Gas shut off valve thread sealer?

[Michael M]

I'm about to replace the gas shut off valve on my '31. I did a search on the forum and found one vote for sealing the threads with pipe dope, one warning not to use pipe dope, and third opinion to use thread sealer designed for gas (not sure if the the reference was to gasoline or natural gas).

May I solicit advice from the Barners?

[Ron/IA]

http://www.permatex.com/products-2/p...sealant-detail

The above address will take you to the Permatex thread sealer designed for such applications.

It has worked for me.

[Jim Baskin III Pa.]

I used Teflon tape on mine.Did that 8 years ago.

[SSsssteamer]

Originally Posted by Jim Baskin III Pa.

I used Teflon tape on mine.Did that 8 years ago.

Ditto here. Used many times on many cars.

[RHD]

Haven't had a lot to do with 31 vehicles, but is that thread not tapered?

[Lona]

Sponsored Links (Register now to hide all advertisements)

I used Teflon tape on my carb inlet last week. Drove the car about two miles and it started to run poorly. Pulled the carb and found a gooey mess of dissolved Teflon tape inside the carb. Maybe there are some Teflon tapes which won't dissolve in gas and if there are, I would like to know the brand if possible.

Glen

[freak]

The carb inlet is a compression fitting and should not have any sealant on it tape or otherwise.

[Tom Wesenberg]

Originally Posted by Lona

I used Teflon tape on my carb inlet last week. Drove the car about two miles and it started to run poorly. Pulled the carb and found a gooey mess of dissolved Teflon tape inside the carb. Maybe there are some Teflon tapes which won't dissolve in gas and if there are, I would like to know the brand if possible.

Glen

I don't use either on fuel lines, but I've read that you need to use the yellow teflon tape for fuel lines, and not the white stuff.

[Rich in Tucson]

Yellow Teflon tape is specified for natural gas use, not gasoline use. However it has been used many times by many folks (as well as with the white) so the choice on whether to use it and HOW to use it is up to you. I use neither on compression/pipe fittings. If the seal is bad (leaks), the fitting is bad (or the threads are bad-look!) and ought to be replaced. I cannot find the source, but my recollection is that Ford specified that gasoline line fittings be used ONCE. They were to be replaced if removed for any reason. I get many cycles of tightening/loosening of gas line fittings (mostly repro modern materials) by taking it easy on the tightening of clean fittings.

[Dusty]

This is what I used on my new shut off valve. It is wet when applied and dries fast, so you need to get the valve screwed up and in before it does so. I think if you let it dry it would just peal off when you screwed it in. Mine has been in for 6 weeks and no leaks.

dusty

[IMG][/IMG]

[700rpm]

Waxed dental floss works for me.

[wawath]

For years I have used Otay brand pipe dope available from Ace hardware for all my fittings. It will stop leaks on anything even high pressure hydraulic fittings. It is good stuff.

[Greg Jones]

The high-tack gasket sealant shown in Dusty's photo is the stuff I typically use in fuel line threads WHERE NEEDED. Good advice to check the threads on everything to make sure they are not damaged. I had a glass fuel bowl that had been cross threaded and seeped gas so my shop stunk of gas all the time. I finally changed it out and no more gas seeps.

I also used this when overhauling the fuel gage-it is just the right thing for that application as well to seal the cork gaskets without "permanently sealing" them. (One guy told me he used gorilla glue!)

[V4F]

Teflon tape or liquid Teflon ........

[imacrazy]

Use the orange Teflon tape made for gasoline. Lowes handles it.

[P.S.]

The new gas eats Teflon. Avoid it.

I replaced the shutoff on my 31 Tudor last year. Used the thread sealer made for use with gasoline, says so right on the tube. It's sorta yellowish and dries hard, not flexible. To remove the fitting later, just whack it and the stuff is supposed to break free. Hasn't leaked a drop in over a year. And this is on a really picky restored car, so any leak no matter how small would be noticed and unacceptable.

Yes, the threads are tapered like NPT. However, I still used sealant just in case since you have to rotate the valve to be in the correct position, you don't necessarily get to tighten as much as you would like or you may over-rotate and the interior fuel line will not line up.

[FL&WVMIKE]

I have used teflon tape for many years with no problem.
You just have to be careful and not let any edges get close to the gasoline. It has to be on the top of the threads, only. It doesn't take much.
MIKE (mikeburch)

[H. L. Chauvin]

Hi Michael,

Below is a $2.99 stick made by Wm. Harvey for years.

It is sold at local hardware stores, (or order on line), for sealing "gasoline" fittings as well as others.

It can withstand 2,000 psi & 3,500 degrees F.

Unless you intend to attach a 2,300 psi air compressor to your gas tank, or heat your shut off valve cherry red with a torch, this product will work 100% of the time.

I used it for over 60 years with no failure.

Get one (1) stick -- after use, store in a zip lock bag to prevent drying out -- promise it will be the last pipe dope you need to buy for at least 10 years for your Model A & all of the plumbing "honeydo" projects around your house.

Print
Pipe Thread Stick


ITEM 682109 | MODEL #030005-144 by William H. Harvey


Pipe thread compound in stick form. Lubricates, seals and prevents rust and corrosion. Use pipe stick on pressures to 2,000 PSI, temperatures to 3500F for metal pipe carrying water, steam, air, ammonia, gasoline, natural gas, butane, propane, freon, petroleum oil.

Hope this helps.

[rons49]

I have used a product called SEAL All OIL/GAS sealant with excellent results. It is a couple of dollars at Ace hardware. It comes in a small "toothpaste" tube. I made an adapter that threads on to the open end to make precise applications. It has lasted for years on my Cadillac & is a fine sealant for the fuel gauge sender unit screws etc. and tank fittings. Never needed it on my A.

[Mitch//pa]

has anyone tried doing it dry

[larrys40]

Yes. Worked all the time for me if the ferrule is bad replace it if the seat is bad Regrind it
I never use any sealant or thread tape. Sometimes a new line w fittings is in order
Larry

[C4engr]

The gas shut off valve uses a compression fitting. You are not supposed to use a sealant on gas lines... That is a No_No.. That is why there are compression fittings on the lines.
Furthermore with today's gasoline one never knows what it will eat.
My advise is USE NOTHING... my experience after 40+ years of A driving...
If the valve leaks at the fitting IT IS THE FITTING and SHOULD BE REPLACED..
The fittings are cheaper than a roadside repair or tow...

Rog

[marc hildebrant]

Originally Posted by Michael M

I'm about to replace the gas shut off valve on my '31. I did a search on the forum and found one vote for sealing the threads with pipe dope, one warning not to use pipe dope, and third opinion to use thread sealer designed for gas (not sure if the the reference was to gasoline or natural gas).

May I solicit advice from the Barners?

Which part are you referring to ? The part that threads into the gas tank ?

Marc

[Michael M]

Thanks for all the advice. I see there is no consensus as yet, but it's good to see that there is a variety of choices that seem to work.

Just to clarify, I am speaking of the threads that connect to the gas tank. I would not put anything on the compression fitting.

I guess my concern is that for the valve to align, I may not be able to tighten as much as I could. Just wanting to have an 'insurance policy.'

[H. L. Chauvin]

Hi Michael,

In reply no. 18, with the pipe stick solution, we can add this:

1. Murphy is hiding in every Model A garage & he is just waiting to show you his law.

2. This pipe stick can tell Murphy to go fly a kite.

3. With a new 90 degree gas shut off valve, the horizontal oriented flared fitting for the very rigid steel gas line is not a Murphy curse & will never need the pipe stick.

4. The vertical threads screwing into the gas tank is what Murphy is watching.

5. Just as you screw in the "new" shut off valve & it feels tight, Murphy attacks & shows you that the flare fitting should have stopped at 12 0'clock on the passenger's side of the gas tank .............. but this new shut off valve passed by 12 o'clock & went clockwise to one (1) o'clock.

5. So if you pass (1) o'clock & go clockwise to get to 12 o'clock, the threads could strip.

6. The stick can help.

7. Just unscrew the new gas line, apply a 2nd coating of pipe stick compound, stop at 12 o'clock, & allow the pipe stick compound to cure for 24 hours before turning the new shut off valve handle.

8. Murphy quit coming in my garage for threaded gas tank fittings, threaded carburetor fitting, & oil drain fittings years ago -- I think Murphy was looking at my 6V battery a few days ago, but I got a new Schumaker battery maintainer from Amazon.com yesterday.

[Lona]

Sponsored Links (Register now to hide all advertisements)

Freak,
You're right. I said the gas inlet but meant the GAV inlet. Others have suggested some alternatives for the white tape which I will follow.

Glen

[billwill]

Use sealer for gasoline ggggggo luck

[Doug in NJ]

I used Permatex #2 because I had it laying around, and no sign of a leak after several years.

On a slight off-topic: what's a good sealant for radiator hoses that have a slight leak?


Doug

[Bruce Adams]

Permatex Number 2 has been sealing fittings and resisting gasoline for decades without ever hardening completely.