Ethanol

Should I be concerned about this new ethanol fuel in the fuel system of my boat?

This is the most common question I am asked day to day by far. Everyone is concerned and to complicate and even amplify that concern it seems that every fuel related problem, and even some that aren't fuel related, are attributed to ethanol. So, what is the bottom line? Is ethanol a problem and how concerned should we be? Here's my take on the situation....

Ethanol isn't a new fuel solution nor is it a new problem. As a fuel it's been around longer than most of us have, longer even than automobiles. In fact Henry Ford used it as an alternative fuel in his first car. After all, gasoline was practically unheard of before automobiles, so, yes, Henry Fords first automobile was also one of the first "Flex Fuel" cars. Our forefathers quickly learned though that gasoline worked out much better than ethanol; it was more efficient with more BTU's per gallon or pound, and it was cheaper to produce. Oil, the raw material, seemed to be abundant as well so ethanol was quickly forgotten as a fuel source for the average automobile, until the first Arab oil embargo came along in the early '70's. Overnight we needed an alternative source of fuel to power our cars and everyone seemed to jump on ethanol again. Gas stations started to pop up all over with signs proudly proclaiming "Gasohol". Gasohol contained up to ten percent ethanol much as it does today, maybe even more, and all was well for a short while. It didn't take long for the ethanol to take affect and fuel system components began to deteriorate. It was a problem in automobiles but the greater problem seemed to be in boats and outboard motors where fuel lines and gasket material were predominantly flexible hoses and neoprene gaskets. Ethanol would disintegrate those parts from the inside out and the industry scrambled to formulate alternative ethanol resistant materials with varying success. This battle went on for a few years with constant upgrades and the accompanying service bulletins. The Coast Guard eventually issued new regulations restricting which hoses could be used and builders of boats and outboards were regulated to reduce the risk of leaks and the resulting fire and explosion hazards. Things gradually got much better but there was still a problem with some of the fuel tanks, and there was amazing resistance in the industry to accept the fact that ethanol and fiberglass fuel tanks simply were not compatible.

Fiberglass tanks seemed to be the answer to many boaters' prayers for a tank that wouldn't corrode. We loved them for a while and didn't want to let go, but I noticed that in fuel systems, carburetors, hoses, anything that came into contact with the fuel from a fiberglass tank serious problems persisted even with all of the updated materials in place. The only logical explanation in my mind was that the fuel was dissolving the inside of the tank and components of the resin were mixing with the fuel causing the problems I was seeing. This was in the mid seventies. Yes, that far back we had ethanol problems. In order to prove my theory in the face of united denial I took a fiberglass tank and cut it into strips for testing. These strips were delivered to an independent engineering test facility. In just a few weeks the results were conclusive. The resin exposed to gasoline was dissolving, and the introduction of ethanol into the mix would speed up the breakdown rate of the resin exponentially based on the ratio of ethanol to gasoline. I'd proved my theory but fiberglass tanks remained in use for years to come partially because the use of ethanol waned in the next few years. Again we learned that straight gasoline was simpler to produce, less expensive, and more efficient than ethanol.

Now, years again later we are back facing a predominance of ethanol in gasoline. For the most part the fuel systems in boats produced in the last twenty years or so are compatible with ethanol fuel, including the tank material, hoses, filters, and gaskets. Engines themselves are designed to run on the blend. But does this mean we don't have anything to worry about? I'm afraid not. Ethanol is still corrosive and a powerful solvent. It has the ability to loosen deposits in older fuel systems resulting in clogged filters or worse. It also shortens the life of the best hoses and gaskets and even corrodes the inside of some tanks, but as bad as all of that can be it's not the worst of what can happen with ethanol laced fuel. With good materials and a clean tank most of those problems can be all but eliminated. The biggest problem that I've seen is that ethanol absorbs moisture directly from the air.

Since the first fuel tank was introduced ever in history there has been the risk of condensation depositing a volume of water in the fuel over time. That still exists today but in reality the volume is minute and the time frame required is a long while. This happens when the contents of the tank goes through the normal heating and cooling cycle of a typical day; in the heat of the day fuel expands pushing air out of the tank. In the evening the fuel cools and contracts pulling cooler and moist air into the tank. Cooling causes condensation of the moisture and the condensation clings to the walls of the tank. The resulting water settles and accumulates at the bottom of the tank being heavier than gasoline. This relatively minor amount of water could be effectively removed with a typical water separating fuel filter, or even harmlessly removed with one of many fuel additives. With ethanol in the mix though those days are gone.

Fuel tanks still go through the breathing process and there is still the same level of condensation but the water doesn't settle to the bottom anymore. Water readily mixes with ethanol, therefore the water is suspended in the fuel, much the same way it used to be suspended with fuel additives. In fact, most fuel additives for straight gasoline are mostly ethanol. The differences is in quantity. We never put as much as ten percent fuel additive in a tank of gasoline so the fuel has much more ability to absorb water than treated gasoline. In addition to the condensation of water ethanol has the ability to absorb moisture directly from the air bypassing the condensation step. This absorption dramatically speeds up the water accumulation process shortening the shelf life of stored fuel to only a few months, or even weeks before a phenomenon called phase separation takes place.

In phase separation the ethanol reaches its water absorption limit where it becomes too heavy to remain suspended in the gasoline, and it simply falls to the bottom of the tank as a water/ethanol mix. The bottom of the tank is where the fuel pick up line is of course, so the next time the engine is run it will be picked up and fed into the engine where the engine will fail to continue running. If no harm is done initially but the water/ethanol mix is left in the engine's fuel system long enough without being flushed, irreversible and/or expensive engine repairs can be needed. If the water/ethanol mix remains in the tank long enough another new problem can develop. As odd as it sounds organic growth can now begin in the fuel tank. If you think about it that's not as odd as it at first sounds. Ethanol is an organic compound, and it's mixed with the source of all life; water. Mold and fungus now have a fertile bed to grow and this stuff can clog the best fuel filter in short order, not to mention the havoc it can cause if it gets into a fuel injection system on the engine.

In short, to answer the question, "Do I have anything to worry about with ethanol fuel in my fuel tank?", the answer is yes, no matter how good the system is or what the tank is made of. If the tank breathes air phase separation will eventually take place.

How do we cure the problem after it's occurred and how do we prevent it?

Curing the problem may be the simpler answer. The key is to remove all of the fuel from the system; all being the key word. If only a minor amount is left it can be enough to foul the filter and injectors again so everything has to be removed from the tank and the tank should be dried out. This can't be accomplished by simply using the fuel supply pick up and hose attached to the tank. You need to go in through the fuel sender hole by removing the sender and angling the tank so that all the fuel can be siphoned from the tank, then the tank should be allowed to dry completely. All of the fuel should be properly disposed of. Do not try to separate the gasoline from the water/ethanol mix. Because the ethanol is part of the octane of the gasoline the remaining pure gasoline is not safe to use without risking serious internal engine damage which can result from pre-ignition and detonation. Once the tank is completely clean and dry refill with fresh gasoline, then flush all the lines and install a new filter. Be sure to flush all the lines on the engine as well.

The question of how to prevent the water absorption and resulting phase separation is almost impossible to answer with certainty. Additives are on the market and have been for several yeas now which claim to be effective in stabilizing ethanol blended fuel. Many people claim that they work and I hope they are right. I have not personally had an opportunity to test any of them to prove to my complete satisfaction that they are as advertised though. I have some dependable contacts who are working on that project scientifically testing the additives and I anxiously await their results which I intend to post as an addendum here with references.

I have my opinions as to the viability of ethanol as a green fuel alternative and the political ramifications or undertones of its use but that may be best saved for another discussion.

thanks,

Tom