On 11/11/2019 13:03, John wrote:

The essentials of good fittings a Cleanliness, No burrs or scratches, no
cuts in washers.I cant help but think that ptfe as a lubricant is a bit of
a comfort blanket / snake oil.

I find it works well on the occasions that some lubrication is required,
and also eliminates the loud squeak you can sometimes get on tightening
compression fittings, which may be important in some circumstances.

Why not a spray of oil?

Less mess, no risk of contamination in the water, and less chance of
making the spanner surfaces of the nuts slippery.

Remember to witdraw
a pipe from the compression fitting by a few mm before tightening so that
both ends of the olive see the force (ie. The pipe is not bottomed)

I can't see that will make any significant difference. The nut will tend
to compress the back of the olive and also drive it into the gap between
fitting and pipe which compresses the front of it. The forces on both
sides will be largely similar and in balance. From a sealing point of
view its the front face that's closing the gap between pipe and fitting
that is doing the work anyway.

In my house only the radiator tails need tape as they seal on the thread. I
am just suggesting that people should consider - what is there to provide a
clamping force and what is there to create a seal. Spending time trying to
add stuff to the clamping medium when it is not the means of sealing is not
a great idea.

I am sure the OP, has got that message by now.



--
Cheers,

John.

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