Tip to secure kitchen sink waste right below sink to trap

[silver50]

It's the first connection under the kitchen sink which had gone very loose and was of course leaking. A grey plastic B&Q waste/plug etc joint by white nut from the waste trap/bend. The plastic nut just about tightened but went loose, however it went tight enough to seal again I suspect it will be ok for a while however I can see it loosening off after a number of kitchen sinks are emptied!

I don't actually know if it's the threads on the grey B&Q sink part or the plastic nut on the top of the trap at fault. Threads looked ok to me on the grey plastic though

Is there anything I could try to get the plastic nut to stay fixed so as it doesn't loosen off in time(being tight enough just now) i.e. a thread lock of some sort or silicon? I feel it just might not be necessary in the meantime to start replacing one or both-especially not knowing which is at fault, plus the grey sink part is well siliconed on to the stainless steel sink etc

Thanks

 

[tincup]

Hi

Try wrapping ptfe tape round the threads it might help it seal.

HTH.

 

[Charnwood]

Is there a rubber ring in the nut of the trap?

 

[sooey]

Some of those cheap pastic fittings do jump on the thread just as you're getting them reasonably well nipped up, even by hand.
They're a nuisance but as tincup said a good few wraps of ptfe wound tightly round the thread should help it to hold.
Though replacing both would be the best option.

 

[silver50]

Thanks for replies

I should have said I actually did wrap a wee bit ptfe tape round it. Maybe should've used a little more, I didn't have much left on the roll- I might actually try that again, as you say it might just do it

Not sure if there was a rubber ring on the nut. Certainly seals where the trap went onto waste, but dunno about the nut itself- I didn't really know there was another there

 

[Charnwood]

The washer I mean is
View media item 63601

 

[sooey]

If you undo the nut there should be a lip on the pipe inside it, with a thin rubber seal.
You need about ten or so wraps of ptfe tightly wound round the thread in the same direction as the nut tightens to have a chance of it not jumping.

 

[silver50]

I think the rubber washer probably was there but i'll need to check when I look at it again

MANY THANKS for such helpful replies

 

[Madrab]

make sure the rubber sealing washer isn't twisted as this can sometimes happen if it's an older trap and doesn't sit square on the lip..