long term gas test

[Dennis]

Guys,

Over the years, I have heard reports about using auto fuel and/or E fuel. In fact, as most know, according to the STC, we are not to use E contaminated fuels but I know some who do. And many of the reports were based on "someone else" experience. Things like aluminum corrodes, orings and rubber hoses are not compatible and will rot, fiberglass will dissolve in ethanol and auto fuel will separate. So, I decided to run my own little unscientific test. Each jar contains a aviation fuel oring, aviation fuel hose, aviation aluminum tube and a piece of fiberglass from a cherokee tip tank. One correction: the jar marked 100% Ethanol is actually 95%.

After one year, I will open the mason jars which are hermetically sealed and inspected by Funk and Wagner (just kidding on this part) and report my findings.

Dennis

[Paul Agaliotis]

Dennis,
The O rings and hoses can be manufactured from a variety of rubber and synthetic rubber compounds. Some are more robust than others in the presence of auto fuel and it's additives.
Generally the Mogas related problems are small ones. Quick drains that have performed for years start to leak, gascolators leak and embrittlement of hoses. I don't believe the engine will suffer any problems from using it,but the system needs to be compatible. Most of the old planes are not.
I have used Methanol as a fuel in the past and all of the hoses need to be teflon lined, any aluminum needs to be anodized. If left untreated the Methanol will react with the aluminum and produces a white oxide that looks alot like salt. I don't know it is I just noticed it's presence.
Paul

[SFC Hiatt]

Dennis

How about you put one in some good ole Arkansas moon shine. Just to have a neutral base.

Chris

[joea]

This could be a good test. Have often wondered how something like this would go.

And at the end, we can all test the moon-shine on the side!

[N86250]

Where are the jars with auto fuel alone or e fuel alone?? You might want to see what happens to them by theirselves. And I would suggest a mark for the level of the fuel on each jar in case it does evaporate through the seal. jrh

[Dennis]

Chris, It is in the frig. Saving it for you and Joe. I meant to take it to Oshkosh but I forgot.

Good idea from jrh. I will do it now.

Paul, I really wanted to check out the "Piper" fiberglass. I added the other items as an after thought and they were available in my shop. The aluminum is bare.

Dennis

[flyingfool]

I wonder about having too much things and not enough fuel.

What I mean is that chemical reactions "use up" the materials. In this case the Ethanol "IF" it reacts with one substance, there many not be enough of it to continue the reaction once the small amount of ethanol is used up. In a continuous use situation however, the fresh "new" ethanol is replenished over and over.

Similarly, with more than one substance for testing in each jar. If the ethanol wants to react with more than one, the 10% ethanol may be used up fast.

In either case, degradation may possibly be imperceptible. Where as if continuously replenished over time it may cause some problems.

however testing and data has to start somewhere.

One other test I'd be interested in is a sample with E10 and some water, and/or a sample with water in it. I'd be curious how the aluminum under water would do or in combo with alcohol.

[shorty]

A few months ago I purchased a new lawnmower from Tractor Supply.
It's placarded against the use of fuel containing more than 10% alc. An the warrenty will be void if >10% is used.
I think that a lot of the reason for the alc prohibition is due to two things.
#1- increased propensity for vaporlock, and
#2- the presence of water in the alc. leading to the corrosion of aluminum fuel lines.
While those are the main things, there are others
#3- Alc has shown to attack the sealants normally used in aircraft fuel tanks, A Cherokee will drip fuel worse than an SR-71 after the use of E-10 fuel.
I'm certian that there are other reasons not to use it, and the loss of power would be the least of them.

[Dennis]

Update:

The other day, I showed a fellow aviator what I was doing with the fuel samples. I have not looked at them since middle August. I was surprised to see that the cherokee paint had separated from the fiberglass in the mogas/10%E jar and to a much greater degree in the 95%E jar. I swear, it looks like tape worms.

I got the strips of cherokee fuel tank fiberglass from a local savage yard. The paint look very old and appeared that it may be the original enamel color.

So, the first conclusion I have drawn is after doing some painting, drink some pure grain alcohol to break the paint loose in your windpipe.

BTW, there were some very good suggestions. I did mark the liquid level as suggested. After one year, I may change the parameters for a second round. Anyway, it is certainly not up to scientific lab levels but we might just get a little useful info.

Dennis