Leaking master bathroom sink drain at wall - advice sought about repair

[aloharobbo]

I just acquired a condominium apartment in generally good condition, but one of the inspector's callouts was a leaky drain connection on a bathroom sink. There is definitely slight water damage underneath the connection to the drain stem in the wall.

I unscrewed the PVC connector, and found a lot of copper corrosion on the threads. The previous owner completely refurbished the apartment in 2020, but it appears that maybe this particular bathroom was the last room done and the absentee owner didn't care/know that this drain pipe connection was bad.

The interior plumbing is all new, and I'm surprised the drain stem wasn't prepped for the new connection - but it clearly wasn't.

Pros/experts - what is the best way to clean these mineralized threads and reattach the PVC connector without leaks?

 

[TomFOhio]

You can take a razor knife or something sharp and chase out the threads. Replace the gasket with a new one and then re pipe dope the
threads and then tighten it all back up.

 

[Twowaxhack]

Hit it lightly with a wire brush to clean it up.

 

[aloharobbo]

Thanks to all for the advice - I used vinegar on the mineral buildup, the wire brush and razor blade to clean up the threads, and some teflon tape. The combination worked perfectly!