Fuel handling and storage?

[Bill Adair]

I'm always interested in how folks handle and store their fuel, and particularly when it goes bad sooner than expected. I see many people who draw their fuel from jugs with syringes, and never bother to cap the containers between flights.

That's one of the reasons I like electric fuel pumps with closed fuel systems. The only exposure to air is when the supply line is pulled from the can or bottle female vent fitting, to be connected to the tank fill line. The only exposure to outside air is via the open end of the pump supply line, and the very small diameter vent receptacle in the container cap. The supply line is then plugged back into the fuel cap vent receptacle when finished fueling.

I'm also concerned that plastic jugs are not as air tight as metal cans, and some of my fuel has been stored in unopened gallon plastic jugs for many years. That stored fuel might have already absorbed some moisture through the plastic jugs.

I've always emptied these jugs into my fuel pump equipped metal can, being careful to minimize exposure to air during decanting.

So how do you handle and store your fuel?

Bill

[Paul Taylor]

I keep mine in the garage in a milk crate. Keep them off the concrete floor. I am sure as hot as it is here in the south it is not the best place. I try my best not to keep it long. I did have a qt of Fox fuel for our Norvell's that we had not used for a year. It ran out engines fine last week.

Paul 

[Bill Adair]

Paul,

Thanks for your input.

My fuel (Red Max) is still in the cardboard cases that it came in, but has been in one garage or another for nearly ten years now. Figure I can use it for break-in, and washing dirt clogged engines if nothing else.

Yes, I was always pretty good at planting airplanes, with the engines running! 

Bill

[Jim Thomerson]

I'm presently flying 3-year old fuel.  I leave it in the carton in the shop. I fuel with syringe and try to remember to put the cap back on.  When I get down to a quart or so in a jug, I open another jug.  When it gets down a bit, I pour the old quart in. I think fuel absorbing water from air is a myth.  I think keeping it capped and out of the sun couldn't hurt.   

[Brett Buck]

So how do you handle and store your fuel?

   I get my fuel in metal cans (Powermaster) and use the DuBro plastic fuel can fitting gadget:

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRS88

    It's not a lot different in principle from the old brass fittings, but the plastic and aluminum don't corrode, and the aluminum bayonet fitting is sealed with an O-ring and does not allow the fuel to "breathe". Leave it in a hot car, and it will inflate but not leak air, close it when it's hot and the sides of the can suck in. Good as capping it off. Of course, the flow is one way so put a filter in the takeup line and that will take care of it.

    Other than sealing it off, I don't take any care at all to be careful about storage conditions. I leave whatever fuel I am using plus a few extra cans in the back of my van in a box, and don't worry about temperature swings. As long as nothing goes in or out, the fuel won't degenerate from merely being heat-cycled over any normal temperature range. Good thing, too, since my house is not air-conditioned and can go from over 110 degrees in the day to low 50s in the same day.

   As long as it's sealed up and isn't allowed to form condensation, and you keep it in an opaque container, fuel will last almost indefinitely. The fuel I ran at the NATs this years was a mixture of various partial cans of fuel I had used in 2004-2007, no issues as anyone who heard/saw the engine run can attest. I run 15% only at the NATs and TT, and the NATs usually takes about a gallon + about two tanks full, so I end up with opened but almost full cans that I only use once a year. I usually consolidate the partial cans right before I leave so I only have to carry full gallons.

      I use a 5-ounce veterinary syringe with a Carl Shoup replacement stopper and the red (silicone) o-ring. Jim Lee makes a very good syringe stopper as well. The stock black stopper will wear out in about a year or so, and I am dubious about what it might be putting into the fuel. Since I started using the red o-ring stopper, I haven't had *any* hint of a plug "tater", black crud, or frosting. Maybe that is related to the stopper, or not.

    I like the veterinary syringes over the Jett fueler even though I need a lot more than 5 oz of fuel. The Jett fueler is plenty big enough, but I like having a place to put a screw to hold the free end of the fueling tube. I actually have two screws on the flange of my vet syringe - one for the free end of the fueling tube, and another that carrys a short length of silicone I attach to the overflow to keep it off the side of the fuselage. 

     At least with Powermaster fuel, there is absolutely no value to filtering it externally and a whole lot of reasons to NOT attempt to filter it by decanting. There is *nothing* to filter, period. I also found absolutely nothing to filter from SIG fuel when I was using it. The up line of my fuel can pickup has a screen on the pickup end (comes with the DuBro kit) and I am using a Dirty Dan "Russkie" filter (screw-apart with a fine screen and never once have I found ANYTHING in either one of them, nor have I found anything in the airplane filter after the first few runs on a tank.

     I used to run the Dave Brown six-shooter pump that works by peristaltic action, and that's pretty good too.

     I know my stunt heros Paul Walker and Howard Rush (and about everybody else in the NW) use the condiment/ketchup pump. Maybe they have different pumps that everybody around here has tried, but I have seen several locals have nothing but severe contamination problems using them. I think they shed something during use. Note that Howard and Paul also use huge car fuel filters on the output because the small filters clog too quickly. Given that I have run literally a hundred gallons of the very same fuel through airplane filters and never had even a little bit of crud, I am forced to conclude that the particles they find are self-generated by the pump.

    Similarly, I know of locals who routinely filter the fuel by decanting from one container to the other through some sort of filter medium, usually a coffee filter. That, too, seems unnecessary with either SIG or Powermaster, since there's nothing in the fuel to filter out, and the coffee filters tend to shed fibers into the fuel. Fibers are very bad, since they can make the engine run very funny but not actually make it quit. In particular, I have seen cases where a fiber got wrapped around the needle with the free end trailing out the spraybar, out the spigot, and flop around. This had the effect of sometimes defeating the atomization of the fuel, instead allowing to to stream down the fiber and just dribble into the engine. It ran VERY strangely since it only did that sometimes and at some input air angles. That's when we learned to always wipe the needle with our fingers instead of just flushing out the spraybar when you have problems.

   I also use the Sullivan fuel system cleaning kit. It comes with two teeny-weeny bottle brushes that will go through the spraybar and physically remove anything like a fiber.


      Brett

[Noel Corney]

I have always made up my own @ i agree with Brett, old fuel like most alcohol seems to get better with age. Also I asked the from the chemical company I get my ingredients from @ told me most plastic is o/k just keep it off the floor , especially concrete. Regards Noel.

[Garf]

I only know one thing beyond a shadow of a doubt. NEVER store fuel in a plastic soda bottle. Tried that once. Expensive lesson.

[Bill Adair]

Thanks for the replies, everyone. 

Brett,

Great description of your fuel handling methods, and your reasoning behind them!

I couldn't agree more about clean fuel from the major fuel suppliers. The last thing they want is to sell contaminated fuel, and I'm sure their final filtering and handling methods are far superior to ours.

After seeing the amount of dirt and crud that accumulates in an R/C engine muffler after a few months of flying, I decided to use a filter in the muffler pressure line. I don't think those fine grains of grit, and carbon would be good things to have in our tanks.

Uniflo or standard C/L tank plumbing probably doesn't collect near as much contamination through those tiny vent tube inputs, but using muffler pressure is another story. The amount of crud sucked through the venturi, and blown out the exhaust, and likely the pressure line might surprise some people.

Bill

[Brett Buck]

Uniflo or standard C/L tank plumbing probably doesn't collect near as much contamination through those tiny vent tube inputs, but using muffler pressure is another story.

   It's a minor problem with a muffler but with a pipe it's a real mess. When I run pipe pressure, I put a filter in the pressure line between the tap and the tank.

   One thing I forgot above - if you use carbon fiber tanks you *will* get some self-generated particles after a while. In any case, metal or graphite, I use a filter in the airplane - either the teeny little aluminum ones you get from R/C pylon sources, or the Sullivan Crap Trap.

  Brett

   

[Kreth]

My first thought about water getting in through the plastic was - I don't think so.  I emailed my chemist, laboratory president, technical director son and got this response.

OK, A question for an expert.  There is a discussion about storing fuel on a model airplane forum.  Can moisture get into fuel through a plastic jug over time.  Forget that the cap seal exists or that opening it to atmosphere introduces a small amount.  I know that methanol is hygroscopic, but could a water molecule pass through a plastic jug? 

My guess is No Way.

Dad

"Permeability of the plastic, if it exists, would also be true of the fuel.  The fuel would evaporate 1000 times faster through the plastic before any water ever even thought about sneaking into the container.

No, water will not permeate plastic, no matter what grade."

  

[Brett Buck]

"Permeability of the plastic, if it exists, would also be true of the fuel.  The fuel would evaporate 1000 times faster through the plastic before any water ever even thought about sneaking into the container.

No, water will not permeate plastic, no matter what grade."

    Thats not too surprising to me. My issue with plastic is that it is easy to get a crack or cut in, so it leaks. Just flexing from heat changes can crack it, and leave you with a trunk full of fuel. Additionally, it's not opaque and light will definitely alter the fuel.

  That being said, as long as you store it correctly, and only take the fuel you are currently using, all of these things happen so slowly that it really won't be an issue.

     Brett

[Kreth]

I totally agree.  Concrete floors are also like permanent sandpaper or a flattened out grinding wheel - and jugs are often so thin it doesn't take a whole lot of sliding around on it to develop a leak.

[Garf]

I only know one thing beyond a shadow of a doubt. NEVER store fuel in a plastic soda bottle. Tried that once. Expensive lesson.

I tried storing fuel in soda bottles. After a few months, the fuel seperated. If I were to shake the bottle, the resulting mix was milkey. This mix rapidly seperated. Once seperated, there was no sign of milkiness.

[Charlie Pate]

I have always made up my own @ i agree with Brett, old fuel like most alcohol seems to get better with age. Also I asked the from the chemical company I get my ingredients from @ told me most plastic is o/k just keep it off the floor , especially concrete. Regards Noel.

A fellow I once  knew,flew Team Race .He swore up an down he got more laps from the same amount of fuel
if he left the fuel jug in the back of his station wagon bouncing around for a week as he drove the vehicle.
 I can,t say ,yea or ney to his prognostications on this; i did find it  an interesting theory   

[Ed Keller]

Brett - I take it from your info that PW & others are not having any trouble with the condiment type dispensers. I have been using these for several years & no trouble so far. I am wondering if there are several mfgrs of these. I saw a lot of them in Muncie.

[Brett Buck]

Brett - I take it from your info that PW & others are not having any trouble with the condiment type dispensers. I have been using these for several years & no trouble so far. I am wondering if there are several mfgrs of these. I saw a lot of them in Muncie.

   As long as it has a giant automotive fuel filter, no, not much is getting through that.

     Brett