Using copper for fuel fill line

[JeepinPete]

Can anyone give me a good reason why this is a bad idea? I am thinking of using 1.25" copper fittings and tubing for the fill pipe. Soldering it all together using silver solder, since it is much stronger and ductile than lead/tin solder, from what I understand...

[gsmikie]

i used pvc or exhaust pipe

[Lindel]

I've used it for fuel line in the past, don't see any reason why it won't work for this. Other than the cost involved, it shouldn't be any big deal.

[Cranky_Joe]

The only reason not to use copper is the vibrations of running the vehicle cause the metal to fatigue. If "hard plumbed" to the carb, that is copper from the carb all the way to the frame, then the tubing will eventually split.

The vibrations can be minimised by putting in a "service loop" and/or by breaking up the copper and using a flexable material for a short span. The flexible material will absorb most of the vibrations, and perserve the copper. The service loop acts as a spring and better absorbs the vibrations. However even with a service loop, the copper will eventully split.

Good luck, let us know how it turns out!

[JeepinPete]

Agreed on your points Joe, but I am not going to use copper to plumb to the engine. Steel brake line is cheap and easy to bend. I was refering to the fuel filler pipe, that goes from the gas cap to the tank itself. I've installed a new tank in the rear of the Cherokee, and need to run a new line to the tank. My thinking is the vibration back there will not be nearly as bad, and larger diameter copper has a significantly thicker wall that most of the small diameter stuff. Plus it is readily available.

[chrisnsarah]

It's not affected by gasoline, so you can use it. You just have to deal with the flex issues like everyone said, and use Type L at least.

I used a copper elbow for running my fuel tank vent line around a tight bend and hose clamped it to the rubber lines. It's holding up fine.

[jeepguzzi]

You will want some kind of fuel resistant rubber line between the tank and the filler tube.

The body will flex in different directions than the frame, and I could see it splitting the copper pretty easily. There is a reason there is not a solid tube between the tank and body.

[j20jeepin]

My concerns are more with the issue of static electricity between
the fuel tank and a gas pump or other source. Could be all wet here, need
to hear from someone with electrical knowledge.

[gwinn]

There will be no chemical reaction between the fuel and the copper. There will be an electronic and corrosive reaction anywhere where the copper comes in contact with steel. Also the copper will work harden as it flexes and in time will simply snap at these stress points.

[710 Burner]

Originally Posted by jeepguzzi

You will want some kind of fuel resistant rubber line between the tank and the filler tube.

The body will flex in different directions than the frame, and I could see it splitting the copper pretty easily. There is a reason there is not a solid tube between the tank and body.

I am in full agreement with jeepguzzi here. As far as static, I don't think you will increase or decrease any incidence of static discharge. For the most part you need to watch out for the body of the vehicle here.

[JeepinPete]

Agreed about vibration. I intend to rebuild the fill pipe from the cap to underneath the body. At that point I will put in a piece of rubber hose back to the tank inlet. Thanks for the input guys!

Originally Posted by j20jeepin

My concerns are more with the issue of static electricity between
the fuel tank and a gas pump or other source. Could be all wet here, need
to hear from someone with electrical knowledge.

Not much on electrical knowledge , but a strap around the pipe to ground should take care of static charges.