E10 may cause problems in older boats

Should boaters be concerned about using today's gasoline that contains 10 percent ethanol, commonly known as "E10"?

One of Water Ways' three regular readers, Ray Sweeney, remembered a column I wrote about a year ago regarding the reported ill effects E10 had on some older boats and asked for my thoughts on a bill now being heard in the Legislature.

The legislation -- House Bill 791 -- states that ethanol is damaging to the non-metal parts of the fuel storage and systems of marine engines and other small gasoline-powered tools.

To circumvent such damage, the bill would require refiners to make gasoline without ethanol available to marine fueling stations and their company-owned and operated stations.

In my earlier column about ethanol, I referenced tests done in both Australia and the U.S. that indicated that while boats built and powered since the early 1990s have had few problems using E10, older vessels have experienced difficulties.

There have been several articles in national boating publications since those tests were done that have shed more light on the problem and have offered suggestions to owners of older boats on how to cope with the E10 blend.

To begin with, it should be recognized that ethanol is essentially grain alcohol, like vodka. It is added to gasoline as a safe replacement for MTBE (methyl tertiary-butyl ether) -- a known carcinogen -- that had been used to replace lead.

Ethanol is an oxygen-enriched octane booster that's required by today's high-compression engines. However, unlike its predecessors, ethanol is a solvent that can weaken older rubber fuel lines and gaskets, dissolve the varnish and sludge found in many fuel tanks, and even begin to dissolve the fuel tanks if they are made of polyester resin fiberglass.

Once these dissolved materials in the fuel reach a boat's engine they tend to accumulate and lead to sticky valves, bent pushrods, and damaged pistons.

Because E10 has been generally accepted nationally as the most likely fuel for the foreseeable future, most boating magazines are now prompting their readers to upgrade their boats to deal with its inherent properties.

Among their recommendations are replacing old gaskets, fuel lines and even certain fuel tanks. They also advise replacing conventional fuel filters with 10-micron filter/water separators, and to empty fuel tanks before boats are put into storage.

Yes, boaters should be concerned about using E10, but primarily if they own boats more than 15 years old and haven't taken the necessary steps to make their vessels compatible with its use.

Of course, if H.B. 791 passes into law, it could make the matter moot. But I can't help wondering if the expenses inherent in requiring refiners to formulate, transport, store, and dispense an additional fuel mixture have been taken into consideration.

It could be that boat owners may be better off -- and safer -- by just upgrading their boats to begin with.

Ray Pendleton is a free-lance writer based in Honolulu. To reach him, e-mail raypendleton@mac.com.