Learned the hard way about aluminum wiring on a reno last Tuesday

I was rewiring a old house in Oak Park, built in 1968, and found aluminum branch circuits everywhere. Figured I could just pigtail with copper and use regular wire nuts like I always do. First junction box I opened, the connection felt loose and the wire was all corroded and brittle. Called my supplier and they told me I needed special antioxidant paste and rated connectors. It added 3 hours to the job and $45 in parts I didn't plan for. Has anyone else dealt with aluminum wiring surprises on a remodel?

3 comments

3 Comments

wilson.kelly7d ago

@king.wyatt mentioned the purple wire nuts and paste, but what about the junction boxes themselves? Were you able to reuse the old steel boxes, or did the inspectors make you swap them out for plastic ones rated for aluminum? I found that the old boxes sometimes get corrosion inside that the paste won't fix, so I ended up replacing the whole works on one floor. Did you run into that situation in that split level you mentioned?

king.wyatt8d ago

Yeah, that antioxidant paste is no joke. I had a similar rude awakening on a house from the 70s where I just assumed I could use the same old nuts. The corrosion is the real killer, it creates resistance and heat which just makes everything worse. You gotta use those purple wire nuts that are specifically rated for aluminum to copper connections, they're like the only safe way to do it without a professional crimp tool. The paste is a must too because it keeps oxygen off the aluminum and stops that white powdery gunk from forming. It's frustrating because the inspectors in my area are getting strict about it too, they check every single box now if they even suspect aluminum was used originally. Definitely a lesson nobody forgets after they've had to redo a whole floor's worth of junctions.

nathanj568d ago

Purple wire nuts and the paste are the only way to go once you find that white powdery corrosion. Had the same thing happen on a '69 split level and it turned a two hour job into a full afternoon. Inspectors around here are hammering down on it too, they flag anything that doesn't have the rated connectors now.