DIY Plywood Tank Built, but leaks, need help

[mick11]

As stated I have built the tank and have done three test fills. I would correct a leak and a second would appear. Aggravating that I'm good with DIY projects and having this issue.

Tank is 10' x 4' x 2.5' All seams are doubled up 2"x4"'s. Plywood is 3/4". Build like a Brick S#$% House. Glass is 3/4" tempered

Pond Armor was used to seal.

Pic is in the thread.

My plan now is to pop out the window and put on another coat of sealant. I spent a lot already on the pond armor, and would like to put on a couple polyurethane coats to save some $$$. Any suggestions on a good polyurethane.

Thanks

Mick

 

[mick11]

Just found this in another thread. I have moved the tank several times.

Thanks. The problem was Pond Armor. There is apparently a tiny bit of movement when I climb in and out of the thing, and this caused stress cracks between pieces of wood. I spent a long time trying to get the epoxy to work, including siliconing the stress points, but its too brittle. Finally, I switched to Sanitred and it worked right the first time. It was up for a while before it leaked as I try to avoid climbing into it. The Sanitred is immune to any flexing.

 

[yayfish24]

Looks good. What are you putting in it?

 

[mick11]

Right now I have to Motoro rays, but would like to get Frontosas instead.

The rays are getting big, so I need to get this tank working.

 

[yayfish24]

How big are your rays? Do you have any pics?

 

[Pharaoh]

Glad to hear you have it figured out. Tank looks good.

 

[kdrun76]

I have a tank build in progress, you may have just saved me some trouble.

Good luck.

 

[mick11]

Glad that an issue with pond armor has come up. The stuff was expensive and isn't working. Looks like the liquid rubber (EPDM) would be a better option. 1st off it works, always a positive. It's also less expensive. I'm sure some have used pond armor and have had no problems. Wish I was one of them.

Maybe a Lessons learned in plywood building would be a good thread.

I built this tank to last decades. Structurally, it's way over built, but since weight isn't a huge issue for me, that's just fine. A good coating that is flexible and won't crack is huge. I want to know that I can move this tank if I need too. I don't want to worry that it will leak if I lean on it while cleaning. In 30 years after I'm done, my wife can bury me in it. Thanks for all replies.

 

[john73738]

Nice build. Good to hear that you got the problem figured out. Great info and agree on having a lesson's learned thread.

Bear