n our area (around Norfolk, VA), the EPA just mandated gasohol (90/10); we just can't buy just plain old gasoline anymore. I had a very hard time finding enough fuel of any type just to get home from the big Virginia Beach Boardwalk show last Saturday.

We also tend get lots of water in fuel down here; sometimes salty water. Corrosion has long been a big problem; one really bad batch turned green after eating the copper out of my sender and seriously attacked steel, brass, and aluminum parts (the plastic parts were OK) throughout the fuel system. [The Holley carb's metal held up much better than the Carter carb's metal; maybe due to the former's olive-drab coating?]

Typically, I drive my classics only <500 mi/year, and a tank of gas lasts a long time. I add Mystery Oil at last last fill of the season, and sometimes Fresh Start if the they seem balky at the beginning of the season. I tried a couple of the fuel preservatives w/o much success and gave up on them.

I've read of using antifreeze to test for water, but I'm unsure whether that test works with so much ethanol present. Is there a do-it-yourself way or kit to detect disolved salt water, methanol, or other contaminants?

About 17 years ago I ran 90/10 gasohol exclusively in my cars in Indiana w/o any problems and was very happy with it, but I never had the contamination problems there that I see down here.

I know I could drain my classics dry after every drive and use that fuel in my daily drivers, but that is a real hassle and I'd really appreciate a better solution.

Only real solution I can think of if your fuel is that badly contaminated is to install a fuel water separator of the type intended for diesel-powered vehicles.

The Carter carbs were originally corrosion-protected with a coating such as that you describe on your Holley -- perhaps the Carter you're working with was a "remanufactured" unit that had its protective coating stripped off and not reapplied, which is common.

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Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan. If I was dealing with just gasoline and water, a water separator in the fuel would certainly help protect the carb, but it couldn't do much to protect the tank, sender, pump, and lines, especially when the fuel sits in there for months. The gasohol will go a long way to keeping the water and contamination in solution much more than just gasoline would.

A sample of the really bad fuel didn't show any noticable separation into layers when left in a glass jar for few days - even though it was quite green, presumably due to the copper it ate out of the sender and the brass float. It then put holes in the tank, and when I drained it into an external steel gas can, it ate holes in it too.

That really bad fuel wasn't labeled as containing any ethanol or anything else special that I can remember. I don't want it to happen again and I fear that all the gasohol here will have lots of water in solution. I anticipate this will be a much bigger problem for rarely driven cars than for daily drivers.

I'm now thinking of circulating the fuel out of the tank via an electric pump through some sort of homebrew filtration system and back again and letting that run for awhile after every fill. Perhaps there is something akin to a sacrificial anode I could use?

Probably I first need to figure out what the contamination is; since I only see problems sometimes, I'll probably need to test every batch.
Is there a kit to do that that a mere hobbyist can afford?

I'm hoping the gasohol will be held to better standards than the gas has been, but I'd rather not count on it. I have found products on the web that claim to prevent fuel system corrosion - any comments on them?

Briggs & Stratton used to sell a nice little alcohol-in-fuel test kit for about $10. Consists of a calibrated test tube with a screw cap. You add gasoline to the "gasoline" line, water to the "water" line, cap it, shake it and let it sit upright for 10 minutes. The water/fuel separation line shows the percentage of alcohol in the fuel. This also suggests a means by which alcohol could be precipitated out of purchased fuel, but it'd be messy and hazardous...

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Too many people who were born on third base actually believe they've hit a triple.

Thanks for the Briggs&Straton lead - I'll see what I can find with them.

In reading an old 1950s reference last night, I saw that acetone was commonly used in keeping the alcohol in suspension, while some people used a lot of benezene in their fuel.

I would suspect that adding benzene would tend to force water out of the fuel, while acetone would tend to hold the water in. Perhaps phenol (C6H5OH) would be a good choice and less likely to attack anything. I've already replaced my 3R507 fuel line with 3R509 after reading about the fires near DC.

I wonder what would happen if I used a rather reactive metal (say magnesium or calcium) to react with any corrosive contaminates to form inorganic salts that I could then precipitate out; perhaps using electrostatics? Or better, salts that don't dissolve in the fuel at all.

I have tried putting dry ice into the tank to expel all the humid air before leaving it for months, but then decided that was too little too late; the fuel is probably water saturated by that point.

I have to research into this some more before I give it a shot.

FYI: I've done some research, and it looks like the main thing with gasohol is to keep it very dry; not always easy around here. Most sources report that anything over 0.3-5% water is serious problem, as the alcohol/water mix will seperate out, sink to the bottom of the tank, stop your engine.

The Briggs&Stratton catalog says their kit just measures the amount of alcohol present - I will try to get a $6 kit, but it probably can't tell me much other than that.

I plan to begin by measuring the temperature at which the water/ethonol seperates out from the gasoline out; it should give me a good idea of how much water is there. That is not a good way to remove the water, as it removes other things (including ethanol) too.

Apparently, mixing gas containing MTBE with gasohol can lead to seperation too, which is why the local gas stations ran their tanks dry last weekend.

After I cool a sample and look for seperation, I'll then try using benezene to also force a seperation.

It looks like there are some compounds that at the 5-10ppm level will help protect against the corrosion I've experienced, but I've yet to find a source of them suitable for a hobbyist.

I'll see how it goes.

Well, the gasohol samples taken directly from the pump showed no seperation, but my daily driver started having problems and so I took a sample from it.

The sample looked somewhat cloudy; placing it in the freezer produced 2 distinct layers. We've had a really wet month and I suspect that the water just came from the air that replaced the gas as I drove.

Does anyone have a good way to get the apparently mostly alchohol/water and gasoline parts to mix again, other than heating? Maybe acetone + another batch of fresh gasohol? Dry gas is alcohol, although it is either methanol or isoproply and I suspect it won't help much.

[PS The B&S test kit turned out not to be very suitable for gasohol.]

For lack of a better idea, I mixed in 24 oz of isopropyl and 14 oz of acetone, then added 7 gal more gasohol to the 7 gal of cruddy stuff that was in there - at least it's driveable again. I will try to mix it better tonight w/ compressed air pushed backward through the fuel line.

I also noted that there are signs that my 3R507 fuel line (that is a few years old) seems to be shedding small black debris.