Need help on new vanity install, metal to PVC help needed

[Hammerlane]

You cleaned the wazoo out of them threads. Look brand new.

Post photos after you get in the male adaptor----> short length of PVC------->trap adaptor

 

[Jadnashua]

The threads provide the mechanical connection, but to seal, the tapered threads need to tighten up and not bottom out first, with all of the gaps filled with the sealant (pipe dope and/or teflon tape). So, make sure it is getting tight because of the taper, and not because it bottomed out where it in theory anyway could still move. You can adjust the thickness of the seal and when it engages by putting another wrap or two of teflon tape over the male piece you screw in.