SpudFiles

DUCT TAPE.
The mythbusters made a dang sail boat out of it, I'm here to tell you it is water proof. They also patched a hole in the side of a boat and it held in the water for an hour. If it can patch a boat, it can patch a fish pond.

Gippeto wrote:Aquarium silicone. Check at a bigger pet store.

Clean the area with paint thinner or similar degreaser, then sand it to rough it a bit...use coarse paper...40grit.

Spread the silicone about 2" on either side of the crack, and the same out from the ends of the crack.

Take a piece of fibreglass screen the size of your spread out silicone, and work it into the silicone.

Cover with more silicone, (max total thickness 1/4") let cure 24hrs.

I've patched plastic tanks on radiators using this technique, if it holds for years at 16psi, it'll work on your pond too.

I agree with Gippeto on this one

this would be the best way to fix it in my opinion

If you want to have it seal and never have a chance to leak, just use heat to form a new bond in the actual material.

Take a propane torch to it, melt in some polyethylene over the crack. it will be quick and easy. gluing is going to get tricky and messy.

If you want to go the welding route, here's a good site to check out:

http://plasticweldingandtools.com/

But I still say to use silicone to repair it. Gipetto's method seemed to be the best I've read so far. Fish tank silicone would work, I will not deny it, but I still suggest window weld above that for a couple of reasons:

It's black, not clear

It will bond better, and will make for a stronger repair.

It's definitely just as water tight of a seal.

And aquarium silicone is more of a sealer, window weld is a bonding agent made from urethane, which will be more durable. it's regular purpose is for adhering glass windshields into cars, so it will definitely adhere to your plastic tub.

Check the info here:
http://solutions.3m.com/wps/portal/3M/e ... NCGJPCKHbl

Thanks it is high densite polyetylene, Im gonna either cut a bit from the lip of the pond or a 5 gallon bucket and use a propane torch

clemsonguy1125 wrote:Thanks it is high densite polyetylene, Im gonna either cut a bit from the lip of the pond or a 5 gallon bucket and use a propane torch

Good luck with that...take pictures.

clemsonguy1125 wrote:and use a propane torch

Nooo! epoxy and a patch (even a bit of cloth will do) applied to a properly roughened surface will do the trick, without the risk of setting it on fire

Spoil sport...

FINE! I'll post a pic myself!

It was roughend up and cleaned properly. From what I have read epoxy does not bond to HPDE.
EDIT-I just ordered a cheap plastic welding iron from harbor freight. It has a reviews saying it was used to fix a plastic fish pond.

they do sell marine epoxy/putty.

when using the propane torch, set it to low and sweep over the crack as if you were spray painting for a total of about 5 seconds, then heat the rod and push it through.

Thanks, I just ordered a plastic welder though.

I see that you have decided to weld it.

Plumbers Goop would have worked, though. It WILL stick to that plastic, if the plastic is roughed up a bit with sandpaper.

Sand the area well. Clean with alcohol. Let dry completely. Then use the goop.