Gas, Cans, & Bonding
 

Newer member here. If this is already clearly covered in another thread, I apologize. I've been reading so many conflicting and unclear posts, blogs, and articles my head is spinning.
1. Originally, I thought in a Rotax 912 ULS I was going to have to run "Clear" - non-ethanol, high octane gas. After reading many things, including info right from Rotax, I now believe I can safely use AKI 91 w/ 10% ethanol. Is this correct?
2. Again, from reading many conflicting articles/postings, I am confused about the proper container to use in humping fuel to the airport: plastic vs. metal. I've read that the action of pouring gas through plastic creates static buildup that can jump to the fuel/air mixture when entering the plane. I've read that metal is safest and yet most pictures/videos/and even ads have plastic jugs being used.
3. Bonding: I cannot find any picture or video of someone demonstrating bonding their portable gas can to the plane. My CFI doesn't bother; he just pours directly from the plastic 5 gallon container into the plane.
4. Do most RV-12 owners recommend using Mr. Funnel, and if so, which model.
Thanks in advance! Jim

Jim,

I?ve heard accounts of static buildup on plastic cans too, but I?ve never encountered it in 6 1/2 years of fueling from ungrounded plastic cans. I do put a finger on some bare metal part of the airframe while holding the can before I pour in any fuel, but I?ve never felt any discharge. Out here in the dry Arizona desert I think I would have seen something if it was an issue. Maybe someday I?ll find out different the hard way, but in well over 500 fueling evolutions with the plastic cans (most involving at least two cans) I?ve had no static problems.

My can nozzles have a coarse filter in them. So far no gascolator debris at 6 annuals.

I?d gladly use a grounded gas pump if my FBO offered autogas, but in absence of that I?ll continue as I have been.

Rich

In response to:
1. 10% ethanol is fine and ultimately preferable to 100LL, although it too can be used albeit with some shortened maintenance intervals. I think I remember reading that Rotax says 15% ethanol is ok, but I?d have to look that one up to be sure.
2. I?m sure either is fine since they are both approved for fuel. I uae plastic 5 gal cans myself.
3. I don?t use any bonding when I pour the gas into the plane; however, I do make sure to take the jugs out of the truck and set them on the ground to fuel them up. Some newer trucks have a warning label inside the bed telling you to do that.
4. My jugs have a coarse screen inside the funnel. I don?t use any other filtering than that and haven?t had any issues
Just my experiences.....
Good luck

Same here... pour from Briggs & Stratton 5 gallon plastic directly into tank neck with no funnel. Poring spout on can has a course screen. 400TT using 93E10 and nothing ever found in gascolator bowl during disassembly for inspection. I have found debris when draining sump before daily flight - but very rare instance. The design of the gascolator bowl is self cleaning when sumped. The fine screen in the gascolator has never allowed any debris into the carburetor float bowls.

Some info for your consideration:

https://cafe.foundation/v2/pdf_cafe_...g%20Safety.pdf

Also, I have found the Mr. Funnel fuel funnel to be difficult to use due to the angle of the RV-12's fuel filler port -- it is also very slow flowing. In 680 hours of using primarily Auto 91+10% ethanol (Yuck!), I have yet to find any evidence of fuel contamination. YMMV.

Above link doesn't work...

The software strips out the %20 characters from the file name Fuel%20Handling%20Safety.pdf

Try using the right button to copy the URL and then paste in a fresh window.

I've looked into this in the past. There isn't really a way to discharge static in a plastic can as the charge builds up on the surface of the liquid. But they seem to be used everyday on boats, bikes, lawnmowers etc without much problem.

Have an extinguisher or fire blanket close to hand seems like a good idea.

Try this link:

https://cafe.foundation/v2/main_home.php

or GOOGLE: Cafe Foundation

I don't like lifting the 5 gallon cans up to the tank opening so I got a Flo-Fast pump and one of their 5 gallon cans. The pump has a grounding cable that I attach to the aircraft. I transfer the fuel through a Mr. Funnel into the pump can then use the pump to get it up into the tank. Works well and is pretty easy.

The Fokker warbird wannabe is even more awkward to fuel than the RV-12. Here is my fuel transfer rig that uses a 12vdc Carter automotive fuel pump driven with a retired PC680 battery:





This rig works great, flow rate is one gal/min. Just turn it on, step back and let it it pump. The fill nozzle is an aluminum tube which touches the fuel tank to dissipate static charge (photo shows grounding cable which is no longer used). The valve on the intake tube is closed after fueling to retain fuel in the pump so it won't have to prime next time it is used and eliminates messy drain-back.

P.S. My next-door-neighbor has an RV-12 and commandeers my fuel rig....and has retired his crank pump. :)

My practice is the same as Tom. I have a local station offering 91 octane ethanol free so I have portable tanks totaling 37 gallons and I use this supply as quickly as possible but if I have some left after six weeks the remainder goes in the car.

I do use Mr. funnel when transferring fuel to the Flo-Fast 7 gal tank I use to pump the gas into the plane. The pump system also has a fine screen filter at the end of the pick up tube. My last check of the gascolator did have some debris on the screen despite my filtering efforts, but this is why I check at least annually.

If you go with Flo-Fast, I'd definitely recommend the Professional model instead of the Premium model. I started with the Premium and kept getting leaks around the handle shaft. The Pro model is more robust. It has a three vane pump - pumps a bit faster than the Premium - 10 rotations/gallon. No leaks yet.

As long as we're talking about transferring fuel... I use these eBay EZ-Pour Hi-Flo spouts on a 5-gallon Briggs & Stratton plastic fuel can.

Pretty much like an Indianapolis pit stop... never timed it, but I guess can empties in 30 sec.

We run 91 ethanol-free, because it's available close to the airport. We have a total of 5, 5-gallon plastic gasoline cans we use to transport from the gas station. Since I've had no trouble using plastic gas cans for everything else over the past 30 years or so, I'm not particularly concerned about static arcing during fueling. Use common sense, touch the plane and can before fueling, etc.

We've run 91 ethanol-free, 92 E10, 100LL, and Swift 94UL. No detectable change in starting, running or performance with any of them. We typically avoid E10, just because we can and the straight gas won't absorb water as readily... or so we're told. 100LL is the last resort, or we'll pour in a couple gallons of the plane has been sitting for more than a couple of weeks with mogas in it.

I have a large Mr. Funnel at the hangar. If we have any uncertainty at all about the fuel age or quality, or just for the heck of it once in a while, we'll use that to transfer a full can to a known clean empty one. On rare occasions we'll use it while fueling the plane, but generally not due to the angle of the filler. I also use it any time we drain the tank. We've never found water in the gas, and rarely any other debris. The only thing I've found in the gascolator in the past 3 years of annual inspections was what appeared to be a single cottonwood seed last time. Don't know where that entered the fuel system, but some times of the year here the cottonwood seeds fall like snow here.

Used Walmart 93 octane premium for hundreds of hours with the Rotas 912S 100HP engine. At 1200 hours pulled the gear box for R&R and it had no Lead paste what so ever. Also never found any lead paste or sludge in the oil tank under the baffle. 100LL is the least acceptable approved fuel. Premium auto with no alcohol is the best but even with alcohol it is good if the aircraft's fuel system and hoses are alcohol safe.

Nice rig, Sam!

Thanks to all...
 

Thanks to all of you for your counsel... much appreciated. I suppose a person could worry this stuff to death, just trying to be careful.

I also found this a bit troubling: "A 'premium' fuel will see its octane rating reduced to unusable levels after as little as three weeks." And later... "To be avoided: 'Premium' fuel which is more than 3 weeks old." Source: http://www.rotaxservice.com/rotax_tips/rotax_feed4.htm

If accurate, with a planned fuel burn of 5.6 gph and 20 gallons, a person needs to be flying a bit more than 3.5 hours every three weeks to avoid inviting pre-ignition and detonation. I guess the alternative is to drain fuel and use it in your car.

I'm beginning to wonder if I read too much.:confused:

Don't fill the tank to the top...only add whatever fuel you anticipate using in three weeks....or add fuel for just the next flight. What am I missing here??

How long does it take to turn those 10 rotations and pump the gallon? I picked up a few 10 gal FloFast jugs on sale, now trying to decide between the hand pump or a DC pump rig on a cart.

I'm sure that Rotax has good reason to be that conservative in their recommendation. However, I can say from experience that E-free premium mogas works well in a 160 hp (higher, 8.5-1 compression) Lyc when it's a lot older than that. The biggest downside I've seen is that if fuel sits in the carb's fuel bowl (small volume, high surface area) for more than a few weeks, the engine will be very hard to start. Since auto fuel has 'aeromatics' (?) that enhance starting ability, my totally unqualified opinion is that those components flash off a lot more quickly than the rest of the chemicals in the gas. My experience in a situation where I haven't flown for several weeks is that a half hour or so before next flight, I can exercise the throttle repeatedly, using the accelerator pump to mostly clear the bowl. I then use the boost pump to re-fill the bowl. The engine has always started quickly since I began using this method.

More when I'm awake.

Charlie

:D +1 Flo-Fast system

I never thought about that, but the Rotax has a leg up here. Consider this scenario… airplane is done flying and put away hot, which is pretty much always the case. Latent heat under the cowl heat-soaks the carbs until the engine returns to ambient temp. So the fuel may well volatilize in the carb bowls and vent the fuel vapor out the overflow tubes. No problem, and in fact, a good situation. Now, when the airplane is powered for next flight, the electric Facet fuel pump will recirculate and deliver fresh fuel (with correct octane) to the near empty float bowls. Always an easy engine start with no detonation from deteriorated fuel.

Here's a shot of our Flo Fast set up. Use to fill the Rans S-7. Works very nicely.

Here is my Flo-Fast in action. Don?t know how many turns per gallon but it only takes a few mins to fill the tank. Easy Peasy

I don't know, maybe 5 or 6 seconds. 1/2 minute or so for 5 gallons. It's not strenuous either, it's a pretty easy pump.

Just out of curiosity, what's the pump body material? Functionally, it looks very similar to
https://www.harborfreight.com/dual-d...ump-40844.html
which says 'not for gasoline', but that's their lawyers talking. One of those worked great to transfer avgas from our airpark tank to our generators during the aftermath of Katrina. Worst thing for portable use is that it's cast iron and not light.

I?ve only experienced one issue with ?old fuel?. I let a tank sit for 4 weeks during a long summer vacation and when I flew I experienced some pressure surges due to vapor bubbles in the fuel line. When I switched on the electric pump the fuel pressure stabilized. Usually my fuel pressure is fine with just the mechanical pump.

I counted 65 turns for five gallons.

Not sure. The body is not metal so some sort of plastic with a metal handle. The Professional model seems durable enough. As I said earlier, I had problems with the Premium model leaking through the O-rings on the handle shaft.

That HF pump is a barrel pump and, as far as I know, won't fit any gas can I know of. Of course, if you have a barrel ...

The Pro model is a 3 vane pump vs 2 vane with the Premium model so it pumps faster.

Ground while refueling
 

I also use the Flo-Fast Pro pump. It comes with a static ground wire attached and I use it. The pump static wire gets attached to the tail tie-down. I also have an aircraft ground cable attached to the tie-down which attaches to the hangar ground.
You can't be too safe refueling with gasoline, ya know;)

Where should the fuel rig be grounded?
 

The question for which I haven't seen the answer is "where should the ground wire be attached on the fueling rig?"

Does static need to be discharged at the pump or at the nozzle where gasoline enters the aircraft tank? It seems to me grounding should occur at the nozzle to eliminate static buildup as gasoline flows through the delivery hose post-pump. Is having the grounding cable at the pump leaving part of the system unprotected?

Before anything else, I should say that a good friend of mine actually had a fuel fire while fueling his -6A from cans. He was fortunate; it did no damage. He had fire around the filler neck (quickly extinguished by dropping the cap into the fill neck), and a small fire on the ground due to spilling some of the can's contents as he recoiled from the fire. He will no longer fuel his plane except from an airport pump.

With that out of the way...

If I'm not mistaken, commercial pump hoses are bonded from nozzle to pump. Having said that, I suspect that if you fail to attach the ground line to the plane, and hold the nozzle over/in the fill neck without actually touching the neck, you could still get static buildup. I think this because it's my understanding that the fuel's flow through the hose can generate static charge buildup, similar to rubbing your shoes on carpet.

Having said all that, I'm pretty sure that plastic gas cans are impregnated with enough conductive material to bleed off any static charge, as long as they are in contact with ground or the source/destination of the fuel. And if you can believe the Gubmnt, metal is no help. See the last sentence in the 2nd paragraph. Also note the recommended procedure to minimize risk while transferring fuel in either direction.
https://www.cdc.gov/niosh/docs/98-111/default.html

Last, IIRC, the reason I was told to hook up the ground lead before getting the hose at the fuel farm was because the plane itself has the potential (pardon the pun) to build up a static charge in flight (think static wicks on high/fast planes), and there's a risk it could retain that charge as you approach it with the grounded fuel hose.

I continue to fuel from plastic gas cans; I just try to incorporate whatever new info I learn as time goes by.

Charlie

edit: Should have added: Touching the can to something metal on the plane before opening either fuel container should dissipate any static charge differences between the fuel and the plane.

Any static spark would occur at the first contact point. If the component that makes that contact is grounded to any part of the airframe it should be at the same electric potential so know spark would occur. So it doesn?t matter where you pick on the airframe to connect the ground wire as long as it?s not insulated from the airframe. In practical terms that means don?t pick a painted or nonconductive surface, but exhaust pipes, unpainted tiedown rings or unpainted nosewheel forks are good choices. The other end should have a conducting path to the fuel nozzle.

I was not as clear as I should have been. By "fueling rig", I'm referring to the ones that have appeared in this thread with either electric or hand-crank pumps. The aircraft end of a grounding scheme should obviously be connected to a conductive surface, but where should we connect the other end of a ground cable. To the plastic can, or a probe in the fuel, or the pump, or at the nozzle? Is it sufficient to have a conductive nozzle that is in contact with the metallic aircraft tank?

I am inclined to think the metallic nozzle would bleed off any charge created by movement of fuel in the system, but am wondering if I am overlooking something.

Wow, Great Fueling Info
 

The only airport I could but high octane non ethanol fuel quit selling it for lack of volume. (Arlington Flight Services KAWO) As far as I know the nearest on airport fuel is over 200 miles away and so same problem. I can purchase from a Cenex gas station about 10 miles away. What a hassle.

I'm at AWO. I run 0-E in my Sonerai. Nelson's is about 1.5 miles from AWO, and they have 92 octane 0-E. And, its cheaper than what AFS was selling it for on the field. Also, River Rock Smoke Shop, on Smokey Point BLVD has 89 octane 0-E.

For those of you that haven't discovered it yet, check out https://www.pure-gas.org.

Also, for those of you that can hoist a gas can and don't like the one-gallon-per-minute gas pump rigs, nor the "Safety-can" style ****, you can still buy the old utility jug used by dirt-bikers for years.

https://www.amazon.com/VP-Racing-Squ...gateway&sr=8-3

Touching airplane and jug before and during fueling, never had a static issue.

I have a wire cable with alligator clamps at each end. I attach it to my tail tie down ring and the other end I either let lay on the ground or attach it to a tie down point if near one. That should discharge any built up charge and keep it attached while fueling using plastic jugs...works for me.

Don?t want to insult anyone by stating this, but the purpose for the BONDING cable is to bond the airframe to the fuel dispensing nozzle. Fuel flowing through the hose and nozzle can develop a static charge. Electrical current flows from high to low potential. If both the airframe and nozzle are at the same potential (via the bonding cable), voltage won?t build up between the nozzle and filler neck, thus no static discharge. The hose on the fuel truck, or airport stationary fueling pump, has an internal bonding wire that connects the nozzle to the chassis ground on the pump, which is connected to the retractable bonding cable on the pump. So, one ideally wants to connect the bonding cable between the airframe and fuel filler nozzle, or as close to it electrically as one can get.

When you fill up your car there's no bonding cables used, although nozzle is metal and your usually putting in 20 gallons or more in some cases. There are warnings about static discharge so either its a rare occurance and we're just lucky I guess...

Racing gas cans
 

I got no skin in this game because I plan to pump but at some point I will be moving fuel to test fuel flow, etc.
Does anyone use racing gas cans? They dump gas really fast. We used them for years refueling the race car. No grounds, no bare hands touching anything. Fully covered with racing gear. Maybe every team was lucky, but I never saw a fire on pit row. Maybe they are made for it?