Resealing a tank

[stewmiester]

Hello everyone!! I recently purchased a large used tank. I knew the tank had a leak in it. I decided to reseal it. the tank is leaking in the bottom back seam. I've researched everything possible to make sure I done this right. Razor blades and alcohol, done everything exactly like I was supposed to. Filled it up a quarter of the way, held fine. Waited a week then filled it up halfway. A few days later all the way. Held water fine. Waited a month fully operational, pumps running and everything. About 3 months later I come home and the tank is completely empty. Removed everything from the tank and I looked at my back seam. It had split perfectly straight right down the middle. It was still hooked to the back panel and the bottom panel but looked like it was cut with a razor blade in the center of the silicone. So I guess my question is, is there a stronger silicone? Is there something else I could do to make it stronger. A larger bead maybe? I've looked everywhere and can't seem to find a solution. Any help or information would be greatly appreciated. Thanks in advance!!

[Steveb]

You might want to ask a mod to move this to the DIY forum. This one is really about feedback on the RC site itself.

[stewmiester]

I started a new thread in the DIY! Sorry, and thank you!

[Steveb]

no worries, I just wanted to make sure your question gets answered.

[thegrun]

You don't tell us what size "big" is but assuming it was over 150 gallons I would have advised waiting at least two months before testing it, you didn't give the silicone enough time to cure. You also did not list the brand and model of the silicone. If you didn't use a high quality structural silicone it was going to fail even if you let it cure.

[stewmiester]

The tank is 265 gallons and I used GE II silicone. I let it cure for 24 hours

[thegrun]

Originally Posted by stewmiester

The tank is 265 gallons and I used GE II silicone. I let it cure for 24 hours

GE Silicone II would not be considered a good structural silicone. It's fine for small projects will little stress, but you should use something like the Momentive RTV silicone for high stress applications coupled with adequate curing time.