What I currently have is a plastic washer under the nut on the end directly attached to the sink. My problem is the other side of the trap pipe. That is where my leak is. I was told by a guy at Lowe's that this side is not supposed to have a washer (which mine does not) and that it is simply supposed to sit perfectly against the pipe leading away from it and then have the nut screwed down to hold it there. Essentially the 'perfect placement' of one piece against the other is supposed to create a seal. Well I bought a new trap in the hopes that mine was simply out of shape just enough to cause it not to sit perfectly together and it is still leaking. I am baffled by the lack of washer here. Is his assessment that 'fitting perfectly' is key or is he a bumble head and I need to have a washer? Oh it is black pvc piping and the upper pipe that the trap is supposed to fit against has some kind of lip on it and I can't even get one of the plastic washers that came with the new trap on past this end."

Apparently it won't let me add pictures :(

Hi Brokenhouse...

If I understand you, a kitchen sink tailpiece is FLANGED. On the flanged end you need to place a FLANGED TAILPIECE WASHER against the sink strainer... see images below.

The black tubular ABS PTRAP itself usually has a mechanical sealed joint and yeah these don't have a washer.. see image. You could use some pipe dope at this joint... should help, but things need to line up perfectly.

Metal tubular PTRAPs usually need a washer at this joint... see image below.;)

Let me know if this is what you were asking about...

Mark

Yes, it's that "mechanical sealed" end that is giving me trouble. I did not have pipe dope but did have clear silicone (that I used to repair my fish tank) so I used that around the joint under the nut. Thanks so much for clearing up the mystery!!