"dadiOH" wrote in
:

gwandsh wrote:
On Dec 29, 4:45 pm, "HeyBub" wrote:
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

If you've got water that's any kind of hard, put a bucket under the
sink for a few days and see if the leak heals itself.

Thanks all for the responses. To fill in some gaps in the info:
I have already re-installed this a couple of times.
I use a pretty thick roll of plumbers putty. Perhaps tightening has
squeezed out too much.
I *did* try the finger tight nut solution. I then tried tightening a
half turn and re-testing. After 4-5 half turns, I stopped in fear of
damaging the sink.
To Red Green (one of my fav shows, BTW): If I have over-tightened
the black washer (I assume that's the "cone" washer, it does have
that shape), does it need to get replaced before I try to re-install?
Can I use some plumbers putty along with the cone washer to make the
seal on the underside of the sink?

Cheers

You don't need a seal on the underside, it should seal on the top -
inside the sink. The nut is just to pull the inside drain flange down
so the inside seal is made.

How does the overflow water get into the drain in sinks with an
overflow?

Through the holes in the side of the tailpiece pipe that sits inside the
sink. Not visible once connected. The overflow runs in a hollow sink
chamber and goes into the tailpiece holes. When the sink is draining
some water can also come out of the holes and enter the bottom of the
chamber...where the cone washer is.


Hole to the left of the white washer.
http://www.plumbingsupply.com/images...upassembly.jpg

Holes above the white washer.
http://mrdirectint.com/sinksandfauce...opup_drain.jpg

And another
http://common3.csnimages.com/lf/2/ha...h+Overflow.jpg


You are talking about the tail piece, right? The metal tube with a
flange that fits through the hole in the sink and is attached to it
with a nut? I ask because you mentioned a cone washer...never seen
one of those used in that situation. Flat, yes; cone, no. Cone
washers are used when hooking the P-trap to the tail piece.


Cone washer pretty common. Not always used I guess. Just like all sinks
don't have overflows and all popups don't provide for overflow.

http://common4.csnimages.com/lf/2/ha...h+Overflow.jpg


OP:

Does your sink bowl have an overflow hole? If so, did you use a popup
with an overflow? If you didn't, once water enters the overflow chamber
it will fill with water and just sit there. Not good.