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More questions about pinhole leaks in copper pipe

We've found a few pinhole leaks in copper pipe in a 60 year old house. I've read the threads about this problem and have a couple of other questions for the plumbing experts in the group:

1- I read that excess flux when soldering copper pipe has been implicated in causing pinhole leaks. How long does it take for a blob of acidic flux that has settled into the pipe to erode the copper and cause a leak? It it years...or is it just weeks to months? :confused:

2- I don't want to replumb just yet....is there any kind of sleeve or patch that can be applied over the copper pipe to stop the leak? Honestly, the leak is VERY slow...only a few drops per day. It seems to me that a rubber sleeve and a hose clamp would completely stop the leak.....any suggestions?? :confused:

Thanks in advance for the advice!

Re: More questions about pinhole leaks in copper pipe

I don't think you could say exactly how long it would take for the leak to develop. The water quality (local pH, well vs. public) and the quality of the copper pipe (different wall thicknesses are available) will affect the length of time.

I am not sure how effective the rubber patch would be. It would probably work for a while. I had a similar situation when we bought this house. I planned on re-plumbing completely, but had a few pin holes to take care of ahead of the intended schedule. I simply cut the pipe out around the pinhole and installed a compression fitting ball valve. It fixed the leak and I had an extra valve in place to help isolate the water lines as I worked on the re-plumbing later. I was able to use the valves other places later.

Re: More questions about pinhole leaks in copper pipe

Not a plumbing expert, but I agree with bp21901 about the length of time.

If you use a rubber patch and a hose clamp it will work. Had the same situation once with a nail hole in a copper pipe, solid stream. Had other projects going and needed a quick fix until I could get to it. I wrapped rubber patch around pipe and installed hose clamp. I know it worked for over a year because quite frankly I forgot about it until I did some re-plumbing. Be sure to wrap the rubber completely around the pipe so the clamp doesn't make direct contact with the copper.

Re: More questions about pinhole leaks in copper pipe

The rubber patch may work. I've had limited success doing that. What I've done usually is cut out a section of tubing on either side of the pinhole, maybe 4" to 6" & just replace the tubing. No need to re-plumb necessarily.
It gives you a chance to hone your copper soldering skills. The hardest part is trying to get all the water out of the line. One trick is to insert cotton clothesline into the tubing to help soak up the water. If you need direction about soldering just ask or try the TOH website. Basically get it clean with emery cloth and brush, use plenty of flux, but don't get carried away & heat the joint with the torch right against it almost and let the solder flow into the joint. Don't heat the solder thinking it will flow into the joint.
Cut the removed tubing at the pinhole to check it out. My water is acidic, but it often looks like the copper had an existing flaw in it at the hole. Not like the entire inside is eroding away. If you have 60 years out of your copper, you are doing a lot better than my 25 year old stuff.

Re: More questions about pinhole leaks in copper pipe

Thanks for the answers.....

I'm in exactly the same situation as jlmcdaniel....I'm planning to redo the plumbing eventually, but right now I'm looking for a quick fix just so that I can get on with other things and then get to the plumbing when the time is right and I have all my ducks in a row.

I'll try the rubber patch with a hose clamp. If it does not work then it is easy to proceed to a more extravagant fix. I mean, the pipe is 60 years old so it does not owe us anything. The sections I have removed reveal that the pipe is pretty thin walled....no wonder there are leaks, and (like mice) there is never just one.

Thanks for your input. :)

Re: More questions about pinhole leaks in copper pipe

You can hold back the water by balling up white bread and stuffing it in the lines. It will hold long enough to solder up the pipe. Once the patch is done, turn on the water. Remove aerators from faucets and flush the lines. The pressure & the water will dissolve the bread and flush it out.

Do NOT use wheat or whole grain bread or even crusts. That stuff won't break down like white bread will, and could plug your faucets.

You can also buy gel capsules specifically for this purpose. The gel dissolves in water. But bread is a lot of cheaper!

Re: More questions about pinhole leaks in copper pipe

Or .... you can drain the line by opening a tap at the lowest point in the home. If you have a washer or tub in the basement open that tap along with a tap at the furthest point to drain the line.

Re: More questions about pinhole leaks in copper pipe
canuk wrote:

...you can drain the line by opening a tap at the lowest point in the home...

Of course you should do this, I just assumed that was a given. And you know what they say about "assume"...

Even so, I'd venture to guess that most plumbers don't bother sloping the supply lines to a low point. If you drain the system as much as you can, chances are good that the pipe you are working on will slowly drip water anyway. Since any water in the pipe will prevent it from heating up enough to properly melt the solder, be prepared to use the bread trick.

Be sure to open up all the faucets when you're repairing the pipe. Steam pressure buildup can injure you or mess up your joint before the solder cools, so having the faucets open will prevent that. And please wear safety glasses. Molten solder in the eye is NOT FUN.

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