Acrylic External Overflow Leak Help

[tchristman]

I moved my frag tank downstairs to the basement. It has been sitting for a few weeks and yesterday I plumbed the new sump, pump and such.

When I got it running everything was great until I noticed a small leak out of the corner of the external overflow mid-way up the overflow.

I took the drain plumbing out of the overflow and can run everything without the drain pipes since the return pump is not overly powerful and there is a small amount of flow through the overflow. This lowered the water to next to nothing in the overflow and eliminated the leak.

I am not familiar with doing acrylic work or repairs and my questions pertain to resealing the internal edge of the external overflow. As long as the water level stays low it will never be a problem but I would like to seal the leak. How would I do this? Would a bead of Weld-On work? Can I just use silicone? I know silicone does not adhere great but it is not a high pressure area and it is only being used to seal not strengthen.

Your input is appreciated. Thank you..

 

[jj ocean]

Without seeing it, hard to give exact recommendation. However, one thing for sure is dont use silicone to fix it. Most likely get the thicker Weldon (16 i believe - going from memory) and run a good bead on the inside of the seam. Keep your flow down for 24 hours until it cures. And then put back to normal and check for leak.

 

[tchristman]

So the Weld-On will provide a bead? If so, that is perfect. It will act the same as if you were applying silicone to a glass piece? I am not familiar with working with Weld-On.


Thanks.

Edit: So the Weld-On will provide a bead similar to what silicone would do? If that is the case than that is perfect. It is a very small leak but still a leak.

I guess I could also glue a corner piece of acrylic as well.

 

[jj ocean]

You need to get the thicker Weldon and it will produce somewhat of a bead. Close to elmers glue consistency It will run down some though. Not thick like silicone, but a decent bead. Since it is on the inside I would use a liberal amount since you won't see it. No need to worry about cosmetics.

 

[wbrown]

weld-on instructions state 7 day cure. I'm certain that it refers to a structural seam, but you might want to wait to assure out-gassing is complete.
McMaster-Carr stocks weld-on btw.

 

[jj ocean]

If you can wait 7 days sure. Your right - structural strength is a completely different animal Most of the guys that have done seam and sump repairs only wait a couple hours. I added full matrix baffles a couple months ago in sump with 12 hour cure and zero ill affects. Something like a small leak in the seam should be no issue.

 

[grouper therapy]

I would try the thin stuff first and place a clamp on it. Before trying the 16 thick stuff not a fan of it as it shrinks too much. I'm building some sumps next week if you want to bring it up I will fix it for you.

 

[tchristman]

Thanks for the suggestions. Thanks Dave. The tank has water in it and it only would be a problem if I run my overflow more than half full of water. Since the pump running the return is not a high flow pump I am fine. I can actually repair it and let it keep running since no water will get that high. I am going to try the thin stuff first and if does not create a seal I will try the 16. Thank you all.

Tim