Help! Plywood tank seams leaking!

[Valum]

Advice needed I recently built this tank 90gallon plywood tank my seems appear to be leaking and capillary action is making it soak onto the wood

I've fibreglassed the seals and covered with pond paint, I've then used pond seal to try and stop the leak but this has failed

Please help I've had to put the fish in QT and corals in a box

 

[Valum]

Test filling at 160L atm, going to leave it overnight

 

[Shooter6]

I recommend you put sheets of 3/4 plywood on all exterior walls. That will help stiffen it up and avoid any flex causing leaks.

 

[Valum]

I recommend you put sheets of 3/4 plywood on all exterior walls. That will help stiffen it up and avoid any flex causing leaks.

I assume you mean on the initial tank?

The tank has been rebuilt in further comments to 2 sheets of 18mm plywood similar design to Joey's but not as long

 

[Staghorn]

Fingers crossed buddy good luck

 

[Shooter6]

I assume you mean on the initial tank?

The tank has been rebuilt in further comments to 2 sheets of 18mm plywood similar design to Joey's but not as long

I mean on the outside of the 2x4 braces. Laminating the 2x4 frame between the inner plywood, and what i recommended. This will add an incredible amount of strength to the entire structure.

 

[Valum]

I mean on the outside of the 2x4 braces. Laminating the 2x4 frame between the inner plywood, and what i recommended. This will add an incredible amount of strength to the entire structure.

The external structure was fine, it was the voids in the structure that gave it weakness the only option would have been to fill the inside with support

 

[Shooter6]

The external structure was fine, it was the voids in the structure that gave it weakness the only option would have been to fill the inside with support

That very may well becthe cause of the failure, but that does not mean theres not additional ways to strengthen this tank.

 

[Valum]

That very may well becthe cause of the failure, but that does not mean theres not additional ways to strengthen this tank.

I'd agree with you on that but as many people highlighted it was easier to start from scratch rather than patching the old one

 

[Shooter6]

I'd agree with you on that but as many people highlighted it was easier to start from scratch rather than patching the old one

I agree too, but i was speaking of the design, not patching.
In may opinion there were flaws in the sealing process and design but ill reserve that .

 

[Valum]

2 days in fully filled and so far so good

 

[Valum]

Fingers crossed my corals pull through hopefully now in a bigger tank with better stability

 

[mjovic]

Thanks for taking us through this journey and showing us the good and the bad. I'm contemplating building a plywood tank and it's helpful to see real world examples of where the weak points are. It's always easier to OVER engineer something, just slap on some more layers/bracing, etc. But knowing where the limits of failure are can help in overall planning. Wondering how the tank is holding up several months later. Any updates?

 

[Valum]

Hi guys sorry for the lack of updates fully rebuilt the tank using 18mm plywood 6 months or so in and no leaks

 

[Valum]

The Next yep is getting the plaster smooth and paint then I will make some doors for the lower portion, the access to the upper portion is via a sliding door

 

[Valum]

 

[Valum]

I was hesitant to move on with the project for so long I have only just this week gained the courage to plaster board and plaster the tank

 

[Valum]

No fish at the moment put healthy coraline algea growth

 

[salty joe]

Excellent! Keep us posted on the cabinet.
I've had water in my plywood tank for seven years. I love a plywood tank!

 

[albano]

I've had water in my plywood tank for seven years. I love a plywood tank!

Serious question… why ?

 

[Valum]

Serious question… why ?

Personal preference, there not for everyone but there is many pros to them