Yellow tape with Inverted Male Flare?
But be very sure to place the tape so no stray strands or bits of it can break off and cause trouble when assembled. I try to leave one thread near the open end of a fitting clear of any tape to prevent Teflon debris from traveling into other parts of the system.
Rich, KE4GNK/AE, Overkill Engineering Dept.
'The Silver HamShack' ('07 International 22FB CCD 75th Anniversary)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch, Prodigy P2 controller.
2012 shortbed CrewMax 4x4 Toyota Tacoma TV with more antennae on it.