Old fuel/mixing fuel?

Contrary to what you may read from certain individuals, no matter what brands you have, you will not likely encounter problems because all glow fuel is just oil and nitro mixed in methanol, and possibly an anti-foaming agent.

My method: I have a plastic fuel jug with holes drilled in it to accomodate fuel tubing that goes to the hand crank pump. Whenever the level of fuel in this field jug gets down to around 1/4 or so, I pick up whatever fuel is handy and fill it to the top. Currently I have about 4 or 5 brands mixed in there, and I never have any problem at all.

My RC habit is driven by wheeling and dealing. I have bought out several individuals over the years who have become too old to pursue the hobby. I usually end up with their old fuel, some of which dates back to the 1980s. Currently I have about 15 gallons in my basement, comprised of about 6 or 7 different brands or formulations. I have never had a problem resulting from mixing fuel, using "old fuel", or using the "wrong fuel" in any sport engine. If you have a specialized engine such as a pylon racing engine or other finicky piece of equipment, all bets are off. But if you are using basic equipment intended for Sunday flying, mix away! I would be willing to bet money that you will have no problems at all, as long as you don't have a jug of fuel that has gone bad.

I would avoid mixing brands because you never know what compatibility issues may arise. Most fuels use very similar products, but some may have additives that are not compatible with additives in other blends.

Considering that Robbie Reynolds and I have never had any mutual admiration society, this could be somewhat surprising. I totally concur with his response regarding fuel. I think he covered all the basis.

Fuel with those little white specks, indicating bad castor oil could be bad, old or new. Every once in a while some local fuel-dude decides to replace the nitro-methane with nitro-ethane. Not good. Then there is that local type that tries to use nitro by weight and not volume. That makes for some "HOT" fuel.

I've mixed many kinds, old, and different brands and as Robbie says, it's fine for the Sunday crowd.

OTOH, since some 5-6 years ago I came by some Wildcat fuel, Since then that has been my choice of choices. Still I use the older even if several years old, as I get it when I journey north each summer or have a 40+ gallon supply

18-wheeled to the house. Still mix up various nitro/oil blends for sport flying. Burned some today and will again tomorrow.

Robbie,

I've only gone with 2 so far, and mine ran fine. One was a pink color, the other green (Coopers Custom Blend & Cool Power). Only thing is those colors make for a pukie gray glow fuel jug. --

Jim L.

Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1

CainHD,

My thoughts on mixing old with new is any possibility of loss of octane/fuel volatility should be negated by mixing old & new.

When I used to race cars at the drag strip, we'd mix regular & premium, which got us up a couple points in octane. When unleaded fuel became dominate, that trick came in handy. Ahhh, the days of Sunnoco 260 &

12:1 compression big blocks! --

Jim L.

Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1

That's half the fun of mixing fuel! I always enjoy seeing what color it's going to be. Then you can take bets on what color slime is going to end up on your airplane.

Those 'little white specks' are precipitates left over from "chemical pressing" of castor beans.

If you ever figure out which brand of fuel they came from, stop using the stuff 'cuz the castor is second (or third) rate.

Good castor is virgin first pressing (mechanically extracted).

Chemical pressings are 2nd and 3rd pressings, done to extract the last little bit of oil from the beans. Cheers, Fred McClellan The House Of Balsa Dust

Ricin?? :(

Those little white specks can also show up if your fuel gets very cold (freezing or below). If you shake the fuel and the specks disappear and do not reappear later, the fuel is OK to use. This is from the maker of Excalibur fuels.

This is interesting information. What exactly did they put in the fuel?

Perhaps you should read what FHS/RedMax has to say about the quality of current castor oils :

Cheers, Fred McClellan The House Of Balsa Dust

Fred,

Great article! --

Jim L.

Using - Virtual Access(OLR), ZAP 4.5, & WinXP Pro w/SP1

You should also look at the dates of those reports. That was 6-8 years ago. Plus the fact that castor blended fuels have been used consistently all during that time period with no major reported problems, especially in Europe, where "straight" fuel (20% castor, 80% methonol) was far more popular than fuel with nitro and synthetic oils.

I am not saying that there wasn't any bad castor around, just that it has been used successfully by thousands of fliers without the doomsday predictions.

AS a side note, I have used FHS oil for several gallons of racing fuel and can vouch for the quality.

Quality? From someone who says this in point 7: "The outside of the engine was, of course, badly rusted." You chaps in England got some iron block engines? :-)

Where did you get the idea that it was in England? And where did you get the idea that the quote is from the company? Read it again.

There was a thread some time ago in SSW concerning the claims by Redmax. One of the posters was a chemist who analysed their fuel containing castor and found trace amounts of xylene which is used in the chemical processing of castor and is used by "third world" countries, not by the larger manufacturers such as Castrol. The Redmax statement that any castor fuel mixed at 20% will go bad in "anywhere from a few hours to about two weeks" is laughable. I've used Castrol M for the last 45 or so years mixed at 20%+ and have never had any go bad even when it's years old.

Brian Hampt> >