl. After the foam has hardened and cured, I'd like to be able to unattach the foam from the bowl w/out ruining the foam shape I have created. Is there something I can apply to the bowl that would keep the foam from attaching to it - so I can just peel the bowl mold and the cured foam from each other? (and still retain the shape of what I cast the foam on)
> 
> Any help, much appreciated!


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## Guest (Oct 26, 2004)

I was thinking Pam or other cooking spray too. It's non toxic and cleans up easily.


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## Ryan (Feb 18, 2004)

Also by making it so you can inject air would cause it to break away. thats how they do it with boats.

Ryan


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## Guest (Oct 26, 2004)

I used a trash bag with some experiments and you can peel it off without any problems.
j


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## Guest (Oct 26, 2004)

*mold*

If the bowl is poly, you won't need any mold release. 
I have done lots of casting (part of the business I'm in) and mineral oil is a good release as well.
Being that you are using this for frogs, I think the pam or a vegetable oil would work well for you. Again, you very well may not need any.
Good luck.

Saran wrap is good, as well as clear packing tape. These are a bit harder to keep in place and/or comform to freeform shapes.

On wood and very porious material, waxes like Butcher's bowling alley wax, applied rubbed down and reapplied and rubbed down to build up a few coats will work. 

As with all things, do a test first, as Murphy has a way of rearing it's head!


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## Guest (Oct 26, 2004)

*These are good suggestions.*



MR2 said:


> If the bowl is poly, you won't need any mold release.
> I have done lots of casting (part of the business I'm in) and mineral oil is a good release as well.
> Being that you are using this for frogs, I think the pam or a vegetable oil would work well for you. Again, you very well may not need any.
> Good luck.


Well, my example of a bowl was to simplify what I was trying to say. Actually, I want to make a mold from a rock I found. The inverse of it's shape is exactly what I want as a pond/water feature shape. These are all
good suggestions... and hopefully I can use this rock, or I just may have to make a mold from something else. I'm going to experiment with it sometime this week. Thanks!


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## Guest (Oct 27, 2004)

*mold*

If the rock has lots of undercuts, you may want to use some modeling clay to create draft. If not, you will lock onto the rock in these areas.

I would possibly use Cisco lard. Warm some up for the overall brushing on, sealing pores, ect. and the thick for the "minor" areas of undercuts. Do the claying (if needed) first and put release right over this.


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## Jordan B (Oct 8, 2004)

Wax paper?


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## Guest (Oct 28, 2004)

> Wax paper?


thats what i was thinking! 

I was pondering using molds as well. 
On a side note, I have a resapy for birdbaths using portland cement perlite and peat and i dont think it would be acidic or leech once dried. u could make some cool ornaments with a mold and and something to pour into it. 
What else can i use that has a no toxins or acidity once dried, that i can pour into a mold?


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## dec (2 mo ago)

Guest said:


> I used a trash bag with some experiments and you can peel it off without any problems.
> j


are you saying that it won't stick to a plastic bag? ie as you say, it will just peel off? that seems unlikely as it seems tyo stick to just about anything.


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## fishingguy12345 (Apr 7, 2019)

dec said:


> are you saying that it won't stick to a plastic bag? ie as you say, it will just peel off? that seems unlikely as it seems tyo stick to just about anything.


This thread is 18 years old and the people who have posted on this thread are not active users any more. If you have questions about using spray foam please start a new thread.


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