In article , David W.E.
Roberts writes
.
I have just fitted a few compression joints in an area where I wanted to use
copper because it is stronger than plastic and I wanted it to be self
supporting.
[Also I had run out of Speedfit joints and had some legacy compression
joints]
It all worked, but took ages, plus two spanners and a load of PTFE tape.
One joint leaked a little, but was cured by undoing and re-fitting with
extra PTFE round the thread plus some PTFE round the olive.

I found that using PTFE tape on compression joints makes them leak more
rather than less, so I stopped using it. Subsequently I have got into
soldering instead.
--
Tim Mitchell