Having an issue with a leaky sink, the metal thread that comes out of the top of the sink and sits on the top of the plastic tubing is leaking in this area, I’ve replaced the p trap however the plastic nut wont sit straight on the metal thread - could this be due to the blue glue sat in the thread? Do I need to clean this all off before it’ll sit tightly around it?putty say around thread

Sorry if I wasn’t clear I replaced the whole plastic tubing including the nut that should screw on to the metal threading, I replaced it with what was already there. Please see pic, any help would be super appreciated! It seems the nut isn’t screwing on enough and is wonky with the gap on the left wider than on the right, any ideas? Complete novice with these things!

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2 Answers 2


I do not believe the 3way piece you are attempting to attach to the sink strainer is meant to be attached there. You need a Sink tail piece that has a flat flange. Then you will need to get the necessary fittings to plumb from there.


What you have there is quite a mess! Where the drain basket attaches to the sink there is some white gunk, and some blue gunk, and at least one rubber washer, although we can't tell in the pic whether the washer is seated properly or the metal nut is doing its job because of all the gunk in the way.

I would start by completely replacing all that. Take it all apart, clean it up, and if it can't be thoroughly cleaned up just replace it all with a whole new drain. These parts are cheap. Follow a tutorial on youtube about how to install a drain ... but basically ... a rubber washer underneath and some plumber's putty on top. The putty is the only gunk you use but when you're done it shouldn't be visible.

Start with that!

I'm suspicious of the way that white plastic double-wye attaches to the metal tailpiece too. Unfortunately TBH I don't understand it, it has a wedge-shaped tip that looks like a compression fitting but it also has a rubber ring around it. Maybe someone else here will recognize and identify this piece.

Where do the other two pipes go, the ones to the left and right?

  • Thanks Jay! The pipes to the left and right go to a dishwasher and washing machine. That makes sense to be fair, I think you’re right with about the knit going on to the metal it just doesn’t fit correctly. I took it off and cleaned away the blue gunk as was told that it should need anything to attach the Knut on to the metal however I believe the person that out it in must have had the same issue which is why they’ve used the gunk! Will try replacing!
    – Joshj
    Jun 24, 2023 at 21:41
  • If you wanted to replace that double-wye white pipe with a new, more suitable one ... firstly I'm not sure if or how you would find one. I haven't seen two machines connected to the same drain tailpiece. Second, it's not common to connect a laundry machine to a 1-1/4 drain. I would expect the laundry water to back up into the sink. I guess it must be working for you? Is it an unusually small machine? I wish I had better advice.
    – jay613
    Jun 25, 2023 at 15:53

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