What is the secret to getting a leak free joint where the drain
connects
to the wash basin? I've managed in the past, but never on the first
try
so I must be doing something wrong. My technique, read off of
instructions for installation of the drain, is to roll a gob of
plumber's
putty into a rope about 1/4" in diameter and lay it in the depression
in the basin where the drain goes. Then I drop the drain in, work the
rubber grommet up over the drain from below, put the washer and nut
on,
and tighten the nut. Then I peal away the putty that has been sqeezed
out
around the drain and do a leak test by closing the drain plug,
filling the basin and letting it stand. After 10 minutes
or so I put my hand down there and find wetness. Since it gets wet
when the
the plug is in place it must be leaking around the putty, right?

At that point I loosen the nut and work the drain up far enough to
squeeze some more
putty in, but that seldom works and I have to take it all apart and
start from scratch.

Could someone clue me in?

TIA