Yellow PTFE on petcock threads?
 

Hello

I'm having trouble with weepy petcock threads on my 1972 Triumph Tiger and I would like to put some Yellow PTFE or Gasolia tape on there. Brand new petcocks, recently cleaned tank, brand new Dowty sealing washers everywhere.

All the old boyz in the bike forums say that yellow PTFE is great or that the bike will immediately self destruct just on the mention of it, so I figured it would be fun to see what you say.

What do you say?

SmileWavy

In my former work world Yellow tape was for natural gas. We only used Rectorseal No. 5 on gasoline of fuel oils. In my experience (47 years in industrial / commercial plumbing) sometime PTFE can be too slick and the fitting can be made up "too tight" and be in danger of damaging either the fitting or the female item being threaded into.

Cheers

Teflon tape should work, just wrap it once. Pipe dope should work as well

What thread size is it 1/8" or 1/4"? If it is 1/8" better to use the white teflon tape, just keep it back from the first thread, only difference between white or yellow is thickness of tape. You said all the parts are new so no chance that somebody used a NPT fitting into a BSPT thread.

Connecting to female plastic threads?
If so good luck!
Over tightening is the biggest issue.
Use good pipe dope!

I have found Seal All brand sealant, available at most auto parts stores, to be absolutely gasoline proof. I have even used it to seal an actively dripping puncture in the bottom of a buddy's early 911 gas tank after one of our typically ill -advised off road adventures when he bottomed out. I used it to seal the seam between the upper and lower halves of the carbon fiber gas tank on my Ducati after ethanol enhanced gas ate through whatever was originally used. It's soft enough to allow you to take things apart later if you need to as well. Good stuff.

No, metal. No worries there.

I hope to be able to remove the petcocks someday as well :D