CH joint leak

[BartC]

I have a slow leak from a joint in a CH pipe (about one drop every minute or two).

I tried Plumber's Mait (a cheap version a few months ago, the real thing just now), it still leaks!

Any other easy options to do a quick fix? (Ie. without draining down everything and replacing or resoldering the joint). Or haven't I used the Plumber's Mait properly?

(The joint, a solder-ring 15mm equal tee, is in a very awkward place: inside a cupboard, with one branch disappearing immediately into a wall, another into a door-frame, and there's a parallel pipe right next to it; it's the remaining branch that leaks.)

[Mr Pounder]

Plumbers Mait cannot stop the leak from a soldered joint. A plumber once tried to stop a drip in my old house with some "special" paste. It did not work. The pipes can be frozen and the joint made good. If it is that difficult to get at, ring a plumber.

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[The Natural Philosopher]

if you can isolate it try car body filler.

I did a temp repair once by wrapping the thing entirely in PTFE tape..it turned a gush into the occasional drip

So bit of tape and then smother it with car body filler MAY stop the leak.

It is a frightful bodge of course.

[harry]

You might be able to make a repair with a bit of soft rubber sheet (or similar) and a jubilee clip. Put rubber over leak with some jollop on it,slide jubilee clip over and tighten down. May not work as there is a surface irregularity.

[John Rumm]

Alas no - its designed for helping to seal threaded connections - it has no practical use as a sealing compound on its own.

Well the proper solution would be to remake it. However you can get plumbing leak repair sticks that may fix it. These come as a strip or or bar of epoxy putty - usually about 1/2" wide in two coloured sections. You rip a bit off, and then mix the two colours together until they are fully mixed. This gives you a firm sticky blutak like compound that will stick to wet surfaces etc. Use that to patch your leak, and it hardens in about 5 mins or so.

e.g.

[Mr Pounder]

You might be able to make a repair with a bit of soft rubber sheet (or similar) and a jubilee clip. Put rubber over leak with some jollop on it,slide jubilee clip over and tighten down. May not work as there is a surface irregularity.

It would appear to be leaking from a badly soldered copper tee. Of course there is going to be a irregular surface --------------- pipe goes into fitting.

[Dave Liquorice]

Or the other epoxy based stuff designed for the purpose. I would expect a plumbing version to remain a little more flexable than CBF.

Self amalgamting tape is another possibilty, used that to hold in the stupid little easy to break air vent plug on a TD5 top radiator hose for many a month. A CH pipe shouldn't be a problem, if you can get it clean and dry and stretch the tape enough. At a push a good quality electrical insulating tape might do, but wouldn't last like SA tape.

[BartC]

Yes, that's the stuff I used ('plumber's mait quick leak repair putty - instant repair for pipes, radiators, tanks and cylinders').

There's still some left, so might try again. Otherwise I might try the rubber and jubilee clip idea; I just need some rubber, and a jubilee clip...

[newshound]

Epoxy is was what I was going to suggest; in the good old days plumbers mait was a sort of non-setting putty, never heard that term used for an epoxy. It won't normally set against mains water pressure or against a pressurised CH system but will set against the sort of pressure you have in an unvented cylinder. So one fix might be to depressurise the CH, use the epoxy and give it an hour or two to cure before repressurising. Rubber and jubilee clip will also work if the geometry is favourable; OK for a pinhole in a straight pipe run, less likely to work at a joint because of the "step".

A couple of years ago radiospares was promoting a sort of self amalgamating tape which would work on 3 bar, if you applied it correctly. (Needed a double or triple layer, IIRC). Never got around to getting any to try because my inclination would almost always be to do a "proper" repair.

But I have used epoxy a couple of times on awkward leaks, typically on hot water cylinders.

[Trevor Smith]

Why not try Fernox LSX, my hot water cylinder had a tiny pinprick hole in the top and due to the foam insulation I didn't want to solder it so i smeared LSX on the hole and it's been fine since and that was way back last April