o-ring seals

Aug 22, 2019 Last reply: 6 years ago 13 Replies

I bought a new bottle trap for under the sink, there is the tiniest of leaks, maybe about a couple tablespoons overnight, its coming from the bottom part (the trap) that screws on to the top part, I have tried tightening a bit more but still drips. Any ideas to seal it 100%, although to be honest I cant understand why it leaks.


Likely not made properly, there is a crack or roughness where the O ring goes.

It happens that ss formulated :

A smear of plumbermait on the threads will help seal it.

Lube the O ring with some silicone grease. If that does not fix it, then Fernox LS-X

Is it plastic onto metal? If so then some kind of deformation probably. Brian

Take it apart and check that the rubber seal is seated properly. I spent quite a while recently swearing at and tightening a new one until I took it apart and found the rubber ring was awry.

Try using Vaseline on the o ring.

Some defect in the plastic seems likely, either a void or sprue which might just be removable.

Almost certainly the cause IMHO. On old, dodgy screw up ones I tend to use the sealers in a squeezy bottle from Screwfix, etc. If it is a push-fit then the easiest fix is a few turns of white pvc electrical tape, applied under tension so that it stretches to fit tightly without creases. Done well, it doesn't look too much like a bodge.

I took it apart, couldnt see any issues, lightly smeared with some grease, back together and now watertight.

sometimes te o-ring ends up slightly in the wrong place. Grease helps it be where in needs to be

It is one of those places where the thread does act (not very well) as part of the seal. You do need something on the thread.

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