|Posted by Paul on April 24, 1999 at 18:41:08:|
|In response to Re: Pin hole leaks in copper plumbing|
: : I recently repaired my second pin-hole leak in two years. When repairing the leaky fitting I discovered that the 3/4" copper pipe had become very thin. Both leaks occured on the main supply line between the water meter and the water softner.
: : I measured the pH of the water at 7.6 - 7.8 using a freshwater acquarium test kit. So I basically have ruled out acidic aggressive water as the culprit. I am therefore assuming that the problem is the result of electrolysis.
: : Both my electrical breaker box and phone line have ground connections to my cold water supply line. This line runs approximately 50' to the water meter which has an electrical bypass strap across it. Can my problem be due to stray current flowing through my pipe to earth ground? This grounding approach appears to be pretty common though so I am not convinced that this is the cause of my problem.
: : My house is apx. 20 yrs old and I have city supplied water.
: : Any advice would be greatly appreciated.
: You said you repaired the fitting. Were both leaks at fittings? If so and you have ruled out the water as the cause by having a professional analysis done on it, it could be the solder used to solder the fittings together. There are different types of solder and there is a special type used just for copper plumbing. They look the same sitting side by side but are very different. I would look at all of the solder joints I could see and if any of them have any kind of corrosion on them, then I bet its the wrong solder. If it was done twenty years ago its hard to say, the solder could have gotten mixed up or the plumber didn't want to spend the extra money for the right solder.
Both leaks were in 90deg fittings. One pin hole was in the copper. The other one appeared to be very close to the joint. So the latter may have been leaking through the solder joint. However, the thickness of the pipe adjacent to the fitting appears to be very thin. The solder joints that I have inspected look fine.
Tomorrow I am planning to hacksaw (and repair) my plumbing in a couple places to determine the extent of the damage. I am hoping it is localized to this particular area of plumbing.