Repair 'putty' for PVC pipe - is there such a thing?

Oct 14, 2018 15 Replies

I have a tiny drip leak in a rather inaccessible PVC (or ABS, solvent weld anyway) pipe. Removing and replacing is well nigh impossible without knocking half of the house down. It's a solvent weld joint that isn't quite perfect. I can get my fingers to it, just, but not much else.



It's quite difficult to make it dry though that *might* be possible if I have to.



Is there any sort of repair gunge/glue/putty that I can use to mend it? I can (as I said) just get my fingers to it so I could smear blobs of 'stuff' onto it. Ideally it should work on damp pipe but if I really have to I could drain it and attempt to dry it before trying to fix it.



It's not under (much) pressure, but it does have water in it all the time (hence the drip).


Smear a little solvent cement around the joint with a (butyl?) gloved finger and mould the melted plastic around the leak?

Could you use a puncture repair kit? Seriously. A little round patch?

Bill

epoxy works on abs. Pick the soft tacky stuff for best adhesion. Or you could dissolve some of the plastic in a solvent.

NT

I was going to say that. And the special "plumbers" stuff that comes in a single stick certainly works well in wet surfaces. Rather to my surprise it even worked on a very small pinhole at the bottom of a DHW cylinder, with about five feet of head.

Best to use "surgeon's" gloves, but if you are not too fussy you can even use fingers safely provided you wash well with soap and water straight afterwards.

I have never thought to try "araldite" on a wet surface though.

Sugru should work and easy to apply with a finger in that situation.

Probably won't stick to wet pipe, though?

The other thing I have done successfully on waste pipes is to bind around a leak site with ordinary PVC electrical tape. Put the tape on under tension and spiral wrap with a 50% overlap. This may not work in your case, though, if the pipe runs tight to a wall and you cannot pull it away far enough to pass the tape reel round the back. You can make an almost invisible repair like this.

I tried that on a pinhole in plastic waste. Utterly useless.

Wipe it off first! And fwiw I would never buy araldite.

NT

But it wouldn?t be hard to dry it given that it doesn?t always have water in it.

Maybe "Gorilla"? It needs water/damp to make it go off. Not quite sure how any running water/drip would affect it. If you have a wet vacuum cleaner,you could suck any water in the pipe out b y applying to the sink waste outlet?.

It takes a while to go off, and ends up with a foam (not sure if it's open or closed cell) but I can imagine a leak just washing a hole through the glue as it cures.

Self-amalgamating tape would be ideal - but difficult to apply properly in confined spaces or single-handed.

Thing is, a pipe with joins made of pvc which is inaccessible is not a good idea for the future. You do not say what it does, washing machine outflow, perhaps. Myself I'd try to come up with some way to lose that as a route for a pipe or if something major happens its going to be even worse than a slight drip and being unable to get to it is not great news. Brian

But if you need such a pipe, solvent weld is usually the best idea in terms of staying leak free, if installed properly.

I'm less sure now that the drip is actually coming from the pipe. I'm surprised if it is because I made the original joint and was pretty careful to make sure it was good because I knew it would be difficult to access if anything was wrong.

While poking around there a little while ago I found the brickwork

*above* the drip is damp so I fear I have a leaky roof in some shape or form, e.g. flashing or window not perfectly watertight. The rain we had recently was the first for a while so might be just showing up some shrinking/cracking seals somewhere.

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