Rookie Mistake-Great Stuff Background failing!

Knoxter · 03-22-2009, 02:55 PM

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

Knoxter · 03-26-2009, 09:47 PM

I got a few suggestions on how to solve the problem. What I di was allow the tank to dry out. So, now there is no condensation between the glass and the GS. Then, I put a good amount of silicon between the two and clamped the back together. I will post pics tomorrow.

clthomps · 03-29-2009, 11:39 PM

If that doesn't work you could pour some poly-resin down the crack.

Knoxter · 03-29-2009, 11:54 PM

I already added a huge goob of silicone and clamped it. It only moved a lil bit because it already settled. Pics to follow soon.

Knoxter · 04-05-2009, 07:43 PM

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

View of the front of the tank

Close-up of the viv floor

Regards,
Marc

Kermit · 04-05-2009, 11:11 PM

I realize you already fixed your background problem but what i found that works is to use eggcrate for the back then put the great stuff on that. that keeps it from separting from the glass.

clthomps · 04-05-2009, 11:17 PM

Good Tip Kermit!

Glad to see you have it all taken care of

socaled · 04-09-2009, 12:30 AM

Ditto on eggcrate

03-22-2009, 02:55 PM	#1 (permalink)
Knoxter Administrator/SiteOwner Join Date: Mar 2009 Location: USA Posts: 430 Real Name: Marc Knox	Rookie Mistake-Great Stuff Background failing! 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 __________________ Marc My frogs- Vanzolini, El Dorado (ong&gold), Cayo de Agua, Almerante, Gold Dust, Yuris, Imis, Inters, Taras, O Lamasi, Iquitos Vents, Varis, SI. I appreciate everyone here. Without you, there would be no DFF. Thank you for your support.

03-26-2009, 09:47 PM	#2 (permalink)
Knoxter Administrator/SiteOwner Join Date: Mar 2009 Location: USA Posts: 430 Real Name: Marc Knox	I got a few suggestions on how to solve the problem. What I di was allow the tank to dry out. So, now there is no condensation between the glass and the GS. Then, I put a good amount of silicon between the two and clamped the back together. I will post pics tomorrow. __________________ Marc My frogs- Vanzolini, El Dorado (ong&gold), Cayo de Agua, Almerante, Gold Dust, Yuris, Imis, Inters, Taras, O Lamasi, Iquitos Vents, Varis, SI. I appreciate everyone here. Without you, there would be no DFF. Thank you for your support.

03-29-2009, 11:54 PM	#4 (permalink)
Knoxter Administrator/SiteOwner Join Date: Mar 2009 Location: USA Posts: 430 Real Name: Marc Knox	I already added a huge goob of silicone and clamped it. It only moved a lil bit because it already settled. Pics to follow soon. __________________ Marc My frogs- Vanzolini, El Dorado (ong&gold), Cayo de Agua, Almerante, Gold Dust, Yuris, Imis, Inters, Taras, O Lamasi, Iquitos Vents, Varis, SI. I appreciate everyone here. Without you, there would be no DFF. Thank you for your support.

04-05-2009, 07:43 PM	#5 (permalink)
Knoxter Administrator/SiteOwner Join Date: Mar 2009 Location: USA Posts: 430 Real Name: Marc Knox	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 View of the front of the tank Close-up of the viv floor Regards, Marc __________________ Marc My frogs- Vanzolini, El Dorado (ong&gold), Cayo de Agua, Almerante, Gold Dust, Yuris, Imis, Inters, Taras, O Lamasi, Iquitos Vents, Varis, SI. I appreciate everyone here. Without you, there would be no DFF. Thank you for your support.

04-09-2009, 12:30 AM	#8 (permalink)
socaled Senior Member Join Date: Apr 2009 Posts: 350	ditto Ditto on eggcrate

03-29-2009, 11:39 PM	#3 (permalink)
clthomps Member Join Date: Mar 2009 Posts: 36	If that doesn't work you could pour some poly-resin down the crack.

04-05-2009, 11:11 PM	#6 (permalink)
Kermit Member Join Date: Apr 2009 Location: Riverside California Posts: 43	I realize you already fixed your background problem but what i found that works is to use eggcrate for the back then put the great stuff on that. that keeps it from separting from the glass.

04-05-2009, 11:17 PM	#7 (permalink)
clthomps Member Join Date: Mar 2009 Posts: 36	Good Tip Kermit! Glad to see you have it all taken care of

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