joining copper pipes with a water trickle

The copper pipe that feeds the garden tap has started to leak - not sure if it's the cold weather or just old age. On investigation it appears to be the compression joint where the pipe exits from under the patio through a brick wall, to join an up-pipe to the tap itself. I can get access to about 10cm of the pipe (it's 15mm diameter), as I've drilled out the bricks adjacent to it, however the rest is just too deep under the patio to get to.

The pipe itself seems to be pitted, which might be why the compresion joint is leaking. I'd like to replace it with a soldered joint, but the seepage of water (as the house main doesn't turn the water off completely - there's still a slight trickle) would take all the heat out of the joint before the solder melted. I can't get access to any part of this pipe from the stop-c*ck to where it exits the patio wall - so freezing it is not possible.

Any thoughts, or techniques for fixing the leaky joint, preferably with something other than a compression fitting (because of the pitting) would be appreciated.

Reply to
pete
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I suggest:

As well as turning off the water see if you can open a cold tap that is lower than your joint, or perhaps the drain point of the system. so the trickle goes out of that instead.

Bung a bit of bread up the pipe. With luck, this will soak up the trickle for long enough for you to solder the joint and it flushes out harmlessly when you open the tap.

R
Reply to
RobertL

What you need is something you can shove up the pipe that will block the water for as long as it takes to make the repair - and then disappear. Bread has been suggested before - it should eventually break down once the water is turned on again - but you might also consider some sort of soluble tablet. Otherwise, a big nozzle on a gas gun.

Regards,

Reply to
Stephen Howard

I'd just redo the compression joint with a good slathering of your favourite glop on it. I use ordinary silicone sealant but each to their own. Soldering an already corroded pipe, especially with the water trickle problem, is unlikely to be a better choice. Silicone, provided you give it time to set before it sees any water pressure, is pretty much bulletproof IME. For that reason leave the tap open for a few hours with the mains off while the silicone sets. Leaving the cold tap in the kitchen sink open should minimise the water trickle to the garden pipe.

Of course once you get the joint apart you might actually find it's a split in the pipe caused by freezing and nothing to do with the corrosion at all.

Reply to
Dave Baker

Why not replace the mains tap while you're at it: or can't you get at the supply tap in the road?

I used to have trouble getting at and turning off our mains tap - where someone had helpfully put the bath in front of it! Eventually, when I went to turn off it on one night after fitting a new loo ballcock, the whole thing broke off at the wall: nothing like a midnight flood to inspire one to get the plumbing right! (You never saw a bath ripped out so fast!)

S
Reply to
Spamlet

Suggest you try to put in some sort of valve between your house stopcock and the garden tap - if not now, then in the summer. (Yes - I did read what you said but surely there must be at least some possibility of doing this?) Ability to turn it off might have avoided a problem now and would certainly assist with fixing it.

Reply to
Rod

I'd wrap it in self-amalgamating tape, with a layer or two of fabric reinforced tape over the top for pressure resistance.

Colin Bignell

Reply to
nightjar

I think that might still leak (although I have actually used ordinary "electrical" pvc which worked on a tiny leak for a while).

Provided you can get enough clearance to wrap tape around it under some tension, there's a silicone self amalgamating tape called ilfatape

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which radiospares stock. They were giving away dvds with an impressive demonstration last time I was at a trade counter. But havn't tried it myself.

You might also consider one of those plumbers' "repair" epoxies, I have used them successfully long term on really awkward leaks like behind a hot water cylinder.

Reply to
newshound

(To you and spamlet). I'm planning to put an isolating valve on the garden end of the pipe when I come to do the work. I realise these only come in compression[1] fittings, but on a clean pipe without pitting where the olive goes, it should hold. So far as changing the tap (stop-c*ck?) goes, or putting an isolator on at the "house" end, it's definitely a no-no. The stop-c*ck is in a corner of the kitchen, at the back of a (large & oddly shaped) cabinet. it was renewed ~9 years ago when I had a new kitchen, but to replace it now - or to add an isolator to the garden pipe would involve ripping out a large part of the kitchen. It would be easier and less stressful to move house.

[1] I absolutely hate compression fittings. Even more for outside use. The changes in temperature means they expand/contract throughout the year so the seal may start off "perfect" but degrades over time. They also seem to me to be a kludge. Call me old-fashioned, but I prefer metal to metal bonded joints over a screwed-up nut that could work loose.
Reply to
pete

There is an alternative. Last outdoor tap I fitted has (mostly) plastic pipe and fittings - but not tap!

Reply to
Rod

Yes, I've checked the John Guest (Speedfit) website. The drawback is that their (quite impressive) product range and installation guide warns against using their fittings on scored or damaged pipe. (Plus, they seem to be a b@s***d to get off once fitted, if there is a leak) I'm saving that as the method of last resort.

Reply to
pete

Sorry - should have been clearer - I was meaning for the full replacement project! I think it entirely a matter of luck whether one would work at the moment.

Hep2O at least is quite easy to dismantle (not the slim sort) using the special tool (just a little plastic thing).

Reply to
Rod

Use the existing compression fitting (with a new olive and pipe sleeeve) onto a new length of plastic pipe to the tap.

I suspect the original leak was caused by the olive moving on the copper pipe due to the pressure of the water freezing back from the tap.

Reply to
<me9

Never has when I've done it in the past.

Colin Bignell

Reply to
nightjar

I had similar problem once, couldn't completely stop mains water due to leaking valve, but leaked enough water to stop soldering on a leaking joint under a kitchen unit.

Solution was to connect a wet/dry vacuum to another part of the pipe work. This kept the water at bay enabling the damaged joint to be removed (crinkled/bent pipe next to a compression elbow) and replacement pipe and elbow soldered in.

Eventually properly sorted by attaching a full bore lever valve above the mains stop c*ck so water could be properly isolated.

Reply to
Ian_m

Veeeery clever. I might just give that a try (as I can test it without doing anything irreversible to the existing setup).

Reply to
pete

You sir are a solid-gold, 5 star GENIUS. I did this today: using Duck tape to hold the nozzle from the wet'n'dry vac. to the kitchen tap. Turned the water main off, opened the kitchen tap & fired up the vacuum. Perfect results, it sucked all the water away from the seeping exterior pipe long enough for me to whip off the old compression joint, clean, flux, tin and apply a proper soldered 90-degree elbow. On inspection, the reason the original joint failed was due gross pitting and scarring on the outside of the pipe. There were more craters than on the moon, and no possibility that a new olive would've sealed the holes. There was also remnants of PTFE tape, bathroom sealant and some other substances (that I prefer nnot to think about) that the bodgit guy who had the house before me had obviously tried to "fix" the problem with.

You have my complete permission to take the rest of the day off. Put your feet up, eat bacon butties and drink beer.

Reply to
pete

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