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Fuel Sample Question

Tacco

Well Known Member
How much ?stuff? , i.e. particles and other debris, are you finding in your fuel samples?
 
It's been a while but I seem to remember some very small particles for quite some time after I first started flying mine. For a long time now, though, none.
 
None, not even at the start.

Get a big red funnel with a screen in the bottom, like this, and drain your tanks.
Be sure to ground everything before you start!
 
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I use a use a Mr Funnel to filter the fuel from the gas station when I put it into a flo-fast container. The Flo-fast pump has another, pretty fine filter screen on it as well. Some of the particles look red, like rust.
 
None visible in the fuel tester. The most I've seen in the gascolator screen was what looked like a cottonwood seed or something. THAT would have caused a bad day had it made its way to a carburetor, I'm sure.

I should get better about using the Mr. Funnel... I'd love to find a good way to mount it to the plane so using it to fill the tank wasn't a two-person job.
 
110 hours in 14 months, about 530 to 550 gallons through it, and nothing. No water, no particles, no rust, nothing.

93 with ethanol mogas Fuel is bought at local Costco, they turn a tremendous volume of fuel there daily, and put in 6 gallon plastic type jerry cans. Looking at the fuel gauge on the tank it's pretty easy to see if 8 10 or 12 gallons of fuel is left in the tank, and what's needed to get it close to full with 20 gallons.

With all the Premium here in CA having ethanol in it, and my samples indicate at most 4 to 6% ethanol, we don't store gasoline, at the most a week or two, usually not at all. Buy it, bring to plane, fill plane up, and then go fly and burn it up. Going through 20 to 35 or 40 gallons per month. Plenty of turnover.
 
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I never see anything in my samples. I saw a tiny bit of particulate in my gascolator at first annual. Coming up on my 8th annual and have never seen anything more in the gascolator.

I helped a new SLSA owner who saw some debris in his sample. When the gascolator was open we found about ten small pieces of thread sealant. Looks like whoever made the threaded connections was not careful about contaminating the three end threads with the sealant.
 
Been using a Flo-Fast pump for 5 years now and I don?t believe the pump has introduced any debris. I also follow their instructions asking for oil to be put through the pump. I use a small amount, maybe 2 ounces, of marvel mystery oil, and let it run out the pickup tube as I turn the pump. I do this once or twice a year.
 
OK, full disclosure here since you?ve hit on a sensitive topic that has caused an awful lot of frustration and embarrassment.

My RV-12 was down for maintenance, SB upgrades, and paint for over a year, finally getting it back in the air last August. Looking back, I did almost everything wrong with regard to refueling. Metal 5-gallon gas cans sat empty for 18 months. 93 octane ethanol free gas was purchased from a rural gas station that didn?t sell much gas. No filtration was used as this filth was poured into the empty tank. Within no time at all, my gascolator samples were full of enough debris to entirely cover the bottom of the sample tube. The gascolator screen was packed and fine debris made its way to the carb bowls.

With an attitude of total denial regarding the seriousness of this problem, and a refusal to remove the fuel tank again, I disconnected the fuel line from the gascolator to the engine and began pumping fuel from the tank through the gascolator into clean plastic cans. The flawed logic was that I could flush out the debris from the tank, check it with the gascolator samples, and pour the same fuel back into the tank through a Mr. Funnel. This foolishness went on for days as I wore out the fuel pumping, filtering, and sampling. The gascolator just refused to clear up.

Finally after serious some soul searching, I stopped the charade, removed thank, and opened it up by cutting off the circular access panel. What I found inside made me almost physically sick. The entire tank interior was absolutely covered with a fine grayish brown powder with a few larger particles. I spent a couple of hours scrubbing out the tank with hot soapy water and a rag. After drying the tank with a towel and airing it out in the hot sun for a few days, I re-installed it, plumbed everything up, and tentatively poured 5 gallons of fresh fuel from a better gas station using brand new plastic cans and a Mr. Funnel. More flushing and sampling cleared up any residual debris in the lines. Carb bowls and gascolator were also checked repeatedly and cleared up completely.

The takeaway from this harrowing experience:
1. Buy clean fuel from a source that sells a good volume.
2. Use only clean non-metallic fuel cans.
3. Run EVERYTHING through a Mr. Filter or equivalent.
4. Sample your Gascolator before EVERY flight.
 
Jack, As you no doubt know, it?s a pain. I broke down and bought a Flo-Fast pump. Works great. I have had some debris in my gascolator and the only possible sources were the pump and the electronic fuel pump which I recently replaced. I have convinced myself the electronic pump was the culprit. Should have flushed it out before installation.
 
This may seem a bit contrived, but I?ve tied a long string to the tab on the top edge of the Mr. Funnel. I place the funnel in the filler neck and then pull the string over the top of the fuselage and down to the trailing edge of the right-hand wing. Wrap the string around the control tube at the base of the flaperon, tie a simple taut-line hitch, and pull it snug. This Rube Goldberg approach holds the funnel in a secure, almost upright position to facilitate refueling.
 
Stuff in the tanks

Every 24 months I like to take out the wing quick drains out of my planes and let 1-2 gallons of fuel flow into a clean 5 gal bucket. This higher rate of flow can move contaminates that the little squirt into the fuel sample cup will not. I almost always get some grit or water droplets that never show up in the strainer or sample cup. Ymmv and all fuel handling precautions apply.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
I?ve been flying GA since 1985 and only encountered fuel contamination twice. Once coming out of the pump at an FBO and once when some lineman decided it was a good idea to fuel the plane in a torrential downpour on an overnight stay. I actually drew THREE sampler tubes of water out before I got fuel. It was so clear (pure water) that if AVGAS WASN?t blue I might have missed it.
 
The challenge for us RV-12 drivers is that, for the most part, we aren't running avgas. Many of us are running down to our favorite gas station and filling up 5-gallon cans at the pump. If you live out in a rural area, such as North Georgia in my case, you can't assume the gasoline is fresh and clean.
 
I use a use a Mr Funnel to filter the fuel from the gas station when I put it into a flo-fast container. The Flo-fast pump has another, pretty fine filter screen on it as well. Some of the particles look red, like rust.

Every since I started using the flo-fast tanks I've found red particles during the sump of my RV-12. Unless someone has a better idea I'm going to purchase a Mr. Funnel AF1CB Fuel Filter or maybe the larger one.
 
Mister Funnel

I started using the Flo-Fast system 7.5's and their best pump. I fill at Farmers Supply 92 no ethanol. I've found some red sediment during my sumps and so thinking about filtering when pumping into the plane. Should I buy the Mr Funnel AF1CB or the AF8CB to place in the aircraft filler when pumping? Or maybe something else.
 
FLO-FAST offers a 80 micron cartridge filter that mounts on the bottom of the pump pickup tube.

Question - How do you fill the 7.5 FLO-FAST container? Do not use the pump in reverse otherwise you will contaminate the clean side of the filter.

 
I?ve also seen grey powder in my carb bowls after the plane had sat for a while. I now make sure I fly at least every two weeks so I keep adding fresh fuel. Who knows what contaminants some of these auto gas stations introduce on rare occasions.
 
I?ve also seen grey powder in my carb bowls after the plane had sat for a while. I now make sure I fly at least every two weeks so I keep adding fresh fuel. Who knows what contaminants some of these auto gas stations introduce on rare occasions.

Just an observation regarding gas stations?

Most people use pumps toward center of fuel islands. You will notice that these pumps run slower because that are used more often causing filters to plug. Gas stations rarely change fuel pump filters.

Hot tip is to use pumps located further away. Pumps used less often, fuel flows faster, and filters are cleaner.
 
Here is the fuel transfer station I built for my Fokker biplane. My RV-12 hangar neighbor likes it so much he furnished a replacement battery for it.

It uses a Carter automotive fuel pump and an automotive filter. It pumps at ~1 gal/min and is powered by a retired PC-680. The aluminum nozzles grounds against the aircraft fuel tank. A 5-gal plastic can sits on the shelf and the ball valve prevents back flow when the can is removed. A power receptacle makes it easy to hook up a charger every ten can-loads or so.

fuel-transfer-web.jpg
 
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I really like the fuel transfer station you made. While I like the Flo-Fast, I think it is expensive. I think I could build one like yours for quite a bit less and have a usable cart.

My one question is about the 5 gallon can being grounded. Experts always say that the 5 gallon can should be on the ground when being filled at the gas station. Does the 5 gallon can need to be grounded when it is sitting on the plywood shelf on your cart?

I use plastic 5 gallon gas cans. I only put 4 gallons in each one because I am 72 and 5 gallons is easier to lift than 5. So a pumping solution would be good. I just wonder it the can needs to be grounded?

Thanks.
 
I use Terapump (3rd gen) from Amazon.com. Its so easy, takes 2 mins or so to pump out gas from can, while I can be busy untying etc. 4 AAA batteries lasts more than 50 pump cycles (not exactly counted but..)
 
It looks like your filter is before the pump, I put mine after the pump so if ever anything broke free from the pump the filter should catch it. I really love my pumping system. I have two 14 gal plastic cans with quick connects on the bottom along with shutoff valves. These cans are probably made for fueling up boats. I removed the fuel dispensing line that came with the cans and just screw in my suction line. Open the ball valve I installed on my suction line then open the valve on the can and pump fuel. When done, I lay the can down , close my suction valve. Wait a couple seconds and undo the connection. The little fuel in the connector flows back into the can and then close the valve on the can. Replace the dirt caps and I'm done. No mess and no hassle. love it.
 
Yes to the pump will fill the tank if the fuel can is on the ground,but the hose may need to be extended,I put my fuel can on a short 2 ft ladder and then insert the hose into the filler opening.
 
Will the TaraPump lift fuel from a jug on the ground to the filler port on the 12?

The way I do it and it works great for me is I get two 5 gallons red jerry cans filled from gas station using Mr. Funnel. Then just put one of them on the wing next to the fuel input port with the terapump directly in to the port input. It is kinda short, but works perfectly when I place it on the wing.

This works great for me and I wouldn't do it another way.
 
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