Fiberglass Fuel Tanks and Ethanol a Corny Solution - 7/28/06

Gasoline refineries are phasing out the use of MTBE which is an additive that oxygenates gas and reduce emissions. They are replacing this additive with ethanol. When using ethanol as an additive in you car or truck you may never notice a difference but in you boat you could have serious problems if you boat uses a fiberglass fuel tank.

E10 fuel which contains 10% ethanol and 90% gasoline was sold at 40% of the gas stations in the U.S. by April of 2006. It will be offered at other gas stations on a set time schedule. In 2005 federal legislation will not provide limits on liability for refiners that used MTBE which was required by the EPA. The result is refineries do not want to extend their liability and are switching to E10 fuel.

Ethanol has been linked to weakening fiberglass gas tanks. Most gas tanks on boats are made from aluminum or plastic. Older boats and high end sport fishers were built with fiberglass gas tanks. Tests have confirmed that resins used in some fiberglass tanks are leaching form the walls of the tanks into the fuel. This resin goes through the fuel system and sticks to valves and other internal engine parts. This buildup of resin deposits may cause bent pushrods and may cause clogged intake valves.

Any boat owner using a fiberglass gas tank will want to consider replacing the tank with aluminum or plastic. To determine the type of resin was used in your tank you want to contact the boats manufacture. Tanks made with vinyl ester resins may resist degradation.

Even if you don’t have a fiberglass gas tank ethanol can act as a solvent and attract water. E10 can lift deposits in fuel tanks and lines. With older boat this can lead to inadequate lubrication and clogged filters. There is also evidence mixing E10 with MBTE gas may cause a gel like substance which could clog fuel injectors and carburetors. It is recommended to burn all the fuel containing MBTE before refueling with fuel containing E10.

E10 will mix with water and will phase separately into its component parts. With enough water present in the fuel could cause the fuel unusable. When ethanol reverts to low octane base stock the normal octane is reduced causing knocking. 87 octane E10 could be reduced to 83 octane fuel.

There is concern with the corrosion of metal tanks in high humidity areas. Marine fuel tanks are vented directly to outside air. Ethanol can draw moisture from the air to the tank. The more water drawn in the more likely corrosion can occur.

Boats storage in winter is another concern. E10 has been estimate to have a shelf life of 60 to 90 days after which the fuel start degrading. This could cause clogged carburetors or injectors.

Fuel-water separators will help remove water but it is recommended to sumping all older boat tanks removing as much water as possible. Changing fuel filters may be required more often. Do not let gas sit in the tank for long periods of time.

America’s Corn Belt produces 9 billon bushels of corn and Canada adds another 350 million bushels each year. The federal subsidy for 51 cents per gallon and surplus corn to produce ethanol is very attractive for American agriculture.

Currently 4.5 billion gallons of ethanol is produced each year. In 2004 vehicles in the U.S. consumed 141 billion gallons of gasoline. It would take 14 billion gallons of ethanol to produce enough E10 for the U.S. at consumption levels equal to 2004. Even when all the 30 ethanol plant being build this year comes on line it will add up to only 6 billion gallons a year. The U.S. will need to import ethanol from countries like Brazil which is the number one ethanol producing country in the world. Brazil produces its ethanol from sugar cane. Producing ethanol from sugar yields eight times the amount of energy that goes into the process. Ethanol produced from corn yield just as much energy as it takes to produce.

It took Brazil over 30 years to develop the agriculture infrastructure to produce 40% of their fuel needs. Most fuel sold in Brazil is E25. Many vehicles run on 100% ethanol.

Minnesota is considering mandating E20 fuel. They will need to apply for a waiver from the EPA. Research conducted by Orbital Engine Company has shown marine outboard engines suffer performance problems when pushed wide open. Other research has found small hand held gas power tools using E20 can overheat and result in engine damage.

Minnesota will need to overcome some issues before mandating E20. The National Marine Manufactures Association plan to inform lawmakers of the possible dangerous effects when adding ethanol to marine engines.

Summarized
Boat U.S.
Volume XI July 2006 page 23
Author Michael Varalaro

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