On 1/31/2017 7:55 AM, Andrew Gabriel wrote:
In article ,
Graham. writes:
On Mon, 30 Jan 2017 13:43:43 -0000 (UTC),
(Andrew Gabriel) wrote:

In article 2,
DerbyBorn writes:

I tend to think of "possession of PTFE Tape as implying some sort of
aptitude for plumbing."

Inappropriate use of PTFE is also a good indiocation of a cluesless plumber.

I believe the get-out is, "I applied PTFE to the threads as a
lubricant, not a sealant".

...and that's fine, but not when it's applied to the sealing
surfaces of compression fittings or cone joints.

My parents' [then] new ensuite plumbing started leaking ~6 months
after installation. All I had to do was take apart and remove the
PTFE from the sealing faces of the compression fittings (I was
lucky - once used, it will often deform the sealing faces so they
won't seal again, without bodging it with more PTFE).


That can only happen with a very extreme bodge, though. PTFE is *very
much* weaker than metal, and one or two turns over an olive will just
extrude into the space alongside the "line contact". There has to be
enough PTFE to completely fill all the available space, so that you are
generating hydrostatic conditions within the joint.