Pipe Dope?

[mulwyk]

Getting ready to re-assemble the finger strainer and valve to my fuel tank. I keep seeing traces of something red on the threads.

My question: should I be using some sort of pipe dope or sealant on these threads? Something red? What about that teflon tape from the hardware store?

[Vasey fan]

Re: Pipe Dope?

I've always used Fuelube (if you can still find it). Aircraft Spruce is selling an "equivalent" product called EasyTurn, haven't tried it though. Fuelube is tacky and a tan/brownish color.

Some guys use teflon tape, I avoid it on the basis that it has the potential to introduce "stuff" into the fuel system unless you're really careful in its application.

[ROllerton]

Re: Pipe Dope?

Back in the day, that might have been "Red Lead" which I barely remember being sold at the lumber yard/hardware store? I think it got replaced in the 60's by
"pipe dope", which had no lead. Its the grey goop that dried and turns into concrete thereby insuring that you will never get that SOB pipe to come off the valve on the tractor in July in Arizona so you decide to take the torch to it and cut the pipe off and then you screw up the valve and your dad yells at you... oh wait.. Nurse!

I am sure there is a better more technical definition for this, but any pipe connection that seals via thread to thread interference (the fitting into the tank) must have a sealant applied to the threads.

My choice these days for metal to metal is Teflon based pipe sealant, the stuff from the big box aircraft supply place (blue or orange?) in a tube for a couple bucks. Be sure NOT to get any of this stuff where the gas is supposed to be (in the line, on the strainer, in the tank) because it will plug things up. Teflon tape works too, again keep it off the end of the pipe and out of the fuel path.

The original approved stuff might be "Fuelube", comes in a can from "Ohio Industrial Lubricants" A 1LB can will last you a lifetime, maybe two. I use it a lot on restorations and to dress up dried out gaskets. Its also great for lubricating those stiff and sticky imperial valves; keeping them working and not leaking. Gas wont cut fuelube so again, don't let it get into the gas flow or a bit could go down stream and plug up something important. I am not sure if this stuff is still being made, I found my 1lb can from a tent seller at Sun and Fun 10 years ago. I have read that its no longer made.

Doing some web searches, looks like a suggested replacement for Fuelube is
something called "EZ Turn" from United. $22 for 1lb can, $9 for a 11oz tube, etc. The homebuilders seem to be all a flutter about it.

I question if these are the correct lubricants for o-ring based valves or seals. I would do some more study on this before I did anything with aircraft.

On the farm, I switched dad over to permatex #3 aviation sealant (the liquid stuff) liberally on all pipe fittings and I would use that again in a pinch.



You might look here, although there are many other places that sell this stuff too:

http://www.sacskyranch.com/index.html

http://www.aircraftspruce.com/menus/cs/lubricants.html

[VictorBravo]

Re: Pipe Dope?

There's a Permatex product that is dark red or almost purple in color that I used on all my pipe fittings. Worked great, no leaks so far. The trick is to be careful and only put it on the middle portion of the pipe threads, so it does not get squeezed out onto the open end of the fitting. That way you won't have lumps of the sealant able to get into your O-rings or foul a Curtis valve. The stuff is non-drying (unlike regular threadock) and supposedly maintains a gooey consistency so you have a good chance of taking out the fitting at a later date.

Bill

[Mark Julicher]

Re: Pipe Dope?

You can get Aviation Permatex at any auto parts store -- it says Aviation on the label, this is the "non-hardening" Permatex and it works very well on fuel fittings.

You can get Fuel Lube at the local Falcon Crest stores found near most major airports.

Don't even think about using teflon tape. It works, but the consequences of a tiny shred going down stream are not good.

[N74DV]

Re: Pipe Dope?

I used easy turn on all the fuel/oil fittings on my AirCamper. works great.

[Guest]

Re: Pipe Dope?

I like Tite-Seal, ACS, Wicks, Chief, Wag-Aero should have it.