# Great Stuff - Curing questions - Too thick?



## Caudex (Jan 28, 2013)

I began laying down the Great Stuff foam back ground last night. When I woke up this morning it seemed dried and cured, it felt pretty solid. But when I began carving I noticed it was still very wet and nasty down inside. 

Has anybody else done thick layers with this stuff?

Will it eventually cure down inside? Or do I need to rip it out and start over with dong thin layers, letting them cure between coats?


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## Mantella71 (Oct 7, 2013)

The deepest layers take a few days to cure if you foam all at once. Since you already started carving the pressure will force some of it out and create some funky shapes. Just cut those chunks out and let it cure for another day or two. How big is the tank?


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## tardis101 (Apr 11, 2012)

I usually let the thick areas sit for 2-3 days before cutting into it. You can usually tell the same as you can when baking, stick a sharp knife into it and pull it back out. If it's gooey then it's not done.


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## Caudex (Jan 28, 2013)

But it will eventually cure down inside for sure right?

its 48 wide by 32 tall 18 deep so roughly 120 gallons


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## Dendro Dynasty (Jul 11, 2013)

I let mine sit for a few days, and if you look behind the tank and you can still see wet spots use a toothpick and pierce it and let it cure. Mine I just stabbed with a knife. And yes it should all cure and if you run into any big holes while cutting just spray more foam in them.


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## Mavpa (Jan 5, 2015)

Dendro Dynasty said:


> I let mine sit for a few days, and if you look behind the tank and you can still see wet spots use a toothpick and pierce it and let it cure. Mine I just stabbed with a knife. And yes it should all cure and if you run into any big holes while cutting just spray more foam in them.


Yeah, after about 12 hours I go after all the thick spots with a wire coat hanger and poke holes to get some air in there. I wish I still had the picture, but sometimes the foam will re-expand through these tiny holes and make weird foam protrusions. They break off easy enough, but are cool looking when they first show up.


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## tardis101 (Apr 11, 2012)

Caudex said:


> But it will eventually cure down inside for sure right?
> 
> its 48 wide by 32 tall 18 deep so roughly 120 gallons


Yes it will eventually all cure.


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## TheCoop (Oct 24, 2012)

48 hours should be plenty, just about ready to start my 48x24x48 custom Frilled build background 6 cans of spray foam ready to go


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## tomagood41 (Oct 23, 2015)

Nice, I started with great stuff today on a 120. My first vid....look forward to seeing your build!


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