Fuel-safe thread sealant?

I need a thread sealant that won’t dissolve in gasoline. I’ve read teflon tape works, but I have a hard time trusting it on anything beyond water.

What have you guys used?

Yellow teflon tape is meant for gas/oil.

Beat me to it. There is also liquid type available from permatex that I use as well. Can I ask what you are using it on?

He’s building a fuel rail, Dodge turbo four.

When I built the Honda I used the white stuff. Never had any leaks, but I didn’t keep the car long after building it.

That yellow tape “gas” rating is for natural gas and propane as far as I knew, not gasoline.

I found an MSDS on it and it and gasoline isn’t listed under incompatibilities so I guess it’s ok though. I’d still feel a lot better if it said “gasoline” for the usage somewhere.
http://www.antiseize.com/msdsshts/m46300.pdf

But any tape is going to lead to problems down the road since if you ever unscrew it you’re very likely to get little shreds of tape in your line. That stuff turns into a mess when you take it apart.

So the fittings at the end of a rail? They typically use an o-ring to seal there. Is this being custom made? what find of fitting is it being made to use? Since he is wanting to thread seal and not o-ring I would use the yellow tape if anything. NPT I assume?

You are correct about the yellow tape being for Natural Gas. Not Gasoline. I believe it’s the same material, just thicker.

The yellow tape is not just for natural gas. It has right on the front a large list of things it can be used for. I only remember because I was reading through them to see if I could use it on an oil fitting. I did it with white twice and it dissolved and the yellow worked great. I also keep this around and it should work.
http://www.permatex.com/products/Automotive/thread_compounds/a_thread_sealants/auto_Permatex_Thread_Sealant_with_PTFE.htm

I still think that it should probably use a a rubber o-ring to seal though.

The fuel rail on the honda didn’t use an o-ring. Interesting on the yellow stuff though. I’m gonna keep it in mind.

I do not know 100% that it can be used on gasoline so I would double check. So the fitting was NPT and sealed via thread taper? If this guy is making one or it is aftermarket he should deff set it up to be compression/o-ring sealed like most all aftermarket rails.

Well, this was an aftermarket rail with a port on the blank side to allow for a pressure gauge to be installed. I installed a gauge for troubleshooting directly onto it. It was taper threaded and I just used the white stuff. I probably should have done more research on which tape to get. eeek.

I can’t remember how the hose hooked up on the other side.

He is using O-rings. I’ll let him finish the details but it’s legit.

I’m afraid I tapped both ends with 1/2" npt taper. I didn’t know at the time that most were o-ring seals :ham:

Here are a few pics of what I got so far:

I might have just enough room to trim 3/4" off each end and re-tap it for a port seal, but then I’d have to add a counterbore for the o-ring to live in and hope that it compresses the right amount. Pipe threads just seem more straight forward and idiot proof to me.

Those are in the super sweet valved quick connect fittings for the fuel line (overkill, but why not if they’re free from work?)

Just picked it up from R&J Metal Finishing. They did a great job on the orange anodizing.

:tspry:

RJ FTW

It’s installed! I used ‘blue monster’ teflon tape. Their tech spec says its good for gas, diesel, jet fuel, etc.:tup:

Yet sadly, I had a leak from a stupid mechanical oversight.:tdown:

The injectors don’t push far enough into the ports to seal properly. A quick trim off the height of the standoffs should seat the injector o-rings right where they need to be.

looking good