Acrylic Tank Seam Reinforcement

Bigofishys

Gambusia
Original poster
MFK Member
Dec 8, 2014
16
12
8
Sacramento
Hello All,

I’ve seen people talk about acrylic tank repair but couldn’t really find any videos of anyone going through the motion. I purchased 2 part weld on 40 and a triangular acrylic rod to put in the seam but I don’t want to go in blind. The tank does not leak but does have a questionable looking seam that I’d like to reinforce for comfort. Is it as simple as applying the the Weldon and holding the rod in place for a bit? A acrylic professional quoted me 200 bucks for labor and 250 for his 1 and a half hour of drive time. He also said he’d polish my tank for a grand. This is a 375 gallon tank, 96x30x30. I’d also like to see some pictures if anyone else has done this to see what I’ll be looking at aesthetically.

Thanks
 

Oughtsix

Dovii
MFK Member
Apr 9, 2011
1,346
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Redmond, OR
If it were me I would balance the empty aquarium on a 45 degree angle using some wood to support it. Clean the tank and rod really well with alcohol. Tape the side / bottom of the tank to protect from any spillage. Use stick pins to keep the rod up off the corner a bit. Apply the weldon 40. Wait 2 minutes. Pull the stick pins. Press the rod down firmly. Use some books or other weight to keep presure on the rod for a couple hours. Then move onto the next seam.

If the rod is too smooth and clear I would consider rouging up the contact sides with 3000 grit sand paper.

Just my best guess.

$1000 seems excessive for a polish... but having polished a tank I know it is a ton of work and takes many hours... depending on its original condition. ~$100 an hour for driving???? Hmmm...
 
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rocco1100

Candiru
MFK Member
Dec 11, 2011
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91107
Which seam are you reinforcing and how much Weldon 40 did you buy? Whats the thickness of the triangular rod? Whats the thickness of the acrylic on your tank?

With some advice from Wednesday13, I just helped a friend reinforce 9 seams on his 96x36x30. We did the pour method on the seams. If the seam you want to reinforce is small enough or you purchased enough Weldon 40, I would recommend the pour method
 
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TheWolfman

Giant Snakehead
MFK Member
Sep 5, 2010
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I just polished my 450 and it was a ton of work. I would say I have close to 40 hours invested, with wet sanding and buffing. $1000 seams high for a polish but if you asked me to do it I’d probably say the same.
 

Bigofishys

Gambusia
Original poster
MFK Member
Dec 8, 2014
16
12
8
Sacramento
Front left side seam. The acrylic tank
Which seam are you reinforcing and how much Weldon 40 did you buy? Whats the thickness of the triangular rod? Whats the thickness of the acrylic on your tank?

With some advice from Wednesday13, I just helped a friend reinforce 9 seams on his 96x36x30. We did the pour method on the seams. If the seam you want to reinforce is small enough or you purchased enough Weldon 40, I would recommend the pour method
The acrylic on the tank is 3/4ths of an inch. The triangular rod is 3/4ths of an inch as well. I’m thinking of taking it back and getting a square rod instead. As far as the weld on 40 I only purchased a pint. This is the front left side seam. In regard to the pour method I would need to hoist the tank at an angle like oughtsix suggested right? I won’t have much help.
 

rocco1100

Candiru
MFK Member
Dec 11, 2011
105
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91107
Yes you would just need 3 people total to move and tilt the tank in place. It's not as difficult as you would imagine.

Even if you decide to use the rod, I still recommend tilting the tank so the seam is parallel to the floor
 
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JA-MD

Feeder Fish
Mar 11, 2020
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4
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48
I have a question somewhat along the same line . I am looking to purchase a previously built in custom aquarium and then installing it in my home. The tank is acrylic and about 10 years old. It is an L shape, 9 feet on the long side of the L and 6 foot on the short. It is about 400 gallons. It is currently installed and not leaking. I am sure that moving it is going to be hard on the tank and that prior to re-installing it, it would be a good idea to reinforce the seams. Does anyone have any recommendations on the best way to do that? Some of the earlier threads talked about a tilt method and weldon 40. Due to the shape I have serious concerns about trying to tilt this tank. Seems like it would be to unbalanced and might stress the seams even more. I have been very fortunate in my fish keeping in that I have never had to deal with a leaky seam so this is very new territory for me. I would appreciate any wisdom anyone has to offer. I'm going to go knock on wood now :)
 

Oughtsix

Dovii
MFK Member
Apr 9, 2011
1,346
344
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Redmond, OR
If you do not see any air gaps in any of the Acrylic seams I would just run it without adding any reinforcement.

If you do want to reinforce the seams you should be OK with tilting the aquarium. The aquarium should be plenty strong enough to be stood up on an angle when it is empty. Make sure the seam the Aquarium is resting on is supported pretty evenly the full length of the seam. A piece of Styrofoam or other closed cell foam under the seam the aquarium is resting on will help level out any pressure points. Make sure the part that is in the air is secure. For an L shaped aquarium you will probably want to support the part that is in the air at at least 2 points.

What type of stand do you have for the tank? standing an L shaped aquarium on the short seam of the tank will be interesting. For this I would consider strapping the tank to the stand then tilting the entire stand if you have a solidly built metal stand.

A solid level stand is your best defense against springing leaks in acrylic seams. If the tank is supported evenly over the entire bottom there should be no hot points (extreme pressure points) which are what usually cause leaking problems. Putting closed cell foam under the entire bottom of the tank is a good way to equalize the forces from the weight of the tank just like using closed cell foam described above is a good way to equalize the pressure on a single seam when the tank is tilted.

P.S. Welcome aboard!
 
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