Older boats using ethanol-based gasoline are constantly ending up at the Flat Creek Marina service area. Newer equipment on boats, like fuel filters, can help prevent the problems associated with using the fuel blend. Above: Boats at the Flat Creek Marina dock, awaiting a more pleasant day to be out on the lake, rather than a rainy one. LAKE PALESTINE - More and more gas stations are serving up a blend of ethanol and gasoline, nicknamed gasahol. While most cars run reasonably well on the blend, infrequent gas fill-ups for antique cars, power tools and older boats don't work quite as well.

A blended ratio of 10 percent ethanol with gasoline acts as a solvent in older fiberglass and metal tanks. As the dissolved resins in the fiberglass tank make their way through the fuel line and working parts of the engine, it can foul up carborators and bring motors to a standstill.

In metal tanks, it cleans out the gunk and varnish that's accumulated over the years and sends those downstream to clog parts. Ethanol also weakens rubber parts such as hoses and gaskets.

Another issue for boaters is the fact that ethanol attracts water, from condensation in the tank and from water vapor entering through the tank vents.

When a fill-up is not completely used and sits for periods of time, the fuel can go into phase separation. The water and dissolved solids in the tank sink to the same level as the fuel intake and when the motor is finally restarted this accumulation can wreck havoc with an outboard engine, explains outdoor writer Angus Phillips in a November, 2007 article.

"When you crank up the motor, the crud is sucked into the carburetor or injectors and plugs things up," he writes.

BoatU.S. warns boaters that once phase separation has occured in E10 gasoline, additives and water separators can't help. The only remedy is to have the gas and ethanol/water professionally removed from the tank.

Scott Cook of the Boat Owners Association of the United States confirms ethanol's solvent properties in older boats. "We have plenty of evidence of fuel tanks degrading on older vessels to the point that they can totally destroy an engine with sludge," he said.

"Usually, by the time it degrades to the point of a leak, the engine has conked out or is dead, and someone has realized that something is seriously going on," Cook said.

While advice from boat mechanics vary on how to compensate for the use of E10 in older boats, using the regular unblended gas seems the best preventative measure.

Flat Creek Marine and Lake Palestine Resort have different experiences with this.

Charlie Miller, Flat Creek Marine manager, said the older model boats are suffering from ethanol-based fuel.

"It's cutting stuff loose and sending it to the carburetors," Miller said.

He added many of the problems come from older models and equipment.

Jeff Wygren, the marine's service manager, said the old carburetors can't handle ethanol's cleaning effect, and gunk will get stuck, clogging the intake.

Miller said old fiberglass fuel tanks can actually break down when in prolonged contact with ethanol fuel.

There are precautions boat owners can take to avoid these issues. The most obvious one is to simply purchase newer equipment designed to handle ethanol fuel.

Another precaution is to not mix the two types of fuel available for boats.

"If you mix the two gases together, it'll create crystals in the system," Miller said. "I saw a motor that had this, and it took several hundred dollars to fix it."

In addition, when putting a boat away for an extended period of time, such as during the winter, it is wise to totally empty the gas tank. If a trip is necessary afterward, fill the tank with only as much gas as is needed.

Above all, follow the manufacturers' recommendations for their specific models, as each manufacturer can have different recommendations.

Lake Palestine Resort confirmed newer boat models show very few, if any, problems with ethanol-based fuel, which is the type of gas it serves.

While advice on what to do varies, here's what the folks at www.driving ethanol.org/ ethanol_vehicles/boating.aspx say about changing to the E10 ethanol blend for boats: Before switching from regular gas to E10 for the first time, check for the presence of water in the fuel tank. If any is found, dry the tank completely. Fill your tank as full as possible to limit the flow of air into and out of the vent, thus reducing the chance of adding water to the tank through condensation.

It is critical to minimize water in the gas tank. If too much water is present, it will cause ethanol to separate from the gasoline (phase separation), which can cause stalling and even engine damage.

The Transom Newsletter put out by iBoats.com adds boats with metal tanks should be inspected for signs of corrosion. These and older fiberglass fuel tanks should consider replacement with a new plastic tank.

Polyethylene fuel tanks are not affected by ethanol, age well and are incredibly durable. Any boat with a fiberglass gas tank that was not specifically designed for ethanol, especially ones built before the mid-1980s, are particularly susceptable. Short of replacement, older fuel tanks should be professionally cleaned beforehand.

Inspect the fuel filter frequently. Stock your boat with extra filters and place the old filter in a metal container to prevent spillage on the deck. Know how to replace the filter in case it clogs while you are on the water.

Replace fuel filters regularly when burning the first several tanks of E10. A 10 micron filter is recommended. Inspect fuel lines and gaskets throughout the fuel system. The Transcon newsletter also recommends tinkering with the idle adjustment screws, high-speed air/fuel adjustments as rough running may occur on switch-over to the newer fuel.

During winter storage or extended storage, boaters from Minnesota (the land of lakes, boasting one boat for every six people) recommend topping off a boat's fuel tank to 95 percent full to leave room for expansion and to cut down on water accumulation during periods of inactivity.

Also, use a fuel stabilizer. Add it at the time of fill-up, anytime the fuel may sit for more than a month.

While this organization recognizes that older boats may "experience significant difficulties with E10 ethanol," it says these difficulties "affect less than 1 percent of the 13 million registered boat owners in this country."

Technical advisor for BoatU.S. Bob Adriance says, "We found that once the transition to E10 ethanol is complete and the first few tanks of ethanol-enhanced fuel are run through the system, the issues with E10 are manageable. "We've also seen that owners who use their boats frequently and cycle through fuel have fewer problems than those whose boats are only occasionally used," he added.