"T i m" wrote in message
...
On Tue, 23 Feb 2016 12:18:35 GMT, DerbyBorn
wrote:



I've always felt it should be possible to get a good seal without
bodging with silicone or plumber's mate, especially if the surfaces are
clean. A bit of washing up liquid for lubricant, that's all.

This guy uses one:

https://www.youtube.com/watch?v=jaPsf2xTZfc

but also uses silicone, which is cheating IMO

I agree with your thinking - but in this case the thread itself is the
leakage route.

And I can't see how any 'rubber' (that isn't liquid) will ever fully seal
what is a fairly sharp metal thread, without some additional sealant?

Easy, it just gets compressed into the thread as you tighten the nut etc.

The sharpness is irrelevant if it isnt rotating against the
sharpness as you tighten the nut and that is easy to achieve.

The only exception would be if the rubber had it's own internal
thread that coincided with the thread on the waste fitting

And that is what it has,

but even then it would never fully 'sync' (excuse the pun),
depending on how much you compressed the rubber.

That's not right. It's the compressing of the rubber that does that.

It is my prediction that it will still leak,

Bet it doesn't.

it might just take a bit of time till it does

Why should it take time to do that ?

but then may block itself with gunge as time goes on.

Bet it doesn't leak at all. I never sealed any of mine with
anything and none of them have ever leaked in 40+ years.

At least if you applied sealant to the inside of the rubber bush to
seal against the threads you could still easily remove the nut at a
later date.

And if you don't use any sealant, it will undo fine at a later date.