I'll give you guys a tip on a killer sealant that you can get at pretty much any auto parts store... Hylomar. It is a blue paste. I first started using it on head bolts that go into water passages. And now when I hard line a system, if I have any difficult to seal flares, I will put some on the sealing surface, and problem solved.
gas tape line, the yellow stuff works awesome if you are having trouble getting regular teflon to seal. Ive also had alot of succes with some yellow paste stuff i picked up from the hardware store. I cant remember what its called, but it sjust yellow paste stuff. Ive never had a leak, but ive only used that on a few fittings. But ive got regular ole teflon, the gas rated yellow teflon, and some yellow paste stuff. No leaks.
like said its all in how you wrap it. You want to wrap the teflon on to there threading it in tightens it around. which would be counter clockwise on a standard right hand thread piece. And you dont need six wraps, a good solid two or so wraps is more than enough