The latest on the ethanol debate

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New reports confirm speculation that the oxygenate is responsible for engine and fuel tank problems

New reports confirm speculation that the oxygenate is responsible for engine and fuel tank problems

It has been a year or so since reports of various fuel-related problems began to trickle into the boating press. Unfortunately, the initial rumors were quickly followed by widespread speculation and a flood of misinformation from those supposedly in the know. Now we have the benefit of detailed reports from credible sources and some serious research that has substantiated the problems and shed some light on their causes.

The most widely reported problems — rough running, stalling, clogged filters, black deposits on engine intake components and failing fiberglass fuel tanks — eventually were attributed to the addition of ethanol to the gasoline sold in most areas of the country. Now it seems more and more likely that most of the reported symptoms are the result of just two basic problems: the presence of semisolids (sludge) in fuel systems and the breakdown of the resins used to manufacture fiberglass reinforced plastic (FRP) fuel tanks. The severity of the problems and their potentially disastrous effects have led to a flurry of investigative activity that has turned up some additional information and verified some early suspicions. Here’s the latest.


In the July issue, we reported on ethanol’s apparent capability to create sludge after separating from the gasoline due to phase separation (“Is ethanol hurting your fuel system?”). But ethanol has another property that can result in filters and fuel systems being clogged with sludge from another source.

Fuel stored in tanks for extended periods of time can break down, lose volatility and coat the components of the fuel system with what is usually called varnish. Some of the varnish and other impurities often collect in a sludge on the interior of the fuel tank, where it can remain for years unless it is roiled up or attacked by another chemical. Jeff Tieger, vice president of Star brite, a manufacturer of boat and engine maintenance chemicals and equipment, says alcohol (ethanol) is such a chemical.

Tieger says alcohol is an unusual coupling agent, one that can bind with both water and petroleum-based materials, making it a very efficient solvent. It is so efficient that it will break up sludge and varnish that had been building up harmlessly in a fuel tank and suspend the chunks in the fuel, where they can be picked up and delivered through the fuel system. The tainted fuel clogs filters, carburetor orifices and injectors, causing rough operation or even putting the engine out of business altogether.

One immediate defense against the problem, as suggested in the July story, is the use of effective primary and secondary filtration. However, the constant need to replace or clean filters is at least inconvenient and could become a safety issue if the need arises at sea. The alternative is to apply some agent, such as an enzyme, that would break the sludge down into pieces that are small enough to pass through the fuel system — including the filters — where they could be burned harmlessly during normal combustion.

Enzymes are proteins that initiate or enhance chemical reactions. They are used in everyday products like laundry detergents, where they help release dirt and stains from clothing so they can be washed away, and they are present in your intestinal tract, where they aid in breaking down foods for digestion. Star brite’s answer to the sludge problem is a multienzyme product called StarTron, which was developed in Japan for high-volume industrial users who couldn’t afford to stop and change filters. Star brite says StarTron users have experienced none of the sludge problems that we now associate with ethanol, even in those areas where a majority of the problems have been reported ( ).

Whatever fuel conditioner, enzyme or other product you choose to combat sludge problems, keep in mind that at first they may loosen a torrent of impurities that can overwhelm your filters, so keep extras on board and be on the lookout for signs of fuel starvation. Once the system rids itself of stored-up impurities, it should be easier to keep clean with the continuing use of the conditioners.

Fiberglass tank damage

The worst early suspicions seem to have been borne out in tests sponsored by BoatU.S. and reported in its safety magazine, Seaworthy ( Ethanol, in its role as an efficient solvent, is breaking down the fiberglass and carrying dissolved styrene into the fuel system, where it passes easily through filters to be deposited on engine intake systems — manifolds and valves — and gels into a sticky black goo. But that contamination is only part of the problem.

The result of ethanol’s attack on affected tanks is a reduction in structural integrity, which eventually will cause the tank to seep, leak and then fail completely. Any of those conditions can result in a catastrophe. There are two critical things you should do if your boat is equipped with fiberglass fuel tanks or you are considering the purchase of one.

1. If possible, contact the boatbuilder or tank manufacturer, even if you have seen no indication of problems, to verify that the tanks were constructed using resins specifically formulated for the storage of alcohol. This requirement only came to light around 1980 and might not have been passed down to the marine industry until much later, if at all.

2. If you can’t get that assurance, you must accept that the boat is a candidate for very careful inspection on a regular basis, with the results of the inspection recorded in a log. Contamination of engine intake systems, gasoline odors on the boat or in the bilge, changes in fuel tank color or resistance to applied pressure are warning signs that cannot be ignored. If possible, drain the tank completely for off-season storage to reduce the amount of time the solvent has to affect it. Unfortunately, the only remedy for a failing tank is replacement, an expensive proposition that can involve cutting into the structure of some boats.

The future

Whether it makes sense or not, ethanol is here to stay. While it currently makes up less than 3 percent of each gallon of fuel, that figure is scheduled to rise to 5 percent by 2012. The boating community is being particularly affected at this point because of the way we use fuel, the damp environment in which we store it, and the material with which some of our tanks are made. The tank issue won’t be solved easily or inexpensively, but there is hope that the day-to-day problems can be alleviated by heightened awareness, careful maintenance or technical solutions, both existing or soon-to-appear. If enzymes or currently available conditioners aren’t the ultimate answer, then someone will develop something that is. The pleasure-boat market is simply too big and lucrative to have its problems go unsolved for long. Stay tuned.

Politics and economics

Like any information processed through the Capitol Hill machine, the case for using ethanol is long on rhetoric and short on logic. Here are some quick facts.

The economics: When used as a fuel, ethanol is low on energy. It takes almost 1.5 gallons of it to equal the energy in a gallon of gasoline, so users’ cost per mile increases and their fuel tanks will have to get larger to maintain range. Many studies indicate that it takes nearly as much energy to produce ethanol as it contains, and its selling price seems to march in lock-step with the price of gas, so there are no savings associated with its use. It is difficult and expensive to deliver because it must be transported by rail or truck. It cannot be sent through pipelines because of its affinity for moisture. At the relatively low usage rates now mandated by the government, nearly 9 million acres of land will have to be dedicated to corn production for ethanol by 2012. Further increases likely would drive up the price of corn and other commodities, affecting the costs of animal feed, dairy products and human food. They also would reduce corn exports, which contribute positively to our balance of international payments.

The politics: At projected rates of use, ethanol will reduce our overall dependence on fossil fuels by only 1 percent or so, perhaps even less, since some energy from fossil fuels is used to manufacture it. The government’s original mandate to use an oxygenate in gasoline — MTBE or ethanol — was designed to force engines of the 1980s to run on a leaner, cleaner fuel mixture. But modern engines with increasingly sophisticated electronic engine control systems are capable of delivering that level of efficiency and clean operation regardless of the makeup of the fuel. The new governmental directive makes no mention of oxygen, mixture percentages or exhaust content. It simply mandates the use of a total of 7.5 billion gallons of ethanol per year as an automotive fuel by 2012, a grand gift, some would say, to subsidized farmers and big agro-business.