# Newbie Styrofoam Background Question



## dartsinmanhattan (Apr 11, 2018)

I'm a newbie making my first background for my 75 gallon dart frog vivarium. I'm going for a stacked slate look using glued-together strips of different thickness Styrofoam with the edges distressed using a hot knife. The whole business will be coated with Hot Wire Exterior Foam Coat. My question is do I make the background the full height of the tank and cover the first 4-5 inches in substrate and soil, or do I make it shorter and glue it to the back of the tank above ground? Also, what should I use to glue it to the back of the tank? I've heard either silicone or hot glue...


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## TokayGenetics (May 24, 2018)

dartsinmanhattan said:


> I'm a newbie making my first background for my 75 gallon dart frog vivarium. I'm going for a stacked slate look using glued-together strips of different thickness Styrofoam with the edges distressed using a hot knife. The whole business will be coated with Hot Wire Exterior Foam Coat. My question is do I make the background the full height of the tank and cover the first 4-5 inches in substrate and soil, or do I make it shorter and glue it to the back of the tank above ground? Also, what should I use to glue it to the back of the tank? I've heard either silicone or hot glue...


I usually keep it a few inches off the bottom to make sure a bunch of foam is not sitting in the soil. But I do bring the soil level to just above when the foam starts. To glue it to the back of the glass you should use silicone hot glue might not last. I use GE clear silicone.

Sent from my SM-G950U using Tapatalk


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## dartsinmanhattan (Apr 11, 2018)

Thanks for the input! When I silicone the background to the back of the tank, do I have to coat the whole back to eliminate any pockets that might grow bad stuff, or can I just put a bead around the outside edges and a few X's across the rest of the back?


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## Khamul (Jan 16, 2018)

The latter should be just fine


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## jgragg (Nov 23, 2009)

> The latter should be just fine


+1, no need for 100% coverage (unless you care what it looks like from behind - I tend not to). Just lay a thick bead down all the way around the perimeter and also maybe dab on a grid (every 6" or so?) of blobs inside the perimeter, then when you lay on the foam really press it down to flatten & spread the silicone. If you have any "wiggle room", work the foam back and forth a little to spread the bead & blobs into an inch or two wide strip or spots. When you're done pressing & wiggling, lay some weights on the foam to keep it from popping up off the glass any, until the silicone cures. I like to ensure no water can ever get behind there. It just prevents any issues whatsoever from arising.



> Hot Wire Exterior Foam Coat


Interesting, first I've seen this. Are you confident it's pet safe? 

My current build (36x18x36 Exo) is getting brushable epoxy over its pink-foam background. https://www.smooth-on.com/products/habitat-cast-coat/ It's my first time using that product.

Previously, on maybe a half-dozen full-background builds, plus numerous components like ledges, water bowls, and hides, I've used an epoxy putty (Zoopoxy from Polygem) over foam; I really like the zoopoxy, it is incredibly durable and takes texturing and coloring very well. The brushable stuff may be even better in the application phase (brush, not trowel), but like the putty it has a learning curve to efficient & tidy use. The consistency is a bit like honey, and it keeps flowing for quite a while. It takes acrylic paint just fine, but I haven't quite mastered texturing yet. On the plus side, it preserves whatever details you carved into the foam very, very well (unlike the putty).

Anyway, just sharing. There's multiple paths to enlightenment in this addiction I mean hobby. Ha ha ha.

Good luck!


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## dartsinmanhattan (Apr 11, 2018)

Thanks for the info. The tank is a 75 gallon glass tank that's built into the stand, so I can't tip it on its back to put weights on it while the silicone dries, so I will have to cut some Styrofoam strips and wedge them in between the background and the front glass. 

I spoke to a couple of people at Hot Wire and they said its very hard, non-toxic, and waterproof. I will be putting in an additive called Boost that makes it virtually bulletproof, and they even have grit that you can add it in give it a stone texture. Apparently zoos use it all the time.


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## jgragg (Nov 23, 2009)

Ah, good to know it's animal-safe. Although, I did some checking on their FAQs site and saw this:



> ...The Foam Coats are concrete based products...
> 
> Q: I made a foam background for my aquarium – what can I use to safely coat it?
> 
> ...


So...there's that to consider. It could be that a lot of rinsing to bring down the pH is in order. Or, just seal it as they suggest here.

I may have to give this stuff a try as well - thanks for bringing it to our attention @ DB. I have never seen it discussed here - people mostly seem to stick with what they know (e.g., smearing silicone over foam, and then pressing coco fiber into it; none for me, thanks!). I do like my epoxy, but I also like to keep looking for better stuff.

Also thanks for bringing the company to my attention. Despite what I said about "looking for better stuff", I'm still using serrated knives to cut foam. I'm gonna look into a decent-quality hot wire knife. At least I could use it in the summer, in the garage with the door open!

cheers


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## dartsinmanhattan (Apr 11, 2018)

jgragg- they make a spray-on coating called Stain Fast that can also be tinted to color the background. Goes on with a regular spray bottle. Check their site--hotwirefoamfactory.com. They have a lot of great products and how-to videos on there. 

There's a guy there named Dave that has been very helpful--answered all my questions.


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