Ken wrote in
:

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.

I have seen sink installs before, checked the net for hints, and even
did a couple quite some time ago. I double checked the sink/vanity
that was removed from the space, and also on line, so I know the
washers on the drain assembly are in the right order. The drain
flange has a good ring of plumbers putty under it.

The sink itself is an ornamental handpainted model, and may have some
slight irregularities at the sink drain. Because the sink is
somewhat more delicate than the standard white porcelain models, I
don't want to risk overtightening the nut.

So what I am hoping to get are pointers on what the plumber-savvy
folks would do to handle a leak on the underside of the sink drain?
Can I add a thin bead of plumbers putty where the black washer meets
the sink, in an attempt to fill any irregularities the washer can't
handle? I am reluctant to use silicone at that point, just in case
it isn't successful and I have to dismantle it again.

Thanks for any tips


Drain pipes have been a problem for me as well. What I have
found is
that you need to tighten the connections as little as possible at
first.
If they leak, then tighten them some more. Over tightening them
does
not stop a leak like working with steel pipe.


EXACTLY what he said!

If you've already cranked down a lot on the nut and compressed the cone
washer then consider it shot even if it looks OK.

That large nut under the sink should be tightened as snug as you can by
HAND. If it leaks then tighten with pliers/whatever ONLY 1/6 turn (a flat
on the nut). Check for leaks and repeat if necessary. Should not take a
whole bunch more after that. If it does then there is something wrong
with the surface where the cone washer meets the sink. Once I feel it's
not leaking I fill the sink to the top and let it rip.

Plumbers putty is only suppose to be put on the top between the recess of
the sink hole where the drain flange sits.

Any chance you overtightened it already?

You would really have to overtighten the heck out of it to compress that
rubber cone washer enough to crack the sink.

It does have a CONE washer?