I'm swapping out stock galvanized gas tanks for plastic ones. ( They rusted out). Question is: With exposed contacts on the fuel pump and sending unit sitting in a gas/air mix will I now have a spark issue, and if so, what is the right way to deal with it?
NO GUESSING HERE PLEASE!! PRO'S ONLY. Thank You...

 

you disconnect the battery first and i am not guessing.

 

usually the first step in any procedure is to disconnect the negative lead on the battery.

jason

 

Thank you quicklook. I should have been more detailed. I was wondering if there would be a grounding issue with the electricial components (e.g. pump and sending unit) if you switched from a metal gas tank to a plastic one. My concern is that, without the right grounding, a plastic tank might have the potential for static discharge when the pump or sending unit are energized. The electrical contacts for both are totally exposed and sitting right in the gas.

 

You should not have any air (oxygen) in the tank and the gas fumes on top of the liquid gas should be to rich to burn. If you have a hole in the top of the tank letting air in then you need to replace the tank.

Do not believe the NTSB fuel tank theory on why the TWA off NY went down, that was not possible for a spark in a diesel (heavy oil) tank on a plane to blow up.

I am not a PRO on plastic tanks and I do not know where you would find one.
I do not know why I would ever want to use one although I did have the tank on my 66 lined.

 

Broncograveyard carries them.

 

Obviously, yes, disconnect the battery. 12v power is wonderfully effective at generating sparks, so by disconnecting it will be prevented.

The risk of plastic involves it or you building a static charge, and then discharging the static in the presence of fuel vapor. You yourself are highly unlikely to build a charge, since you'll be touching the frame of the truck and/or the actual ground. The tank will not build a charge as long as you keep it in contact with the frame ground or earth ground. The fasteners holding the tank in place will be more than sufficient grounding.

The only thing you may want to watch for would be the plastic tank sitting in a plastic bed and sliding around and building up a charge. Simply setting it on the ground or touching any metal part of the truck will discharge it. The reason plastic fuel tanks are a danger at the gas pump is if it sits on a plastic bedliner, slides around and builds up a charge, and the first grounded thing it contacts is the fuel nozzle.

The situation where you can build a charge is getting in/out of the vehicle, wearing insulated footwear, and not touching metal on the car. If the door is already open, it's not hard to do and the sliding of your clothing on the seats can generate some static. If you've already got the fuel pumping, then it's possible to discharge yourself on the fuel nozzle where there is a plume of fuel vapor. The real risk of cell phone use comes from this sequence of events.

Dave

 

I got the gastank renew tanks, basically a redid sealed tank in and out.
Lifetime warrenty i think, unsure.

 

I would like to thank everyone who posted info on this topic. I got the tank in over the weekend and all seems well. Kudos to subford and dgeesaman for a primer on static charge. Have a cold one on me and take care.