Unhappy Rookie Mistake-Great Stuff Background failing!

[MarcNem]

It's been almost 4 weeks since I began construction on my 18" Exo cube. I used Great Stuff foam for the background (and sides), which I let cure for almost 2 weeks. Then I put a generous portion of silicone on the background and pressed in a coco fiber mixture. About 10 days later I planted it. I checked it one last time today, and I noticed that the background was beginning to separate from the glass, and there was a 1/4" space between the foam and glass. I have never had this happen before with a foam background.
I also normally seal all the way around the GS, to make sure there is a good seal to the glass, in case the GS shrinks. I did not have enough space between the black plastic rim of the tank and the top of the foam. So, it was bare, but visible.
I believe the problem was a combination of two things.
1) I used a very heavy piece of Malaysian driftwood. This wood is very dense. I did not support it in any way, except for the GS foam, and the weight of the wood pulled the foam away from the glass.
2) I did not seal the GS all the way around the glass with silicone. This would have helped support the weight of the wood, and keep the foam against the glass.
The goo news is the tank is not ruined. But I am going to have to figure out how to support the wood, and stuff some moss between the crack, so the frogs won't squeeze back there.

I guess the moral of the story/lesson learned when using GS for a background with Malaysian drift wood, is to make sure you put enough GS to support the very heavy wood and make sure you silicone all the way around the GS, making sure there is a good seal to the glass.

The part that really sux, is I was planning to put my new 1.2 Cayo de Agua pumilio in there. Guess they gotta wait a lil longer.

Below are a few pics of the damage:









If this helps one person, then it was worth posting.
Thanks

 

[Matt K]

I am suprised to see that GS does not stick to glass. I thought it would have been stuck for good.

 

[thrower]

Was this a new tank? If it had been used before, it would probably be pretty hard to get the GS to stick.

 

[MarcNem]

It was a brand new tank. I only washed it with warm soap ad water. I was thoroughly dried before I added any GS. Someone else recommended I coat the glass with silicone prior to using the GS. As for this project, I added a large amount of silicone in the gap and clamped it. I am letting it dry for a few days. I will post pics and keep everyone updated.

 

[MarcNem]

This is how I fixed the background.

This is how I repaired my Exo 18" cube, after the back started to separate from the glass. I added a huge goob of brown silicone to the space, then coated it with my coco fiber special mix (dried coco fiber, tree fern root, and bark) and clamped it. I allowed it to dry for a week, and this is how it came out. Seems ok. I plan to put a pair of El Dorado pumilio in there.

I goobed the silicone in the space between the GS and glass.


I coated the silicone, then covered it with coco mixture


:banana:
View of the front of the tank


Close-up of the viv floor


Regards,
Marc

 

[Tdizzle10]

lol you got pwned noob

see what I did there? :biggrin:

 

[MarcNem]

lol you got pwned noob

see what I did there? :biggrin:

pwned Huh?

 

[josh_r]

when great stuff cures, it forms a nice waterproof exterior surface. the surface attached to the glass however, is very porous. when water gets between the glass and great stuff, it causes the foam to detatch and shrink. there is a really easy way to prevent this from happening. before you spray great stuff onto the back of your viv, get some lighting egg crate (home depot has it) and cut a piece to fit the back of the vivarium. silicone this in place and let it cure for a couple days. make sure you silicone very thoroughly as this is going to support the weight of your background. ince it is cured, simply make your great stuff background as normal. the great stuff will "bite" onto the egg crate and hold on VERY well. i used to make the same mistake when i first started making vivariums. it got really frustrating after a while as i would sometimes find my frogs behind the background. anyhoo, good luck and hopefully it wont get any worse.

my old 150gal. with the technique explained above, i was able to secure a 20 or 30lb rock to the back of the aquarium. i have made others with about 75lbs of rock that held amazingly!

one of my old 30gal cubes

heres another 30gal cube with malaysian trapdoor spiders in it.

these were all made using egg crate on the background before foam was added and i never had any issues with the backgrounds coming off.

-josh

 

[Grendle]

Beautiful tanks!! I use black silicone on the back first, then a plastic grid over a thin a layer of silicone to hold it then the next day I do the great stuff and add decor...that way the great stuff grabs on to the plastic grid too.