I cannot find any reference to gasoline being electrically conductive; therefore, I guess what we are actually trying to accomplish is a way to conduct any static charge in the wing tank and or fuel can to a ground without creating a spark.

The grounding the exterior of the can ( plastic or metal ) should be pretty simple. Ground or wipe the can with something that will conduct the charge to a ground. Something as simple as placing the can on the ground or wiping it down with a damp cloth should dissipate the external charge on either can. I know you in the Great White North have problems with this since the cloth would be frozen in the winter, but I have great trust in the Great White ingenuity and maybe you have to use metal only.

Grounding the interior of the can is more problematical if it is plastic. The welding rod is ingenious, but I was wondering if drilling a hole in the spout near where it attaches to the can and using fuel proof cement to seal a copper screw or bolt attached to a grounding strap would be good solution. Float plane pilots could drop the end in the water.

All this assumes the plane was grounded to begin with. The plane gathers a lot of static charge which needs to go to ground and is probably the source of the majority of the static spark fires.

I have to plead guilty to fueling from cans without grounding the plane and am rigging up a alligator clip and copper rod grounding strap for remote fueling.

I know we have beat this to death, but it is an issue for those who fly with extra fuel on board or have it in their hangers.

TD

Due to the carbon in hydrocarbon, fuel oils are typically not electrically conductive. Which is one of the issues the cause us static problems.

Actually the bonding/grounding of the outside of a plastic can isn't so easy. It's an insulator so it will dissipate charge extremely slowly even when put in contact with the ground. Leave it there for several minutes to allow the charge to migrate. A baby wipe does a good job of wiping down the external surface as you describe.

This idea was mentioned earlier in this thread. You don't want to connect to it with a simple cable and alligator clip though. Reason being your clip is at ground, your jug screw is at some positive potential, you have vapors present and this is a recipe for a spark and ignition. You will want your cable and clip to have pretty high (mega-ohms) resistance to ground so the charge is dissipated slowly avoiding a spark while getting rid of the potential difference.

If you have fuel in the aircraft sitting on a rubber sheet to prevent if from slip-sliding around you have insulated it from the aircraft and the two can develop a potential difference and therefore an explosion hazard. The static hazard exists whether the fuel and plane are in a building or sitting out on a ramp. In a building could have more issues even as the fuel vapors will not dissipate as rapidly.

MTV, your absolutely right. The laws of physics don't change. The problems discussed in this thread still exist. Like I stated before, it has been almost 4 years and I thought someone might have found better ways to deal with the problems created by self fueling with plastic gas cans.

A question? If I leave the plastic can sitting on the wing for 5 minutes would that equalize the static charge between the plane and can? The problem I see is, the plane is not in contact with the ground so you would need to fill from a non conductive ladder.

If a metal ladder is used you should have both the plane and gas can grounded right?

I don't know if I'm just lucky or what, but I have three 5-gallon plastic gas cans that I have been using to fuel my airplanes with for 15 years. No special grounding or static-equalizing procedures, and no problems filling or emptying. If I lived in a drier more static-y part of the country maybe I wouldn't be sayng that, but I don't so I am.

Hello Backcountry Pilots,

Plastic gas cans are a necessary evil in flying sometimes. I do plan to utilize them for a few legs on my trip to Alaska next summer. My plane only holds 40 gallons and in order to fly the Trench, and support my caribou hunt on the North Slope I need extra gas. That said, I intend to do it as carefully as possible by grounding the airplane and setting the can of the metal wing for a while allowing it to stabilize.

These new "no spill" California gas cans really suck! You can't hardly buy a real gas can with a breather anymore. I did buy four cheap "Enviro Flo" 5 gallon cans and modified them by adding a metal valve stem as a breather. Without a breather these cans will barely pour any gas. A guy could be up on the wing for 25 minutes with these "no spill" cans. My valve stem conversion really works!



Just my 2 cents.



James

I've made it a hobby to look for older style (read usefull) gas cans when in small town hardware stores, gas stations etc. The kind of places where they still sell hardware by the pound, not pre packaged in plastic bags. You have to get off the beaten path to find them but that's fun too. The new ones, and I can imagine how California has improved the design are just about useless for more then a gallon at a time unless your a weightlifter and like to feel the burn (bad anology).

Jaerl,

The fuel handling guys we worked with concluded that essentially nothing one could do with a plastic can would eliminate (at least to a reasonable level) the potential (pun intended) for a static problem fueling airplanes from plastic cans. They experimented with a section of hardware cloth INSIDE the can, with a section of hardware cloth bonded to the OUTSIDE of the can, with these pieces of metal clipped via wire to the fuel filler neck. There was still substantial residual static charge residing on the plastic can.

Point is, all these things may help a bit, but you have to understand the problem, which most users of plastic cans simply refuse to recognize: Plastic is an INSULATOR, not a conductor. There is a cable which connects the computer you're working on to a wall socket, presumably, right? What material is used to cover that cable, to insulate it from it's ground wire, and from your hand, so that you don't experience 110 v stimulation?? Plastic of one kind or another. That plastic can is also an insulator.

Now, in addition to being an insulator, plastic is a GREAT little material for STORING a static charge. We all remember the high school physics experiments where we rubbed our feet on a carpet, then touched the cute little blonde on the ear, arcing a spark to her petite little ear, and eliciting a squeal of delight in response to our cleverness, neh? That plastic can will build a charge quite well, from being moved through the air, on the ground, etc, etc.

Now, put the plastic can on top of your metal wing. Maybe a little bit of the static charge will dissipate, and that's not a bad idea, BUT, remember--plastic is an insulator. So, the static charge on much of the can remains.

Now, you start to pour fuel into the fuel filler. As someone noted earlier, fuel isn't a very good conductor either. Fuel sloshes around quite a lot as it pours. Remember our scheme for creating static to zap the blonde?? Moving our feet on carpet... Fuel moving inside that can helps to create a static charge.

If conditions are right, and the charge achieves a sufficient level, a spark can arc over from can to filler neck. That almost certainly will ignite the fuel vapors circulating around that filler, and you've got a fire that you are NOT going to extinguish.

And, folks, stop talking about GROUNDING. We don't GROUND an airplane when we connect the wire to the gas supply to fuel. We BOND the plane to the fuel container. And, that's what we need to do with a fuel can.

Look, I've fueled from five gallon plastic cans in past. I've always been as careful as possible when doing it, but I've also always assumed that I might get unlucky doing so. I don't use plastic cans any more unless there is simply no other way to get gas into the tank.

A friend who had a C170 with small tanks fabricated a set of aluminum fuel cans (four of them) for his plane. He was a hobby welder, and he used a mig welder to make cans that would fit in his float lockers. This was his primary goal, because the float lockers had small hatches, and none of the commercially available 5 gallon cans fit. His cans were a work of art. He used hardware store fittings for a spout and vent, and the things were as light as plastic. He glued some rubber onto the bottoms to protect the float lockers from sharp edges. Each can had a bonding cable, which he connected PRIOR to fueling. These things were simple, and according to him, weren't that hard to make.

And, I agree with James, the current crop of plastic cans make the problems worse, not better. They are so crappy as to be ridiculous in my opinion.

Again, you might get away with fueling from plastic cans for decades, and you can fool yourself thinking that you can dissipate the static charge on a plastic can, but there are folks out there who've lost airplnaes and people who've been hurt fueling from plastic cans. It's a crap shoot. Roll the dice.

MTV

If that Northern Hydraulics gas tank had the discharge spout twice the O.D., and a separate large vent, that'd be the way to go. Ever see how the pit crews at Indy do it? I don't know if moving more fuel quicker or moving less fuel slower is better or worse for static concerns, but I like to do it fast.

once&futr_alaskaflyer wrote:http://www.northerntool.com/shop/tools/product_200376069_200376069

Here is another problem with using the plastic cans:

http://www.cdc.gov/niosh/hid2.html

So from what I read here cold weather and dry conditions are the worst for using Plastic Cans right? Does anyone have actual data from actual testing?

Life is full of risk. Whether it is driving, flying or walking outside on a cloudy day. I have heard that flying a small plane is as dangerous as riding a motorcycle. That to me and probably everyone here, is an acceptable risk. What I am getting at is, how dangerous it filling with a plastic tank? Does it happen one time in a million, one time it 100 million times. And what can we do to minimize the risk?

I really don't want to quit self fueling but I was hoping not to burn to death either. Great thread and great info. I never knew the problem existed till I read it.

I am posting what it says on the bottom of the previous warning again in case anyone missed it:




[b]Safe Practice: Always place gas can on ground before refueling.
Touch can with gas dispenser nozzle before removing can lid.
Keep gas dispenser nozzle in contact with can inlet when filling.[/b]

Mike, I'd like to hear more about that blonde, her little ears, and the squeal of delight...

Jaerl wrote:Here is another problem with using the plastic cans:

http://www.cdc.gov/niosh/hid2.html

So from what I read here cold weather and dry conditions are the worst for using Plastic Cans right? Does anyone have actual data from actual testing?

Life is full of risk. Whether it is driving, flying or walking outside on a cloudy day. I have heard that flying a small plane is as dangerous as riding a motorcycle. That to me and probably everyone here, is an acceptable risk. What I am getting at is, how dangerous it filling with a plastic tank? Does it happen one time in a million, one time it 100 million times. And what can we do to minimize the risk?

I really don't want to quit self fueling but I was hoping not to burn to death either. Great thread and great info. I never knew the problem existed till I read it.

If it were an actual problem you wouldn't be able to buy plastic cans in the first place. It just doesn't happen.

Glad that's settled and now I can go fill up the plane!

No really, I did a search and most of the info is on Attorney's sites trying to get business from idiots that blew themselves up doing stupid stuff. Didn't find one actual case of static electricity igniting a gas can. Anyone got any confirmed cases involving filling of Aircraft?

I haven't been blown up by a plastic jug yet. I don't know of anybody that has.

james wrote:Hello Backcountry Pilots,
Plastic gas cans

These new "no spill" California gas cans really suck! You can't hardly buy a real gas can with a breather anymore. I did buy four cheap "Enviro Flo" 5 gallon cans and modified them by adding a metal valve stem as a breather. Without a breather these cans will barely pour any gas. A guy could be up on the wing for 25 minutes with these "no spill" cans. My valve stem conversion really works!

James

There are probably very few pilots up here in Alaska that don't occasionally (or often) use plastic fuel cans to extend their flying (or ATV, snowmachine) range. I've probably got 20 of the old plastic cans scattered among my various "caches." Unfortunately they are now all getting rather "long in the spout" and I am being forced to replace them with these miserable "Enviro Flo's". These things really suck. They pour at the rate of 30 degree molasses, and their unprotected spout make them difficult to safely transport.

I really like your air valve modification. Is that a self-tapping valve? What is the name of this valve and is it readily available in the local hardware store?

Glidergeek wrote:I haven't been blown up by a plastic jug yet. I don't know of anybody that has.

I do.

Bad philosophy.

Off the subject but if you haven't been to this site you should bookmark it. They have almost anything you will ever need.

http://www.mcmaster.com/#

Too bad the Mr. Funnel company doesn't also produce jerry cans out of the same stuff as the funnels

Zane
Not my philosophy, just a reply to Jeryl's question of do you know of anybody know of anyone hurt or blown up. I have done plenty of transferring into 55 gallon drums from plastic. Getting a partially filled drum out of a pickup is rather difficult so I'll use 4-5 5 gallon jugs into the drum. Then I use a pump (electric) to transfer into the plane. I have done the plastic jug in Mexico once, difficult at least, gotta find a ladder carry a 35+ pound jug up, set it on the wing scratch your paint and spill it all over when you tip it to pour. My MO is that the $.90 to $1 I've saved over the past 15 years has been enough to buy a 55 gallon drum ($20) and a Fill Rite 12 volt electric gas pump ($350) and filter and not wear the gas I'm trying to get into my plane. Certainly if you fly 100+ hours a year if you're using mogas or a mix you save enough to invest in an alternate and safer method to get gas into your wings than plastic jugs.