On Mon, 16 May 2016 00:48:06 -0400, wrote:

On Sun, 15 May 2016 10:32:04 -0700 (PDT), bob haller
wrote:

a plmber i know uses both, teflon tape and then pipe dope


he has been a plumber forever and said it guarantees no leaks

Teflon tape is not supposed to be used on natural gas lines. Something
about the gas dissolving the tape. It's ok on propane though. There is a
special tape made for nat. gas, but I have never used it. so I dont know
the name of it, or if it's readily available. Years ago, I did some work
on nat. gas pipes, for my parents. I just used pipe dope. Where I live
now, I only have propane, but I still use pipe dope. Normally people use
copper tubing for propane, so no sealer is needed since the fittings are
flared copper or compression rings. But my house had black iron pipe for
the furnace. When I ran a line to the kitchen for a stove, I decided it
was best to keep the same pipe to prevent dialectric corrosion, so I
used black iron pipe with dope in the fittings.
More polichromatic bovine excrement.. Natural gas and propane have
the exact same effect on teflon tape - none at all.

However, pipe dope mis recommended over tape because the tape can cut
and turn into "threads" of teflon and block orifices or stick in
valves. There are 3 basic teflon tapes - white(single thickness) ,
yellow (double thickness) and pionk (triple thickness. White is
forbidden in all gas connections. Some places allow yellow - some
allow pink, and some do not allow tape at all.