Rules for using MOGAS?

Shepherd

Shepherd

Final Approach
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Shepherd
My PA-17 has the mogas STC. The previous owner ran almost exclusively on it.
Unfortunately, mogas has NEVER been available in my area, so I have never used it.
Never been available, that is, until this week. The station down the street now has it.
I have qty 3, 5 gallon, VP Racing containers. I also have a hand pump and an electric fuel pump that I could use to fill the plane.
Any "rules" for using mogas?
Any wisdom to impart?
 
Whatever you do, do it outside, not in your hangar.

Fuel running through a plastic spout creates static electricity. Static electricity can create a spark. Spark+fuel can be bad. This is more likely to be a problem on cool dry days (low humidity) than on days with lots of moisture in the air. Before you begin pouring fuel from a plastic container, ground the container and the fuel stream to the aircraft you're refueling to make sure the fuel can, fuel, and airplane have no electrical potential difference between them.

Check with the locals to make sure you don't get crossways with any self-fueling regs at your airport. They have to allow it, but can create rules that make it onerous.
 
Every load you get, check to make sure it doesn't have ethanol in it. Don't go by the pump label. Testing is quick and easy.
alcohol check ethanol.JPG
You don't need a big sample, the important thing is the relative level of the water to the fuel after shaking things up. I bought a couple of small test tubes from Amazon, came with rubber stoppers. I have the line pre-drawn on the tube....fill with water to the line, add fuel, stopper it, and shake. Results are pretty fast.

I test every load.

Ron Wanttaja
 
wanttaja said:
Every load you get, check to make sure it doesn't have ethanol in it. Don't go by the pump label. Testing is quick and easy.
View attachment 110068
You don't need a big sample, the important thing is the relative level of the water to the fuel after shaking things up. I bought a couple of small test tubes from Amazon, came with rubber stoppers. I have the line pre-drawn on the tube....fill with water to the line, add fuel, stopper it, and shake. Results are pretty fast.

I test every load.

Ron Wanttaja
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I use one of these ...

proxy-image


$6.95 from Spruce
 
wanttaja said:
Every load you get, check to make sure it doesn't have ethanol in it. Don't go by the pump label. Testing is quick and easy.
View attachment 110068
You don't need a big sample, the important thing is the relative level of the water to the fuel after shaking things up. I bought a couple of small test tubes from Amazon, came with rubber stoppers. I have the line pre-drawn on the tube....fill with water to the line, add fuel, stopper it, and shake. Results are pretty fast.

I test every load.

Ron Wanttaja
Click to expand...

Interesting

I do similar, when I use mogas- but I use water based food color. I put a bit of gas in a 20oz pop bottle, put some food color in and give it a shake. If there’s ethanol in it - the gas will color, if the food color is in beads then it’s good.

same concept different route…
 
I fill with small gas cans, so I use a Mr. Funnel to filter the gas.
 

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Cluemeister said:
I fill with small gas cans, so I use a Mr. Funnel to filter the gas.
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Yes, I do too. I use 2.5-gallon plastic cans. Two of them fit in a plastic "milk crate," the crate itself rides nicely in the trunk of my car without letting the cans tip over. Mr. Funnel goes into the tank neck, and I hoist each 2.5 gallon can over my shoulder to transfer. 15 pounds is easier to handle this way than 30 pounds. I ground the bejesus out of everything, too.

In my case, 5 gallons of gas is an hour's flying. My solution wouldn't work for planes that burn a bit more gas.

Years ago, a friend took a manual bilge pump and set it on a wooden stand for using 5-gallon cans to fill his airplane. Took him ~30 seconds to transfer the gas from the can to the airplane.
fuel bilge pump2.jpg
Finally, remember that even if your engine is cleared for unleaded car gas, it was originally designed for 80 octane leaded fuel. Some parts still may want to see SOME lead. 100LL has four times the lead of 80 octane, so adding avgas for every fourth fill might be a good precaution. If you're flying cross-countries, you're going to see that anyway....

Ron Wanttaja
 
Good stuff.
Thanks for the tips.
I do the water trick to separate out the water/ethanol out of my gas then use the gas in my lawn mowers et al.
 
I’m using the swift ul 94 when available .haven't tried the non ethanol auto gas yet .
 
The VP racing jugs work great. They actually hold more than 5 gallons. Even accounting for expansion on warm days, I can easily fit 6 gallons in each one.

I hoist them up and fill the 10gal tank on the Sonerai no problem. 1 caution: be careful threading those danged spouts into the caps. I put a touch of Fuel Lube on the threads of the spout and carefully tighten them just snug, not over-tight.

Other than the POH supplement that should've come with the STC, there's no rules. I would be careful about running the 87 octane lawnmower gas that a lot of the places sell. If that's all you can get, maybe blend it with 100LL. I would think the 92 octane should run just fine though.

I test the MOGAS that I buy regularly. So far, I've never found any hint of water/ethanol.
 
When I did it in a previous 0320 I tested every batch with a test kit from eBay. Often my mogas(91 octane) never went beyond 50% mix with the 100LL. I never really tried to keep it as such, often just took 10-15 gallons at a time over to mix in.

If I felt the plane wouldn’t be flown a whole lot in ensuing weeks & months, I’d normally let the 100LL % get higher. Of course the STC’s assume it’s mogas at 100% all the time, or could be.

Just some things I did, not necessarily means a whole lot.
 
wilkersk said:
The VP racing jugs work great. They actually hold more than 5 gallons. Even accounting for expansion on warm days, I can easily fit 6 gallons in each one.
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I second the plastic fuel lugs. I have been using these same jugs for over 20 years now with all kinds of liquids and dry granular material. IMO they are safest way to haul fuel in small quality. Yes they will hold 6 gals easy. I do not fuel my plane in the hangar anymore. The spout is the way to go, I don't spill a drop.
052_7.jpg
 
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The Tractor Supply Fuel Transfer Pump ($35) works quite well.

Switch failure is easy repair.

Whatever system you use assure:

CLEAN ( really clean) containers

Good grounding system..


I know one guy was fueling left tank of C-150 with sun soaked mogas. He noticed FLAMES in the fuel Filler Port. His left HAND covered the port to suffocate the fire while he threw the can with his right. The can bounced off the right wing tip.
No grounding system!
 

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Magman said:
Good grounding system
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Bonding the airplane electrically to the fuel container is very important to avoid static discharge. Grounding is not necessary, or particularly helpful.

The problem with plastic containers is that they generate MORE static electricity during use, but are typically much more difficult to bond electrically to the airframe. Some creativity is often required.

Paul
 
Being in race country, the VP jugs are ubiquitous. You see the dirt biker racers and the like filling their jugs with 100LL at the airport. When I was recalibrating the fuel guages in the Navion, I had my jugs plus I borrowed four or five from a neighbor so I could drain and refill a 40 gallon tank.

They're calibrated to 5 gal, but will hold a bit over 6.

As pointed out, fuel falling through air WILL build up static. Always take care and fuel/defuel outside. I personally know of two aircraft destroyed in defueling incidents.
 
Another thing I like about the plastic fuel jugs besides no rust is they are easy to clean out with a pressure washer. You can get to the whole interior because of the wide mouth. Then you can air dry or if you have any methanol around from say racing, then you can swish a few ounces around inside and it will immediately dry out the inside. Methanol evaporates quickly and can be dumped out almost anywhere and it is gone.
I have used many jugs for many years and have never had a static risk using them.

IMO pouring through a funnel is asking for trouble.
 
Gary Ward said:
I have used many jugs for many years and have never had a static risk using them.
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Not sure I understand this statement. How would you know if you had a static risk? IMO, there is always a risk of creating a static charge when pouring large quantities of fuel out of a plastic container.
 
My advise would be to think about static every time but don't over think it. I've been fueling from the same Craftsman 5 gallon red cans for over 30 years. Always touching the airplane with my hands, elbows as I climb up. I use an 18" piece of hose attached to the can and pour straight in. As far as lead, I maybe run 100LL 2-3 times a year. I don't ever think about adding lead to the mix.

As a reference the old C85, Continental cylinders ran its last 900 hours with upper 70's compression, no problems. New C85, ECI cylinders ran 700 hours at 78-79 compression until I sold it.

Be Safe,
Anthony
 
kyleb said:
Not sure I understand this statement. How would you know if you had a static risk? IMO, there is always a risk of creating a static charge when pouring large quantities of fuel out of a plastic container.
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Your right, that don't sound right.
Knock on wood, we have never experienced a accident or fire from using plastic racing jugs. Did a lot of racing over the years and was around a lot of racers using the same type jugs and have never heard of a problem with static sparks using them.
Not saying it is impossible...
 
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Shepherd said:
My PA-17 has the mogas STC. The previous owner ran almost exclusively on it.
Unfortunately, mogas has NEVER been available in my area, so I have never used it.
Never been available, that is, until this week. The station down the street now has it.
I have qty 3, 5 gallon, VP Racing containers. I also have a hand pump and an electric fuel pump that I could use to fill the plane.
Any "rules" for using mogas?
Any wisdom to impart?
Click to expand...

Shep, you’re in NY, right? Find a local Stewart’s Ice Cream/Gas station in your area. 99% of them have 91 octane no ethanol unleaded. I use it religiously in my Sling, except in the winter when the plane may sit for longer than usual time due to the weather. Then it gets topped with 100LL.

I test a batch of fuel every so often and in 4 years, haven’t found a spec of water.
 
I know my "Mr Funnel" was advertised as having conductive plastic. It's a pity that plastic fuel cans aren't apparently the same. Still, I attach a cable to the fuel neck, plastic can, and funnel when I gas up.

Ron Wanttaja
 
kyleb said:
Not sure I understand this statement. How would you know if you had a static risk? IMO, there is always a risk of creating a static charge when pouring large quantities of fuel out of a plastic container.
Click to expand...

Static electricity is not well understood. This is an older video but very good:

 
OK, I'll ask - how are you grounding your plastic jug to the airplane? I was going to get one of those jiggly siphon thingies to transfer gas from the plastic gas can to the gyro (like almost everyone I know has done). I've never seen anyone ground their aircraft when doing this.
 
How to you ground something that is non-conductive?????
 
Personally, I went with metal cans so I can bond them to the airframe.
One less thing to worry about.
 
Pinecone said:
How to you ground something that is non-conductive?????
Click to expand...


With a conductor.

Plastic can hold a static charge (“static” means it’s not moving). A conductor will allow that charge to flow and neutralize. Two objects joined by a low-resistance conductor will be brought to the same electrical potential so there can be no spark from one to the other.

Essentially, you’re causing the charge to move through a wire instead of through the air (a spark).
 
Pinecone said:
How to you ground something that is non-conductive?????
Click to expand...
Dust collection systems in woodshops often use plastic pipes to connect the dust collector to the power tool. One simply runs a copper wire through the pipe, and bonds it to the tool on one side and the dust collector on the other. This nicely mitigates the risk of static-induced wood dust explosions.

In the diagram below, there would be a copper wire running inside every tube, connecting all of the hardware.

Diagram-System-Top-View-Blue-1024x348.jpg
 
How should I ground my "rotationally molded polyethelyne fuel tank" to my plastic 6 gallon fuel cans?

When I fuel at an airport I always use the grounding strap connected to the exhaust but does that ground the "rotationally molded polyethelyne fuel tank" that is in the plane? There was a Challenger II LW that caught fire some years ago. The owner stated the fire started inside the Mr. Funnel he was using ...
 
Interesting video you posted Dale, Thanks. That would be cool working on those experiments back in the day.
Everyone should watch it.

For me when I do use those plastic jugs, once I set the plastic jug on the wing (don't pay no attention to that towel in my picture above) it becomes charged the same as the fuel tank and plane. Then the risk of static sparks are greatly reduced. I don't feel a bonding cable is needed.
I tip over the plastic jug with the flexible spout in my hand that I guide into the fuel opening leaving the jug laying on the wing saving my back. Open the vent and the fuel flows into the tank quickly. The spout is inside the tank by 10-12" maintaining contact with the fuel tank. The fuel free falls only for a short while until the spout is covered in fuel inside the fuel tank. Fuel free falling thru the air can cause static sparks.
If your back is strong enough to hoist the jug up on the wing, then there is no safer way of doing it when using gas cans/jugs. IMO

Pouring into a funnel adds to the risk...
Temporary pumps and battery powered siphon pumps like shown above also add to the risk of sparks.
 
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I normally transfer fuel via a siphon hose from a 5 gallon plastic can. The can is placed on a short ladder adjacent to the wing (low). After reading this thread, I might have to rethink this method.
 
C-1 PILOT said:
I normally transfer fuel via a siphon hose from a 5 gallon plastic can. The can is placed on a short ladder adjacent to the wing (low). After reading this thread, I might have to rethink this method.
Click to expand...

That's how I always see it done.
 
All this fear of ethanol

Does anyone realize that the FAA ran a Cessna for 10 years with 100% ethanol and the only issue was needing to rejet thr carb?

The engine was super clean (no lead or varnish) and made more power than avgas.

10 years, nota single problem. Yes somehow ethanol is bad
 
pfarber said:
All this fear of ethanol

Does anyone realize that the FAA ran a Cessna for 10 years with 100% ethanol and the only issue was needing to rejet thr carb?

The engine was super clean (no lead or varnish) and made more power than avgas.

10 years, nota single problem. Yes somehow ethanol is bad
Click to expand...

they probably ran it every day. When you have ethanol in the fuel, when moisture and water gets into the tanks, the ethanol grabs the water and then phase separates from the gasoline.
 
pfarber said:
Yes somehow ethanol is bad
Click to expand...
Had a buddy that had an engine failure shortly after takeoff due to E-10 reacting with his "aircraft quality" fuel lines. (He wanted to build it "right"...)

OTOH, I run regular E-10 all the time with no problems.

You gotta know what ya got.
 
midcap said:
they probably ran it every day. When you have ethanol in the fuel, when moisture and water gets into the tanks, the ethanol grabs the water and then phase separates from the gasoline.
Click to expand...
If they were running straight ethanol (hard to cold start...) you aren't going to get phase separation. That's just a problem with gasoline / ethanol mixes. One that VERY rarely shows up in real life.
 
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kyleb said:
Not sure I understand this statement. How would you know if you had a static risk? IMO, there is always a risk of creating a static charge when pouring large quantities of fuel out of a plastic container.
Click to expand...
There's a static risk pouring fuel PERIOD. This is why draining fuel even into metal drain pans is problematic. The thing about metal cans however is that it's easier to mitigate the problem (but that doesn't mean they aren't there). Metal cans are easier to work around, but can be as dangerous if you don't do it right.
 
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