DIYbanter - View Single Post - Bathroom sink leak -- but an unusual case!

wrote:

I recently installed a bathroom sink/vanity.
The problem is with the drain.
There was a small defect in the porcelain -- the
hole on the underside/bottom of the sink wasn't
perfectly circular, but had a small chip in it.
So when I put the gasket+washer+nut on from the
bottom, the gasket wasn't big enough to cover
the hole (because of the chip).
Silicone caulk around the perimeter worked for
a few days, but then lots of water on the floor.
What to do?
I'm not removing/returning the sink!
Do I remove the tailpiece, etc. and try to repair
the porcelain? If so, with what?
Do I try to find a bigger gasket?
Do I use some kind of sealant/epoxy/spray foam
on the already assembled joint?
We are talking a fairly small gap...
Help!

More silicone!

Make sure the surfaces are dry. Use a hair dryer
on the porcelain.

Apply caulk to both sides of the Mack washer.
Apply caulk generously to the *threaded* part of
the tailpiece. Yes! If you don't, water will spiral
right down the threads.

If you use a big enough glob of caulk to fill the void
in the porcelain, and let it harden, this repair should
last forever.

Jim