I replaced a friends bathroom sink tailpiece yesterday and I am having
problems with a leak in the pipe with fine threads that goes into the
main body of the tailpipe. It is part RP 6128 in the pic below.
http://www.naturalhandyman.com/iip/i.../i/infpop1.gif

When I first installed the tailpiece, it leaked. So I removed it and
used teflon tape, still leaked. Then I used Rectorseal teflon pipe
seal, still leaked.

So I thought maybe I have a defective pipe. So I got a new one,put it
in, same thing, still leaks. Any ideas? I'm ready to put 5 minute
Epoxy on this thing if i can't stop this leak.