That guy at the hardware store told me to stop mixing copper and galvanized pipes

He was this old electrician buying conduit, not even a plumber, but he saw my cart and said I'd get electrolysis corrosion in under 2 years. Sure enough, my neighbor ignored the same advice and had a pinhole leak in his basement ceiling after 18 months. Has anyone else had bad luck mixing metals in their home plumbing?

3 comments

3 Comments

david_palmer4d agoMost Upvoted

Wait, is this the same stuff that happens with old aluminum wiring in houses where the terminals literally start falling apart from galvanic corrosion?

the_mary4d ago

2008 is when the NEC finally forced the industry to admit aluminum wiring wasn't the boogeyman everyone made it out to be. The original issue was never the aluminum itself, it was the wrong connectors and lack of proper torque specs during installation. But @david_palmer, people still repeat that 1970s panic about aluminum like it's gospel truth. Copper tarnishes way faster than aluminum in my experience, and aluminum's corrosion is actually self-limiting because the oxide layer stops reacting further. The real problem in those old houses was that they mixed copper and aluminum on the same circuit without using those special Alumiconn connectors, which creates exactly the galvanic mess you're describing. If everything was properly rated and installed per modern code, aluminum is totally fine for house wiring.

the_drew4d ago

Wait, so the industry admitted aluminum was always fine? @david_palmer I didn't realize they actually forced that change in 2008, I thought the panic was still the official line.