Monday, June 19, 2006
More on Ethanol Blended Gas
Here's a follow-up on the initial post, which you can find below this one.
Based on reports from boaters in Connecticut and New York, where ethanol-blended gasoline has been in use for over a year, the situation can indeed be problematic. For people with newer boats and engines, the problem is mostly confined to contamination and phase issues. In other words, when water is introduced into the blend, the ethanol gets out of phase with the gas and into phase with the water. (In phase means the two chemical constituents are combined into one system; out of phase means the two parts have separated into individual components.) Once the ethanol and gas have gone out of phase, the water and ethanol combine and settle to the bottom of the tank, leaving a reduced octane gasoline floating on top. In addition, because the ethanol is a solvent, it scours debris from the interior walls of the fuel tank, which causes contamination.
Some people (namely, Chuck Fort from Boat/US), are still suggesting people with older boats consider replacing their fiberglass and maybe even aluminum fuel tanks. I'm still not sure why this is an issue for older boats and not newer boats with the same type tank. I need more info -- like what material is it in the older fiberglass fuel tank that makes it more susceptible to ethanol corrosion. Are they talking about polyester versus vinylester resin? Epoxy resin? Is it the type of fiber we're talking about? The layup? What? Why don't they just say what the problem is? Clearly, it's not how old the tank is but what it's made out of that is at issue. They should just tell us what type of fuel tank construction materials are at risk and not talk to the boating public like they're a bunch of ignoramuses! (Another thing: It's just like the media and Boat/US to assume every person out there is riding around in a production boat, Bayliner, Starcraft, etc. Don't they realize how many boutique and custom boat builders there are?)
Meanwhile, as I mentioned before, these problems can be solved by keeping water out of your fuel tank, watching your filters and changing them more frequently, and making sure you use whatever gas you buy so it doesn't end up being stored in the tank for weeks at a time.
Unless of course, the place where you buy gas is selling contaminated and out of phase product. All your precautions won't amount to much if the gas you pump into your tank is contaminated with debris and already out of phase. You'll think you're getting 89 octane but what you're really getting is something with a lot less punch and a lot more dirt.
My recommendation is to find a place where the test of time has proven you can trust the gas. Stick with one place and don't shop around. You start to have engine problems, clogged filters, etc., flush the filter and fuel lines, replace elements, and find someplace else to get gas.
Another thing, the amount of water in the tank that they say is needed to cause problems is 1/2 of 1%. In a ten gallon tank (1280 fluid ounces) we're talking about 6.4 fluid ounces of water. A little less than a cup.
Posted by seabgb at 6:06 AM