I installed a bathroom sink, and it hasn't fallen yet! However, installing the drain has not gone as well, it leaks right out of the basin. I have opted for one of the drains that uses a rubber plug rather than the drain that attaches to the plunger thingy between the faucets. Anyway, the install appears pretty simple, put the drain part in from the top, put some sealer around the flange (inside the basin), then from underneath put the rubber fitting and the nut, tighten, connect to trap and voila.

But, it’s leaking. Coming out around the rubber fitting under sink.

My thoughts were that I should have used some thread tape and/or sealed the rubber fitting to the sink. But in looking at sinks in my rental house I see no sealer or tape, and they don't leak. Maybe I tightened too much and have caused a gap in the rubber fitting?

John.Swaro