Jadnashua
Retired Defense Industry Engineer xxx
If your pipes were not bonded properly to ground, or if there was an electrical fault somewhere in your home, if you removed that bonding cable, then measured voltage between the pipe and that ground point, you might find you have a significant voltage there. If there's voltage, there's probably current, and when you have dissimilar metals and an electrolyte (water that is not distilled), you can get the effects of a battery, and corrosion.
That Maryland test report only discussed excessive acidic flux as a possible installation error. Others have reported the issue I mentioned about turbulence creating cavitation. You can read about cavitation and its effects on things like propeller blades on boats, pumps, etc...that can and does cause erosion of the metals at certain flow rates.
Bottom line, there may be more than one thing that leads to pinhole leaks. The location of them can help narrow down the possibilities. In random locations, not near any fittings, it's probably either a defect or chemical. Downstream and near a fitting, it may be mechanical caused by assembly error, or excessive use of flux. FWIW, acidic fluxes are no longer used from what I see, and the new ones are a bit harder to use, but that's a different story. I think acidic fluxes were still in use when your house was built. Normally, it isn't an issue, but that assumes good workmanship, but also, how long things sat before regular flow was introduced that could flush things out.
That Maryland test report only discussed excessive acidic flux as a possible installation error. Others have reported the issue I mentioned about turbulence creating cavitation. You can read about cavitation and its effects on things like propeller blades on boats, pumps, etc...that can and does cause erosion of the metals at certain flow rates.
Bottom line, there may be more than one thing that leads to pinhole leaks. The location of them can help narrow down the possibilities. In random locations, not near any fittings, it's probably either a defect or chemical. Downstream and near a fitting, it may be mechanical caused by assembly error, or excessive use of flux. FWIW, acidic fluxes are no longer used from what I see, and the new ones are a bit harder to use, but that's a different story. I think acidic fluxes were still in use when your house was built. Normally, it isn't an issue, but that assumes good workmanship, but also, how long things sat before regular flow was introduced that could flush things out.
