This is a pressing question and I think I have some insight on it.  Professor Fred Hochgraf of the University of New Hampshire has conducted testing on E10 fuel.  What he found is that E10 will draw components out of the resin in the fiberglass fuel tank.  The resin components for a black residue deposit on the engine valves which causes them to stick.  Then the usual failure mechanism takes over, the piston hits the valve(s) and stuff breaks and the engine is damaged.

Turns out the chemical in the fiberglass resin is from the “phthalates” family which is used to make the fiberglass less brittle according to Professor Hochgraf.  Of course, this did not happen to the control engine which did not have a fiberglass fuel tank or E10 fuel.

So if your boat has fiberglass fuel tanks, made before 1980, I recommend that you replace them with aluminum or stainless if you can afford it.  These tanks are not affected by the E10 fuel.  The later fiberglass fuel tanks seem to be less suceptible to this problem.  But there is no simple way to determine if your have a problem.  And the E10 fuel is probably here to stay.  Professor Hochgraf’s website is www.nhml.com.

Until next time.

Adam Wells

Certified Marine Mechanic  Why wait?…Service today!

843-602-6545

In addition, the professor found that fractions of the gasoline fuel are disolved into the fiberglass fuel tank wall.  Now when the fuel tank runs low or is empty, a dangerous situation is created since the fuel tank will be filled with air containing oxygen, creating an explosive situation.

Hi Adam here and I have a tip for you.  How long should engine coolant last?  Engine coolant should last about five years.  However, it should be tested to be sure it is still protecting your engine(s).  Use an antifreeze tester, or a refractometer.  The antifreeze should be good down to -32 degrees fahrenheit.

Its also smart to test the coolants rust inhibitor level.  You can get test strips from marine engine suppliers that do this for you.  Just follow the directions that come with the test strip.

So the days are getting longer and soon the sun will be warming the water and the air.  Spring is not that far off.  Until next time, mate.

Adam Wells

Certified Marine Mechanic

We come to your boat.  Why Wait …Service today!

843-602-6545