In a recent email, a pilot related a problem he had with his aircraft: He needed to drain the fuel tanks so that he could repair the wing.
He drained the 100LL out of the tanks into two plastic drums. The fuel sat in his hangar for several weeks and then outside in the sun for several more.
When the repairs were done, he started to return the fuel to the aircraft and noticed that in one drum the fuel color had changed from blue to tan. He tried the other drum and it was still blue. But when he got down to the last few gallons, that fuel was also tan.
He drained the last few gallons through a filter, and it left a tan coating on the filter.
He asked what happened and what should he do.
Well, the what happened was easy: With the help of the sun, the fuel leeched out the plasticizer in the drum.
The hard part is what to do. I can say with about 81.65% certainty that it should not be a problem.
But in aviation that is not very good, so I recommended he drain the fuel and then flush the tank until no film is noted on a filter.
A plastic is defined as “any of various nonmetallic compounds synthetically produced by polymerization.”
There are literally thousand of different plastics with a wide array of different properties. Some are soluble in hydrocarbons like 100LL and others, like those used in plastic gas cans, are much less soluble.
If you are going to use a plastic container to hold fuel, you need to make sure the container is meant for holding fuel.
Even in these containers, fuel will leech out some of the plasticizer, but generally not enough to affect the performance of an engine.
If you use a plastic container designed for use with fuels and plan to store it for any length of time, do not store it in direct sunlight or find a metal container.
For example, all of our safety procedures state that if samples are drawn after an accident or event, never store the samples in plastic containers. This is because even in plastic containers designed for fuel use, the fuel will leech out enough plasticizer to affect many of the sensitive tests run on fuels to determine if the fuel was instrumental in the problem.
Safety Fuel Containers
While I am on the subject of plastic containers, I would like to get on my soap box and talk about the new unsafe “safety fuel containers.”
I am a volunteer firefighter and recently we were doing a control burn of an old house. We had cut a bunch of trees down before the burn and after the house had fallen, the owner asked if we would cut the trees up and throw them in the burning basement.
We got our chainsaws out and cut them up and threw the wood into the fire. When we got done, I noticed the saw I was using was almost out of fuel. We had an old regular type fuel can but it had started to leak, so we bought a new one.
The new one was a “safety can” with the new safety spout. To use it you need to catch the little plastic tab on the spout on the edge of the tank of the saw. Well the tank was not deep enough to get the tab to catch, so I had to hold the spout in to fill the tank.
Needless to say, by the time I got the tank full, my gloves were soaked in fuel and I had part of my bunker gear soaked.
Now I am at an active fire scene soaked in gasoline. Not a good thing, so I changed gloves and hosed off my bunker gear.
This got me to thinking about why they would outlaw a normal spout that has worked well for many years and force us to use a piece of junk that doesn’t work worth a damn and is very unsafe.
I figured that somewhere there is a government employee who needs to justify his or her existence, so this person found a case where some idiot may have spilled fuel while trying to refuel their running lawn mower and started a fire. The government employee knew that it was necessary to protect the public from themselves, so he or she came up with a standard for a “safety can.”
It probably has reduced accidents because people have switched to electric mowers and trimmers because they could not get their gasoline-powered tools fueled. But for those of us who have enough smarts to pour water out of a boot even without the instructions needed on the heel, these spouts are a safety hazard and are junk.
On the positive side, the new standard has created several jobs in China for guys to build the new unsafe “safety cans.”
And it has created a new underground industry with more manufacturing jobs in China to build regular spouts or safe spouts that do not meet the unsafe “safety can” spec.
Is this a great country or what?
Tuff Jug. Best gas can for aviation.
Consider how many boats are fueled on the water with these new “safety” cans and how much MORE fuel ends up in lakes, rivers and oceans because of them.
You can’t fix stupid with more stupid.
“I figured that somewhere there is a government employee who needs to justify his or her existence…”
Nailed it right there, Ben. ‘Nuff said.
Tan 100LL aircraft fuel: Exact same event happened to me 2 months ago. To rebuild a leaking fuel valve in our C210, the fuel tanks were drained into newly purchased red plastic 6 gl containers. Within 2 weeks the fuel turned a tan color. Storage was inside. The family car ran fine on this fuel. Thanks for the insights on why the fuel discoloration. Ditto your comments on the tank valve designs.
Never use a plastic gas can for aviation fuel. In this case the guy should have transfered his fuel into another plane. If you are gonna use avgas in your plane get a DOT approved transfer tank and fuel pump….place it in the back of a truck or on a small trailer.
And if you are gonna store fuel for lawnmowers and weed eaters at home use small cans and buy a gallon at a time. You should not keep the fuel for longer than 6 months even if stored in a cool, dry, shaded place.
The new cans are part of a wide range of regulations put into place by the EPA. The whole reason is to prevent the permeation of fuel/ vapors from vented fuel containers and open vented systems. The new cans are not vented to the outside air. All marine portable fuel tanks are also produced without vents.
The effect of this is when left in the sun or a hot compartment the tanks swell. This pressurizes the fuel in the tank and lines going to the carburetor. The fuel then is pressurized more than the inlet needle, float, can handle and the result is a bunch of raw gas inside the engine compartment and in the water!
So much for preventing vapors into the air from a vented container.
The EPA also changed the permeation standards of fuel lines causing the price of fuel line to skyrocket. The standards also caused a redesign and experimentation on the public by hose manufacturers. This has led to collapsed hoses, hoses with deteriorating liners clogging the hose and many blown engines!
Until the EPA is sued and a big court case, the rules will stay and a lot more fuel will be spilled and vehicles and boats ruined, catch fire, blown engines will continue. All to save some vapor. Which when the fuel spills pollutes 1000% more than ever before!
A disaster that is happening!
Finally wonder why the fuel tank you used to buy for $9.95 is now $39.99? Blame the EPA.
Disclaimer I am not anti-EPA. Just anti stupidity.
And while we’re on it, Ben … how about the idiot who redesigned the filler fittings on propane cylinders. While not as problematic as the new fuel can spouts, they required everyone to go out and buy new tanks. Great deal if you’re a propane cylinder manufacturer but not so good if you have a bunch of ’em that needed replacement. SAY … doesn’t the situation you describe also apply to the FAA? 🙂 There are several new NPRM’s for AD’s that have come out that are there because some FAA guy found one or two airplanes with an issue. BIG SIGH!
You can’t regulate STUPID
I totally agree. The worse spouts I ever used, not to mention slow to pour. Fortunately, I have been able to mostly eliminate the need for gas cans later in my life.
The new “safety” cans have got to go. I can’t remember the last time I got a successful transfer of fuel from the can to the target tank. I always spill multiple ounces trying to get it to work.
I recently had to refill an old Alfa Romeo that had run dry wtih a new fangled 10 gallon can. I’m pretty sure I got at least 8 of the 10 gallons in the gas tank.
And it’s illegal to retrofit an old style spout. No win situation.
Hopefully this will be one of the regulations they repeal.
That article is so true. If anyone used common sense he
probably get arrested