Hello,,,,I have the following issuessquestion
1) I have an ever slow slow weep if you want to call it that at the connection to the sink. I tightened up on the nut holding the large black tapered gasket. How tight should this be? I cranked down on it and the leak slowed from a drip that would bleed through to something less than that. When you rub your fingers around the threaded collar you get water on your fingers. Should I leave alone....will it stop eventually as calcium and minerals stop it?

2) I transitioned from chrome to a PVC 1-1/4" extension to get to the 1-1/2" P trap also PVC. I than connected the PVC to a 1-1/2" male copper threaded fitting at the wall. The hardware store gave me pvc collar for this. I had a small leak here, a slow drip every so often. I think what he gave me was for PVC to PVC. Should I be using the flat rubber washer here in leiu of the PVC collar? The PVC fitting has an integrated washer type set up. But my copper fitting has a flat front which seems to accommodate those flat rubber washers.