# spray foam



## danellis1229 (Jan 24, 2013)

is there a specific great stuff to use there are several different types listed
are they all fish safe


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## danellis1229 (Jan 24, 2013)

danellis1229 said:


> is there a specific great stuff to use there are several different types listed
> are they all fish safe


can anybody please answer


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## jrill (Nov 20, 2013)

Maybe nobody knows.


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## lochaber (Jan 23, 2012)

I'm not familiar with all of the varieties offered, but I think a lot of the people just use the basic "Great Stuff". Sometimes people use the stuff specially designed for ponds, but it's quite a bit more expensive (it is black colored though. I've heard a couple claims that it holds up better under water, but if you are coating it with something, that won't really matter.

The only thing I would worry about is if it had specific anti-microbial or anti-fungal additives. Other than that, I think most of it is just straight polyurethane foam, with a few varieties for different expansion rates. 

Using one with a lower expansion rate might be easier to work with, I'm assuming it would have less/smaller gas bubbles, but that's just a guess on my part. It would be easier to plan it, since it would end up curing in closer to the shape/size you get shortly after applying it.

I think I've even heard of people just using gorilla glue, by applying it to the background in a thick coating, and then spritzing it with water to get it to foam up. I've got no experience using it this way myself though.


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## shawnwaldon (Dec 5, 2013)

I have seen people use the one that comes in the red can for gaps and cracks. Really though I don't think it matters what type you use because you will have to put something over the foam to protect it from the water in the aquarium and what you use for that is what needs to be "fish safe."


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## Aplomado (Feb 20, 2013)

Look here:

http://greatstuff.dow.com/products/pond-and-stone/


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## KribsDirect (Nov 15, 2013)

You need crack filler for ponds. Most times it is marketed as "waterfall foam".


Its a mess and I suggest buying an extra can because the first one will most definitely be a learning experience.

I gave up on trying my idea with the stuff but have seen lots of interesting applications. Good luck!


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## plantbrain (Dec 15, 2003)

You can use blocks of Styrofoam and melt them into the shapes you want with a propane torch etc. 

You can also make molds and use everything from silicone rubber to epoxy as material.

Various cements also work very well and then can be coated to seal the cement.


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## Diana (Jan 14, 2010)

Great Stuff is aquarium safe. No need to cover or paint it. 
It is ugly, though. Glaring yellow. 

The pond version is black, so works better cosmetically. It is a bit gooier than the construction material (though both are quite gooy). 

Once it sets up (especially on your hands or clothes) it won't come off. I had some coveralls that I got some of the construction stuff on several years ago, and it never came off. Skin has to grow out before the pond stuff falls off. (Does not hurt the skin, you just go around with black stuff smeared on you fingers for a week or so). 

Best way to use it:
Mask the area, if you are sticking it to the tank. 
Apply a small amount, but be very careful to aim it just right. Unlike most caulking and many other materials (aquarium putty...) it is almost impossible to move the foam around to new locations. Touch it with a stick or anything else and the foam collapses. You can add more on top of what you already applied if the first amount was not enough. Remove the masking while the stuff is still wet, but be careful not to drag the tape through the wet goo. 
It is tricky to dust it with sand or anything. The weight of the sand just collapses it. 
If you apply too much, or it swells up too much it is very easy to trim after it is FULLY cured. This may take overnight for thick applications. It cuts with a sharp knife or razor.


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## danellis1229 (Jan 24, 2013)

thanks for all the responses i will be sure too post a pic of the creation if whats in my head materializes hmm maybe i should find a 3d printer lol


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## Turningdoc (Apr 2, 2014)

Another tip. If possible, tip tank and use only on horizontal surface. If it sags and dries permanently, it's depressing! You can use Krylon fusion spraypaint to color however you want as long as it cures 24+ hrs will be fine.


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## wildcat (Jul 14, 2014)

How'd this turn out? I'm getting ready to do the same.


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## danellis1229 (Jan 24, 2013)

still trying to get exactly what i want getting close


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