On Tue, 29 Dec 2009 13:45:36 -0800, gwandsh wrote:

Hi all

I recently installed a new bathroom vanity, sink and faucet. I am
getting a small leak at the point where the large nut tightens the
drain assembly onto the bottom of the sink, compressing the black
washer onto the bottom of the sink drain.

Was the drain pipework supplied with the sink? If not*, are you sure
there's nothing stopping the nut from tightening further, other than the
sink itself? It's just a stray thought, but I'm not sure if anyone's
mentioned that possibilty yet...

* or even if so; maybe there's damage to the threads on the part that the
nut screws on to, so it feels tight before it really is.

cheers

Jules