Finally got a solid bond on some old knob and tube at a 1920s house in Portland

I was working on a rewire in this old Craftsman last week and the cloth wiring was so brittle I thought I'd never get a good connection. Tried tinning the ends with rosin core solder before putting on wire nuts, and it held like a champ after testing. Learned that old copper can be tricky but a little prep makes all the difference. Anyone else have tricks for dealing with ancient wiring?

3 comments

3 Comments

eva_thompson1mo ago

Wait didn't I see a sparky on another forum say tinning can make the wire brittle over time with heat cycles? Might be worth looking into how that holds up long term.

lopez.quinn1mo ago

Tinning old knob and tube sounds like asking for a fire with extra steps.

faith_thomas1mo ago

Yeah @eva_thompson is right, I've seen tinning make old wires crack after a few years too, it's a disaster waiting to happen.