Slow Leak Below Sink Drain

[DC Newbie]

In the process of installing the bathroom sink drain and p-trap I posted about earlier, and ran into an issue with a slow drip that occurs between the silicone washer and brass nut underneath the sink drain. I have tightened the heck out of it, to the point where I'm concerned that I could crack the sink, so I don't think that's the issue.. The top part of the drain came with another, thinner, silicone washer, and my thought was to place a line of plumber's putty between this upper washer and the sink basin. Any other ideas?

 

[Terry]

The leak doesn't come from the upper flange. It finds it's way around the threads where it passes through the drain hole in the bowl.
Pull the drain out, and either rub putty on those threads, or pipe dope. Then drop it back down, push the large rubber washer back, and thread the large lower nut up snug.
Plumbes as a matter of course do it that way. You will never find the instruction in the paper work though.

 

[Sponsor]

 

[DC Newbie]

The leak doesn't come from the upper flange. It finds it's way around the threads where it passes through the drain hole in the bowl.
Pull the drain out, and either rub putty on those threads, or pipe dope. Then drop it back down, push the large rubber washer back, and thread the large lower nut up snug.
Plumbes as a matter of course do it that way. You will never find the instruction in the paper work though.

Thanks Terry, that did the trick!

 

[DC Newbie]

Dangit, I just realized I forgot to put a bead of silicone between the vanity top and the vanity itself, before I secured the drain...guess I need to undo my work.

 

[Cacher_Chick]

I would not remove the sink drain to mount the top. Taking the trap off and leave the drain assy in place will make the job quicker and easier. Just be careful not to damage the drain while you are moving the top.