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100ll shelf life

Lan Vinh Do

Well Known Member
Hi
I try to start a flight club in my area and maby buy a fuel tank.
The company that would see me the 100ll say that it have a shelf life of 3 month and the minimum to be old is 5000 gal at a time. When i read on he internet, a lot of place say that the shelf life is 1 year. It would be a co-op non profit and there would be a big difference if we have to use 5000 gal a year vs 20 000 gal. Year
Anybody have more info??

Thank you

Lan vinh Do
Rv10 c-gmce
 
A few months back I saw an excellent webinar by Swift Fuels (of West Lafayette, IN) that showed photos of the degradation of 100LL with time. The amount of precipitate-like material in 100LL after a month or so was shocking. From what I saw, I would say the 3 month estimate is much closer to accurate than the 1 yr estimate.
 
How long?

I've seen several planes flown on 100LL that was a year or two old with no issues. I've been under the impression that 100LL didn't spoil. Auto gas is another story. I think I'll put some 100LL in a jar and let it sit. If it goes bad in a month I will be shocked.
 
I've always heard a year with the additives they put in 100LL. Mercruiser maintenance school taught auto-gas has 21 day shelf life hence the need for stabilizer.
 
I've seen cars sit for 8 months with auto-gas in the tank. No stabilizer or anything. They started and ran terrible for 10 minutes or so until the gum got flushed out of the system.

If I remember properly, the expirey date stamped on sealed Avgas fuel drums is 2 years.
 
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me too!

Lan vinh,
our local club is also in a similar boat, and wondering if all the hassle is worth getting a tank, probably additional liability insurance, or starting up an LLC separate from the club to cover the fuel 'business' while remaining, as you say, a non-profit or co-op style operation.
Would appreciate if you stay in touch by PM or whatever.....how you will sell it, by card-lock etc., and if you will sell to transient aircraft ( which would increase your use, likely getting you to the magic 20,000 litre mark if desired).
Heck, we're not even sure if anyone local will sell to us, or deliver it?
I read somewhere that shell, Imperial, and Petro-can are the only avgas refiners in Canada, but maybe you have some options out there on the east coast.
good luck!
P.S. are Ace McCool and DEI still flying out of Moncton....at 50 and and 1/8th? :)
 
Last year my son bought a 1966 Bellanca Cruisemaster that had sat in a hangar for 15 years. One tank had dripped out onto the floor and was empty.
the other two tanks were full of 100LL, which was clean blue and smelled perfect.
We dutifully drained it and put in new fuel for the first flight to go with the rebuilt engine, but that old fuel still was clean, without any sediment or other visible defect, and it sure did explode when we used it on a brushpile.
!!:D
 
Some years back AOPA (or was it the EAA) had an article on the differences between auto fuel and 100LL.

One of the things they mentioned in there was that auto fuel was good for one year and 100LL was good for two.

Take this all with a grain of salt (OK, maybe a salt lick) because try as I might, I have been unable to locate this article on the net.

Maybe someone else remembers that article. BTW, that could got back more than 20 years.
 
Just flew a C 140 today that had not flown for 11/2 yrs. Checked the fuel and it was nice clear/blue and smelled good. Flew it with no issues. Don
 
Article was written by a Shell Engineer.

I would expect the oil companies to be conservative and put on a date. Cost them nothing to publish a date and they get to have people throw away un-used gas and buy new gas. Also helps with the lawsuits as they can claim old gas past their recommended usage date if there is ever an issue.

Would like to see analysis from a lab.
 
Last a long time

I posted this once but it was deleted for some reason. I have stored 100LL for over 2 years and did not notice any difference when I did use it. YMMV.
 
The true being known, 100LL IMHO will cause ill effect after a year of storage. Will it work and still burn, yes... but it does cause some havac. :)
 
I collected the daily sumped fuel out of the gas truck for a car I had for a couple of years in a 5 gallon can with out any trouble. One weekend I went to get my can and the fuel was spoiled. It has turned a tan color and has lost its smell. It was about 3 months old. The car that has that fuel in it will not run now. I have a suspision it is the fuel. It isn't gummed up, just discolored and doen't smell right. I think it might be the blend or the temperature that does it. I have also run airplanes that have sat for several years and the avgas has been OK.
 
100LL

The true being known, 100LL IMHO will cause ill effect after a year of storage. Will it work and still burn, yes... but it does cause some havac. :)

Such as? Did you have a bad experience with some old 100LL? I have a terrible time using auto fuel with alcohol in my small engines. It seems to tarnish and plug up the low speed jet after about 3 months. I've never had a problem with 100LL, even after extended periods. Just curious.
 
Such as? Did you have a bad experience with some old 100LL? I have a terrible time using auto fuel with alcohol in my small engines. It seems to tarnish and plug up the low speed jet after about 3 months. I've never had a problem with 100LL, even after extended periods. Just curious.

Yes, a few times... had a 210 sitting with fresh fuel for 9-10 months, backfired and carried on until we added 30 gallons of new fuel. Made a heck of a difference.
 
Saw a Cherokee 140 fly last year that had fuel from the late 90s. The tank was down less than a gallon, mechanic couldn't find anything wrong with it, and it ran great. So it seems like ten years is a better estimate. Fuel companies would rather you bought new stuff every few months, however. Auto gas absolutely will not keep anywhere near that long. I have heard a wild rumor that some people keep 100LL in their back-up generators and such.

Bob
 
Life of 100LL

There was an episode of Ice Pilots this year where they were putting a DC4 back in service that had sat for three years I think. After doing all the maintenance, they couldn't get it to start. They drained the fuel and pored some on the tarmac (cement) and tried to light it, and it would not light off. Put fresh fuel in the tanks and the AC started. I do know that some avgas in fuel dumps in the north is a number of years old however, and is used w/o problem.

My own experience is, that the field where my 4 is kept is not useable in the winter, I fill the tanks with 100LL, usually in November and usually don't fly again until April. Never had a problem.

Joe
 
as long as your tank is sealed and there are no leaks in the system you should be okay. once you have a leak the hydrocarbons inside will leak out. if you have ever opened a drum of fuel and the rush of gas coming out, you will know what im talking about.

the bigger problem is usually your states Dept of Weight & Measures (or whoever handles this task) will want to verify your pumps output every so often (usually once a year). and some if not all states want a permit for every pump.
 
Thank you

Thank you everybody for all your help. It is really usefull.
I will see if we are enough to burn 30 to 40 000 litre per year and if yes, i will buy a tank. Like this the tank will be refill each 6 month. Like this we can pay 45 to 55 cent less each litre here ( they make 2 $ of profit each gal here )
 
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