How to repair a cracked sump?

[alm502]

I have an acrylic sump that is cracked in the bottom and along a seam. Can that just be sealed with something like Weld-On or do I need something else to fill and seal them? There are no pieces missing, just cracked.

Which Weld On would I use, #4 or #16, or something else?

Thanks!

[uncleof6]

I have an acrylic sump that is cracked in the bottom and along a seam. Can that just be sealed with something like Weld-On or do I need something else to fill and seal them? There are no pieces missing, just cracked.

Which Weld On would I use, #4 or #16, or something else?

Thanks!


Since the tank has had water in it, the acrylic has absorbed water. If you try to use weld-on, the acrylic is going to craze up (minute stress factures,) and most likely will ultimately fail. Of course, silicone is unsuitable for bonding acrylic as well. The one you really need to speak with is James (Acrylics,) unfortunately it has been a long time since I have seen a post from him.

Between you, me and the wall, I would forget it and replace the tank. Some will recommend placing reinforcement pieces using weld-on, but you are not going to get around the crazing problem. It will just become a mess...

[1234]

I have an acrylic sump that is cracked in the bottom and along a seam. Can that just be sealed with something like Weld-On or do I need something else to fill and seal them? There are no pieces missing, just cracked.

Which Weld On would I use, #4 or #16, or something else?

Thanks!

I would dry the spot as much as possible, then use some #4 and then #16 on top of that to make a fillet. It'll craze unless you thin the #16 with acetic acid but for a sump it'll be ok. If you want a little more peace of mind you can add a small scrap acrylic to reinforce it, by pushing it into the #16 while still wet.

HTH

[tkeracer619]

If its a clean crack weldon 4 in the joint. It will wick in.

Follow with weldon 16 and like the others said put in a reinforcement if you want.

I wouldn't worry about the crazing so much because the sump is toast as it sits now. If a few $ of weldon gets you a few more years so be it.

[ArmyGreens]

Dry, clean and Dr again. That may help removes particles around the area and if lucky what may have ran through the crack too. If you can see any bubble or mirrored lines in the glued crack then most likely will leak again.

You can use another scrape piece of acrylic that's larger than the crack and weld that over. doesn't always work out as planned unless you used to using the needles on the bottle to wick in as mentioned above