MTFCA Forum

What thread sealant should be used on the sediment bowl to tank, gasline "elbow" to sediment bowl, gasline "elbow" to carb? I do have the Permatex product shown in the attached photo, but it is not clear to me if this is compatible to gas.

What thread sealant for radiator petcock? Could it be same as used for gasline elbows?

I use yellow Teflon thread sealing tape. Unlike white Teflon tape, yellow Teflon tape is for gasoline threads. You can order it from Amazon. Jim Patrick

The reality of the situation is that there really isn't a good thread sealant for gasoline parts. Yellow teflon tape is made to seal natural gas fittings, not gasoline. Gas versus liquid sealing is completely different. It will not resist.
As for the petcock, teflon tape would be fine there.

From Mr Google:
Is yellow teflon tape good for gasoline?
Due to its chemical inertness, PTFE tape is resistant to both petrol and oil. Therefore, it is often used in automotive applications to seal and lubricate fuel line joints.
My understanding is that although it is designed for natural gas lines it is the best teflon tape for liquid fuels as well.

Harry Lillo

" Gasoila " soft set thread sealant... also has PTFE.

The only difference between yellow and white PTFE tape is the thickness.

I've used Loctite 567 & 577 on my cars without any problems.

Permatex list their High Temperature Thread Sealant as suitable for fuel fittings:

https://www.permatex.com/wp-content/upl ... /59235.pdf

I use good old Permatex no 2 gasket cement. I have an aversion to using sealing tapes of any sort. They will leave bits/threads of tape on the inside, and leave visible eyesores on the outside of all fittings. The brown Permatex just gets lost to sight.

Alan from down under.

I've never disassembled a factory gasoline fitting that showed any evidence of any kind of sealer, other than o-rings on later model stuff. As for antique fittings, I'd think a very sparing application of a graphited grease on threads would be sufficient.

EZ Turn Fuel lube. Works for FAA, should work for a T.

Allan wrote: ↑

Wed Jun 15, 2022 3:56 am

I use good old Permatex no 2 gasket cement. I have an aversion to using sealing tapes of any sort. They will leave bits/threads of tape on the inside, and leave visible eyesores on the outside of all fittings. The brown Permatex just gets lost to sight.

Alan from down under.

Permatex aviation form a gasket, I believe has the same performance rating as #2. These are both good.

I'm with Robert Gasoila is great, If you have damaged threads and want a permanent installation the red hard set is good also. The issue with Teflon is it is also a lubricant and if you over tighten the fitting in the carb you can crack the carb. I have used Teflon tape to seal a float bowl once by taking 3 feet of tape and spinning it with my fingers into a thread then doubled and tripled it into a rope the with the nut loose wrapped it around the threads and tightened the nut to get someone through a tour
Craig.

white or yellow teflon tape will, somewhat mysteriously, nearly always show up somewhere in a carburetor, sooner or later. I used to be a fan and proponent of the stuff. No more. Gasoila or Permatex #2 (my favorite) for me.

the added feature of teflon tape, besides its ability to drain a tank through the float valve when a bit ends up there, is that it provides a nice slick fitting which will very handily burst an NH casting with relatively little effort, where Gasoila and Permatex both transmit a good tactile feedback to you telling you to "STOP!"

TXGOAT2 wrote: ↑

Wed Jun 15, 2022 8:12 am

I've never disassembled a factory gasoline fitting that showed any evidence of any kind of sealer, other than o-rings on later model stuff. As for antique fittings, I'd think a very sparing application of a graphited grease on threads would be sufficient.

Right?! With some of these posts I forget we're talking about a model T. If you need sealants with brass fittings that is a problem.
Disclaimer. Felt sealed fittings not included.

I use fuel lube which may have a new name now. aircraft spruce sells EZ Turn.

"EZ Turn is a specialty lubricant/sealant used for fuel and oil line valves & is resistant to high temps. Especially effective where high octane fuels and aromatics are present. EZ Turn is also extremely efficient as a gasket paste & anti-seize agent. EZ Turn will not gum, crack or dry out. Each shipment is independently tested. Excellent for tapered plug valves, aircraft engine manufacturing, and marine applications. EZ Turn is the functional equivalent of fuel lube"

When using Teflon tape ( for you military people its Sealing Tape Teflon) it needs to be wrapped in the direction it is tightened in and should never extend past the first thread other wise it will end up in places you don't want it in.
Craig.