DIY mistake

[yohann976]

I have a 90 tank and I wanted a natural looking background. So I took a sheet a foam 2" thick (from Lowes) and shaped it into what looks like a rock formation along the whole back wall of my tank. Then I coated it with several layers of epoxy. It actually looks really cool.

The mistake that I made is when I caulked the sheet of foam onto the back of the tank. I made a bead of caulk in a random circular motion. Now, there are many areas behind the foam that will trap air when the tank is filled with water because of the caulking pattern and epoxy leaking behind the foam.

Is this going to be a problem. I am worried that having different points of pressure on the back wall will crack it. I thought of maybe drilling small holes in different areas in the epoxy and foam to release the air pockets. Does anyone have any thoughts to this?

[dskidmore]

Are these air pockets completely surounded, or just prevented from moving upwards? Bubbles exposed to the water can disolve over time, so you could just fill the tank slowly and wait them out. Other than that, the drilling option might work. Be sure to re-epoxy the holes.

How big are these bubbles? Are you certian it will be a problem? As long as we're not talking about a point load situation, I don't think this will hurt anything. Is the power of an air bubble greater than the weight of a rock? People stick rocks to the back of the tank all the time.

[yohann976]

Some of the air pockets are completely surrounded by caulk but most of the air pockets are just being prevented from going to the top. The pockets are irregularly shaped, but I can estimate that they are around 3-6 inches in diameter and 1/16" thick, spaced along the back wall. There are about 10 of them.

[dskidmore]

I don't know as if I'd really be worried.

[BillyZ]

if you could snap a picture of it so we can see it we'd be more sure, but I'm leaning towards agreeing with skids, don't worry bout t.

[greenmaji]

I cant think of any reason why air would be that much of a problem.. water on the other hand could be, if you desided to drill holes would you be able to evacuate the areas of air? I kinda doubt it, you would have to fill them with silicone or something.. If the background is water-tight you should be fine..