MARCO ISLAND — Winter visitors might dissipate as the summer heat begins to roll in, but they can unwittingly leave behind some serious sludge.
And they may have to part with some serious green.
That is, if they leave behind cars or boats and don’t take a few extra measures to ensure that gas tanks are properly prepared for summer hibernation.
Marco Island service station owner Keith Pershing of Island Automotive is acutely aware of the necessary precautions, because he services a sizable number of clients who are in a position to leave their cars and boats in storage while they spend their summers up North.
Most simply, Pershing said, water increases corrosion, so tanks should be kept full during storage to minimize condensation on the tank walls.
The alternative would be to bleed the tank dry.
In recent years, the addition of about 10 percent ethanol into fuel mixes has presented problems for the fuel systems in classic cars, Pershing said.
“But, aside from any ethanol ‘problem,’ gasoline stored for extended periods will oxidize — resulting in the formation of gums which contribute to fuel system and engine deposits,” he said.
He went on to explain that gasoline is typically stable for a period of at least 90 days but may be 30 days old when bought.
Thus, people storing vehicles for more than 60 days should add fuel stabilizers — essentially nonalcoholic “antioxidants” that extend the storage life of gasoline.
So an ounce of prevention could be a gallon of cure, Pershing said.
Brand names include Sta-Bil, Star-brite, StarTron and NAPA’s Stor N Start. The newest formulas are specifically made for ethanol-blend fuels.
From a marine point of view, Capt. Marlene Chaplin of Naples City Dock agreed but said the marina has cut out one negative factor in the equation by not supplying gas containing ethanol.
“Even so, we agree that it is still best to top off boats in storage,” said Chaplin, the assistant dockmaster.
Todd DeVries of Cape Harbour Marina in Cape Coral said the marina generally recommends gas stabilizer additives applied to tanks filled about three-quarters with gas.
“We generally don’t top up for dry storage in our barn,” said DeVries, who operates the cranes and boat lifts at the marina.
Marco Island has a strong classic car fraternity, hence the protection of these sometimes expensive vehicles is logical.
“With E-10 a fact in Florida,” Pershing said, “cars and light trucks 25 years or older sitting idle for 60 days or more in Southwest Florida are subject to swings in temperature and humidity.”
Even though environmental goals have forced changes in fuel since the 1980s, the required standards don’t designate the components of the fuel – only what it must do, said Mal Newbourne, a Marco classic car enthusiast and member of the Antique Automobile Club of America (AACA).
“That is, meet environmental standards, and provide fuel at appropriate octane levels,’’ he said. “E-10 is an oxygenated fuel that is the current preferred direction to reach such goals.”
It has been in use for many years with no problems, except that owners of cars built prior to 1980 may experience tribulations.
In this case, he said, owners need to be aware that the fittings such as gaskets and hoses will deteriorate if made of rubber. Alternatives are either Neoprene or elastomers, a polymer with elasticity characteristics.
Because ethanol is capable of being mixed with, and attracts water, there is concern that all metal tanks, unless kept at constant temperature, will collect water.
But, as Pershing said, “constant temperature is not a Florida word.”
Water is heavier than gasoline so the water-ethanol molecule is dragged to the bottom of the tank (phase separation) and separates from the more buoyant fuel molecules.
A gallon of gasoline-ethanol blend containing 10 percent ethanol can suspend nearly 4 teaspoons of water per gallon. With all that water, corrosion and fuel system damage isn’t far behind.
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The local Antique Automobile Club of America Web site is www.naplesmarcoaaca.org