Therad Sealant

[1970 XLCH]

Any suggestions on a thread sealer for gas tank petcocks ? I used teflon tape on my VL and it decomposed , causing paint damage . Thank you for the help , Mkie

[Grumpa]

A lot of people use Teflon tape on threads with the expectation that it works as a sealer. The primary benefit of using Teflon is that it's a lubricant and ends up inadvertently sealing a pipe joint but it's really not a sealer. Plain old plumbers pipe dope works for me on low temp applications like gas petcocks.

[BoschZEV]

I used teflon tape on my VL and it decomposed

You might have used white tape, but it wasn't TeflonŽ. If it was, it wouldn't have decomposed in contact with gasoline (or E10 gasoline, or diesel fuel). Notwithstanding the previous post, TeflonŽ tape is an excellent sealant for gasoline fittings. You'll have to pay a little more for the genuine stuff, but the genuine stuff is impervious to anything that comes out of a gasoline pump.

[Omarttentmaker]

I use stuff called "Gas-oila". It's the same consistency as plumber's putty, but resists all types of fluids (gas, oil, water, etc.). Comes in a white toothpaste-type container. I know it works well because I've used it at the banjo junction on the tank crossover line with great success. I coat both sides of the banjo fitting and both sides of the brass washers before installation.

[BoschZEV]

In addition to teflon tape, I rely on 'EZ Turn' sealant from Aircraft Spruce to seal connections in gasoline lines where the tape won't fit (e.g. compression joints) as well as lubricate petcocks.

[Rollo]

I use the white Teflon tape on oil line fittings but use the Permatex pipe joint compound on gas fittings as it is gas resistant. It is brown and has a brush in the container to apply it. It is thinner than regular plumbers compound but it is gas resistant. You can get it NAPA or better auto parts supply houses.

Tom (Rollo) Hardy

AMCA #12766

[tfburke3]

Teflon ribbon packing is used extensively in such places as oil refineries and is a great thread sealer.Because it is packing and has structure it can also be used to say pack a faucet stem in a pinch.
Teflon paste such as Slick Tite also works but drips at first heat cycle.
Leak Lock is also popular in the hvac industry,or just use some permatex#2
Tom

[exeric]

I've never had any degenerative problems with a quality Teflon tape; and like Omar, I use Gas-oila and highly recommend it.

[T. Cotten]

I've never had any degenerative problems with a quality Teflon tape; and like Omar, I use Gas-oila and highly recommend it.

Sorry Folks!

Gasoila does not survive modern fuels.

(It should especially be avoided for sealing engine case interiors on OHVs that may suffer a leaky petcock.)

The petcocks and other appliances depend upon a mechanical seal.
If your goober survives, its because the hardware worked as it should.

....Cotten

[Omarttentmaker]

Hey Cotten...I can't believe I got that lucky that many times in a row! And this after repeated attempts including precision grinding the banjo fitting parallel and annealing the brass seals.