more ethanol woes

[896tr]

I've been helping a friend get an ultra lite ready to fly and found out the hard way how fast ethanol eats older fiberglass fuel tanks. Late last Thursday night we got the engine started (one pull on the rope! Rotax really is a nice engine!). It was late so we let it come up to temperature and shut it down and called it a night. Friday evening we decided to taxi it around to see how it felt. It tried to start a few times but would not. Two hours of tugging on that stinkin' rope and it was time to quit for the night. Saturday had the same results, we even tried four sets of new plugs. That's when I noticed little black particles in the fuel filter. Crap! Older fiberglass tanks and 91 octane car gas. Over night the ethanol had done it's job. I would not have believed it had I not experienced it first hand. There was goo in everything, The fuel filter, the carb.,the pistons, everything! I had planned to slosh the tanks on my series 6 but not now, av gas only. My wings are already done so all it would take in my mind is one little spot not to get sealed and I wouldn't be flying for a while.

My question is, has anyone had first hand experience, or really heard of anyone having a problem with av gas and fiberglass thanks? If I have to I will get the new tanks from the Mcbeans but I will never use car gas in my plane after this experience.

Steve

[DesertFox4]

Had the same result the one time I tried to use alcohol "enriched" auto fuel in my model 4 tanks. My tanks are most likely early to mid 1990's vintage. I too must use Av-gas. Absolutely no issues running Av-gas in my fuel system.

[GWright6970]

Excellent question.... I am right there with you. Old style fiberglass tanks, already installed, and NOT coated inside. The wings are NOT covered.

If we do flush them out with 100LL and stay the course, at some point we will be right with remainder of the general aviation community, and have to deal with what ever comes out of the ceasing to manufacture 100LL.

Or, we bite the bullet now, pull them out, and replace them now.... another $1,000 + (I have the two 13 gal's) added to the cost. But we do get to use auto gas....

Yesterday I put 100LL into one of our club planes, at a price of $5.03/gal. Auto gas out on the road was $3.89/gal.... a difference of $1.14/gal. (It is going to all go higher now that we just had a Chevron Refinery fire in the SF Bay Area.)

But at say, this $1.14/gal savings, that is using 877 gallons of auto fuel to recoup that cost savings.... If we burn 4gal/hr, then that is 219 hours of flying, and in X hrs/year flying.... OK, I'll admit that am trying to use the math to convince myself to pull the existing tanks out and replace them.... I just wish that I could assure myself that I could get an army of my friends together and have a "wing fuel tank coating party," and have it REALLY coat the inside surfaces COMPLETELY!

So I wish to add my nagging question, (which I used the site search engine to find but came up with nothing) :

Has anyone ever successfully REMOVED previously installed 13 gallon fiberglass tanks, coated them successfully inside, and then re-installed them without any leaks, etc??

[tommg13780]

During the previous 2 years I was "washing" the ethanol out of my pump gas. I realize that this is not a generally recognized solution to the problem and I'm not interested in debating the benefits and/or hazards with those who wish to argue on either side of the issue.
If there are people with older fiberglass tanks that want to hear more about the washing process I can explain my methods and proceedures which are quite simple, effective but perhaps a little more messing around than most people want to get involved with. In my case it was not so much a case of fuel cost savings but I like to travel by trailering and have my fuel supply on board (the trailer) and it was a matter of swapping one inconvienience (washing) for the reliable fuel supply. One more detail is that my power is provided by a 582 Rotax.

[Av8r_Sed]

I've got the 1990 vintage fiberglass tanks which have been in service since March this year. I've been ferrying fuel from Southern WI (50 mi round trip) to get Ethanol free 93 Octane auto gas which I test each time. So far I have no issues with fibers, brown crap or leaks from the tanks.

My wings had been closed up for years so I decided to go with what I've got to get flying and I'm happy with the decision so far.

Disclaimers aside, I would be interested in tommg's process for washing the Ethanol out of the gas. This would be no different than the common "Olive Jar" Ethanol test. I'm just interested in how to make sure all the Ethanol is gone and the best way to separate the water/ethanol from the washed gas.

[dholly]

@Tom- we have E-Free Premium auto gas available at a handful of filling stations in the upstate area now, also E-Free Regular auto gas at many marinas. Nothing down your way?

[tommg13780]

Paul,
my approach to this is as follows:
1. dump a quantity of ethenol pump gas into a poly, metal or whatever container. Let's use 5 gal.
2. Add 2 quarts or so water. Shake, or if you prefer stir. 10% e-fuel should have about 2 quarts ethanol content per 5 gal.
3. Dump the combined fuel/water fluid into some type transparent container. The dumping action gives an additional shake/stir to the fluid. I'm using an old style glass water cooler jug approx. 6 gal. 10% e-fuel should have about 2 quarts ethanol content per 5 gal.
4. In less than a minute the water/ethanol goes to the bottom and the remaining ethanol/water free gas is on top just like the little testing tube. The so called phase line is clear as day and night, just like in the test tube.
5. Now it's just a matter of pumping or siphoning the top product or if you prefer, and you are a little more innovative, have a sump and drain the bottom fluid.
6. At this point I put the remaining ethanol free gas through a MR. Funnel as it siphons to another container.
7. If you really want to capture every drop (almost) after the siphon process dump the small amount of mixed fluid into a glass measuring cup and suck up the good stuff with a turkey baster. (optional)

Notes: The higher octane e-fuels tend to run a lower percentage of ethanol, on average around 5%. My recipe still works fine, just produces a little less waste. Actually I beleive that the water added will cling to a volume of ethanol greater that itself. Realize that you have degraded the octane value of the remaining gas. My solution to that is blend in some 100LL and the color becomes much more attractive also.
I do realize that this is a rather simple minded approach to a problem that may be to complicated for me to fully understand. But my testimony is based on about 100 hours of flying thgis stuff without any perceived problems. All that brown slime that would show in the fuel collator cleared up almost completely with only traces showing.

[tommg13780]

Doug,
I saw that up around Fulton and Oswego NY when traveling to the Gullivers flyin. Looks like the Fastrac Stations have substuted the ethanol free instead of Mid-grade. Some of the locals up there are using that fuel and finding that it lowers EGT's by enough that re-jetting is nessary on rotax 2 strokes. Actually I don't necessarily need it now because I'm using different wings with alum tanks, so far trouble free.

[rwaltman]

... E-Free ... Nothing down your way?

There is a list here:
http://pure-gas.org/

and a map here:
http://pure-gas.org/extensions/map.html

Zero in New Jersey, some in New York but nothing nearby.

One more:
http://www.historicvehicle.org/Resou...s/Pure-Gas-Map

Roberto.

[Av8r_Sed]

Thanks Tom. I hadn't considered the effect on Octane rating I'll keep the process in mind if the Ethanol lobby advances any further in my area. Otherwise I guess I'll enjoy the rustic drive to the e-free gas station.