Continued problems have been reported by boaters using ethanol blended gasoline. Mitigate many of these issues with a little proactive work on your boat.
What is the problem?
Recent initiatives aimed at improving air quality have negatively impacted many boaters. The U.S. Environmental Protection Agency (EPA) requires the use of oxygenated gasoline to improve air quality. Many regions use Methyl Tertiary-Butyl Ether (MTBE), but ethanol is replacing it in many areas due to its own environmental problems. MTBE has links to cancer and easily leaks into groundwater aquifers. Ethanol use as a powerboat fuel can cause a number of headaches including fiberglass fuel tank failure, fuel system blockages, engine damage, and increased fuel contamination.
What happens to your boat?
Ethanol is a blend of gasoline and ethyl alcohol. Ethyl alcohol is an excellent solvent and is hydroscopic, that is it adsorbs water. Acting as a solvent, ethanol can damage the sealants used on older fiberglass fuel tanks. The dissolved sealants can be ingested by the engine which can cause damage and fuel leaking from a tank into the bilge is a fire hazard. Fuel tanks built of other materials are not immune to having a problem. Ethanol has a cleaning effect on tanks that releases fine metallic particles which will pass through most fuel filters. The dissolved metals will clog fuel injector nozzles and carburetors. Ethanol added to a fuel tank contaminated with water will cause expensive repairs. The water in the tank will combine with the ethyl alcohol to produce a noncombustible layer of liquid in the tanks that will stop most engines cold.
What can you do to protect your boat?
The jury is still out on the definitive protection plan for ethanol fuel use. The following are some suggestions that have helped other boaters:
Boats built prior to 1984 should have their fiberglass fuel tanks and lines replaced with modern equivalents before ever using ethanol. This will immediately eliminate almost certain failure of these older fuel tanks and components.
Historically boaters were told to leave their fuel tanks full in the winter. Initially the industry thought that it might be more prudent to empty the tanks and thoroughly clean them prior use in the following boating season. BoatU.S. is recommending that this practice not be followed.
Use a good water separating fuel filter and carry several spare cartridges for it. Racor Filter manufactures a good product for this purpose.
Try to avoid mixing gasoline blended with MBTE and ethanol. Use up the MBTE blended gasoline in your tank and insure the tank is clean prior to adding ethanol to it.
Ethanol fuel has a very short shelf life compared to the gas we are used to burning. Limit your fuel onboard to what's needed in the next two weeks.
It appears the best defense for boaters in the use of ethanol fuel is to keep your fuel tank clean of water and use adequate filters. There may be more improvements in engine and fuel system technology that will address this problem. While your fueling your vessel, remember to review accepted industry Safe Boat Fueling practices. I will update our readers at Suite101 as the situation develops.
The copyright of the article Ethanol Fuel Problems for Boaters in Boating & Sailing is owned by Alan Sorum. Permission to republish Ethanol Fuel Problems for Boaters in print or online must be granted by the author in writing.
When winterizing your boat do not over fill the fuel tank With the
proliferation of E10 gasoline, a mixture of 90% petroleum and 10% ethanol,
there has been a lot of discussion on the issue of phase separation during
the winter lay up.
Phase separation is caused when water enters
the fuel tank and causes the ethanol to separate from the petroleum and
absorb the water. This leaves the tank with a lower layer with a mixture of
mostly high octane ethanol and some water and a upper layer of low octane
petroleum fuel. Both of these can cause various problem.
The
answer that I have read on various message boards is to fill the fuel tank
to the very top. The reasoning is by toping off the tank so its full to the
very top you will prevent air from being in the tank. By preventing air
from being in the tank you will prevent condensation from forming in the
tank and this will prevent water from getting into your fuel, thus
preventing phase separation.
OK, here is the question:
Your boat has a 200 gallon tank. The tank is near full. Its
been 30 degrees F for several days so by now your gas is at 30 degrees. You top off the tank so it's full. Spring comes. The temperature rises to
over 70 degrees for several days. This causes your fuel temperature
to rise to 70 degrees. How much gasoline will overflow and spill out
onto the ground?
Answer: 5.52 gallons will spill out on the
ground.
The "coefficient of expansion." Called
the API factor for gasoline is .00069/degreeF Total Temperature change was
40 degrees 200 (gallons) * 40 (temperature change in degrees F) * API
factor .00069 = 5.52 gallons
I suggest you do fill your tank but
do not top it off. Leave some room for fuel expansion.