Resealing a large tank

[kdrun76]

I am about to reseal a 450 gallon tank. It doesn't currently leak, but the silicone seals look awful. I bought the tank used and have had it full of pacu for 9 years. I want to reseal it BEFORE it leaks. Its a time bomb. The fish are out and I am currently in the process of emptying and cleaning the tank.

I have resealed a lot of tanks over the years, but nothing larger than 125 gallons. Is there anything different about sealing a really big tank I should know? Clean it up and use LOTS of GE Silicone 1 (All purpose).

The tank is 8' x 3' x 28". There is no trim on it anywhere. Its just a glass box with an overflow. I put decorative trim on the stand that covers the bottom edge when I built the stand 10 years ago. Now I want to put some sort of a rim around the top. Mostly I want to stack the odds in my favor that this tank isn't going to bow out when a 25 llb pacu gets spooked and decides it wants to be on the other side of the living room (which happens about 3x a day!) I also need to redesign the lid system for the tank as what I have now has done the job, but its awful. So I am looking for ideas of how to rim the upper surface and include a method of building a lid into that. I will probably use plastic lumber as I am a pretty good carpenter and that stuff doesn't rot when it gets wet. I will post pics of the current top when I get closer to that stage of this project, right now I need to get it sealed.

 

[krichardson]

Hmmm,seems odd for such a large tank not to have any trim,does it bow any?Though not as big as yours I resealed my 265 a few years ago and it's been high and tight ever since.

 

[krichardson]

Perhaps you could contact a few tank building companies and inquire about having some framing(with cross bracing of course) made.

 

[kdrun76]

Perhaps you could contact a few tank building companies and inquire about having some framing(with cross bracing of course) made.

Why not just make a frame myself? Is there some big advantage to the plastic trims over a wooden one? Clearly I can't mold plastics, but I do really well as a carpenter.

The tank has two cross braces built into it, but they are glass held on with silicone, and just like all the other seams...the silicone looks awful and needs to be replaced ASAP.

 

[krichardson]

If you can create a wooden frame then go go for it.My main concern would be damage and deterioration due to constant water exposure.

 

[kdrun76]

If you can create a wooden frame then go go for it.My main concern would be damage and deterioration due to constant water exposure.

plastic lumber https://en.wikipedia.org/wiki/Plastic_lumber

Its more flexible than wood and requires more support to prevent warping, but it doesn't rot and it cuts about the same if not better due to the consistent grain. Just like wood, pre-drill big screws to avoid cracking.

 

[krichardson]

Interesting,I have never heard of that.

 

[kdrun76]

I am about to give my sister a 70 gallon tank that I have owned for about 15 years. I have no idea how old it is. I am also about to reseal my big tank. Should I strip and reseal the 70 while I am doing it, or just give it to her? It has never leaked and the silicone looks perfect. Its been sitting empty for 2 or 3 years.

 

[Lepisosteus]

I am about to give my sister a 70 gallon tank that I have owned for about 15 years. I have no idea how old it is. I am also about to reseal my big tank. Should I strip and reseal the 70 while I am doing it, or just give it to her? It has never leaked and the silicone looks perfect. Its been sitting empty for 2 or 3 years.

Depends if you like your sister or not

 

[Matteus]

From what I understand, GE silicone 1 is not a good product to use for a big tank. I’m scared to use it on a 30 gal I have at home after having it fain on me in another application type earlier his year.