Sealing off your petcock

[Airwolfie]

I have an aftermarket petcock and tank, so it's not like the original. It has a 3/8" thread slightly tapered, so it tightens as you screw it in.

My question is, do I have to add anything to seal it off? Or will the thread seal itself? Me and Dave were discussing this last night. I'm thinking plumbers tape would dissolve in petrol no?

Any thoughts or tips??

 

[Hairic]

I say take some plumbers tape and stick it in a cup of fuel and see what happens. I may do that just cause Im curious Now.

 

[Airwolfie]

I say take some plumbers tape and stick it in a cup of fuel and see what happens. I may do that just cause Im curious Now.

AHAHAHAAAA!! that made me laugh!!!

 

[OldskoolXS650]

When I bought my brass Golan petcock the instructions said use plumbers tape to stop the petcock in the correct orientation (clock) and use a paste sealer with Teflon. I did this and no leaks so far.

Posted via Mobile

 

[gggGary]

Teflon tape, the yellow teflon tape for natural gas is a bit thicker but the white stuff works too. Avoid any getting inside the tank, it could plug a line or valve.

 

[wherearewe]

Permatex make a thread sealer for exactly this purpose. Its like a rubbery white sort of stuff.

 

[I am Carbon]

Well I thought I would chine in.
The white Teflon tape works.
I use prematex aviation liquid gasket sealer.
It works good too.

 

[RatyXS]

I have never had one leak, have used nothing. Only use the tape when you need to get a little more turn on it. Also note you should never use the tef tape on metal or barass into aluminum.

 

[Airwolfie]

Awesome replies! Thanks guys!!

 

[gggGary]

I'll have to differ a touch with I am carbon on this one. Aviation gasket sealer should not be immersed in gasoline. It dissolves and heads for the lowest point in the fuel system, the float bowls, then congeals into a tarry mess. I had to clean up after a PO used permatex gasket cement trying to seal the stock petcock to the tank. It was f-ugly in those carbs.

 

[Airwolfie]

I'll have to differ a touch with I am carbon on this one. Aviation gasket sealer should not be immersed in gasoline. It dissolves and heads for the lowest point in the fuel system, the float bowls, then congeals into a tarry mess. I had to clean up after a PO used permatex gasket cement trying to seal the stock petcock to the tank. It was f-ugly in those carbs.

Thanks for the heads up Gary!

I think I'll stick to the plumbers tape for now, I don't trust the thread alone will seal off completely!

 

[RatyXS]

Tef tape will deteriorate with gas, they make a special tape for gas applications.

 

[wherearewe]

Yes basic teflon plumbing tape breaks down. I went to a couple of shops locking for a tape resistant to fuel and the guys behind the counters looked at me like dogs just shown a card trick. Can someone give me an ebay link or some such?

I would have thought Permatex thread sealer, designed for sealing pipe threads carrying solvents was a pretty good option... Cant speak about long term though...

http://www.permatex.com/products-2/...ants/permatex-thread-sealant-with-ptfe-detail

 

[RatyXS]

Should never use RTV or anything that can break down or flake off and mess with the fuel system and carbs. I will try to find a link for the tape. Google gasoline seal tape. Home Depot sells it I think

 

[Airwolfie]

got no home depot in the Uk...........

 

[wherearewe]

I don't seem to be able to find anyone selling it where i am either, find it on ebay though under yellow teflon tape.

 

[Airwolfie]

I just googled it and all I come up with is PTFE tape. also some mention of Hylomar gasket sealer and Locktite.

If I find out any more I will post it up here.......

 

[glennpm]

I was introduced to this sealant, LOCTITE 565 PST THREAD
SEALANT, when I bought my Buell Ulysses. It is specified on the oil sump drain bolt, works well and I've used it elsewhere. I think it would be good for this application.

" Loctite 565 Thread Sealant

Loctite® 565™ Thread Sealant, controlled strength, is formulated specifically for metal tapered pipe thread fittings. Controlled lubricity prevents galling and protects from rust and corrosion. Loctite 565 replaces most tapes and pipe dopes. Cures rapidly to withstand 10,000 psi. Perfect as a replacement for pre-coated parts. Can be used on fittings up to 2 in. (50 mm) in diameter"

 

[gggGary]

I went looking quite a while ago on gasoline the tape/sealer question. There is no holy grail of yes no on teflon tape vs gasoline that I have ever found. I have used it without problem. The "gas" tape is NATURAL gas tape, it's chemically identical to plumbers tape but is twice as thick and is colored yellow. Plumbers are always cautioned about letting tape get inside the gas piping system, tape shreds fouling gas regulators, orifices is a constant concern.
I think it's possible that due to liability and fuel blend issues that "rated for gasoline" is a very hard thing to come by.

 

[pa-powerstroke]

I work in the gas and oil industry and we use white teflon thread tape all the time. Its used to seal threads on things such as grease fittings on frac valves, the things see pressures up to 10,000psi and are used under hellish conditions. They see very corrosive and solvents, chemicals, and acids and hold up very well. I would not be afraid of using the stuff on petcock threads. Just make sure to wrap the same direction you will be turning the threads so they do not unravel and become bunched and also to leave the first thread free so pieces of the tape dont end up in the tank. Hope this helps.