As much as I dislike ethanol in our fuel it seems that it is here for a while so we may as well learn to live with it as well as we can. To minimize the adverse affects of the ethanol many companies have developed fuel additives to protect the fuel. They all claim to be the best and the answer to our needs but I want to know from personal experience which ones work and which ones don't, and maybe even which is the best. To accomplish that goal I started a hands on, side by side test of various brand name additives in known ethanol laced gasoline. That test was started on 10/1/10, so it's been one year to date that the test has been running. The results were interesting.
First step was to verify that I had an ethanol/gasoline mix. I bought a gallon at the local Hess station and poured a small quantity in a glass jar. With an eye dropper I added a few drops of water. The drops fell to the bottom of the jar as beads but as I stirred the fuel the water suspended in the fuel and did not settle out. I repeated the procedure several times before I reached saturation where it would no longer suspend, and then I witnessed phase separation where the ethanol/water mix fell to the bottom of the jar. Sure enough, the quantity of mixed fluid on the bottom of the jar was quite a bit more than the quantity of water I'd added to the fuel assuring me that I had ethanol in the fuel.
Step two: I took seven equal sized jars and added an equal amount of fuel in each jar. Then I took six brands of fuel treatment and added the recommended quantity of each in the fuel, leaving one jar with pure gasoline/ethanol mix. The jars were vented and left in an open air garage as if stored in a vented container, or the fuel tank of the typical boat. After one year I have what I consider to be valuable results.
Brands tested:
Stabil
Stabil Marine
Startron
Valvtect
CRC Phase 4
BRP 2+4 for Ethanol fuel
Symptoms tested for and noted:
Evaporation. As fuel sits it slowly evaporates leaving a sticky residue which can clog carburetors and injectors. If the additive can prevent this you'll save hundreds of dollars in rebuilds and clean up. Evaporation also robs the fuel of needed hydrocarbons and such degrading the fuel of BTU's and octane. It's obviously better if we can prevent this and have a use able fuel after a reasonable storage time. Based on past experience with stored fuel I gave the evaporation protection the highest importance.
Moisture absorption protection. By now most of us know that ethanol fuel is very susceptible to water absorption which creates all sorts of havoc in the fuel systems of any gasoline engine. If we can stop or slow that process the additive is wonderful stuff.
Inhibit organic growth. Most do not know of this phenomenon but when water is absorbed into ethanol the result is an organic based mix quite hospitable to organic growth such as mold and mildew. If you've ever siphoned off the mix from the bottom of a fuel tank after phase separation has taken place and noticed the little flakes floating around in it, that's what I'm talking about here. The best way to slow this is obviously to slow the water absorption but it's important to slow the growth of the organics as well since moisture absorption to some extent is inevitable.
This covers the methods used and the test criteria, now for the results.
Startron came in first with the best protection against evaporation, crystal clarity of the mix after one year suggesting no organic growth, and no phase separation.
Valvtect scored a strong second with only minimal clouding of the mix, no separation, and evaporation protection equal to Startron.
Stabil Marine with excellent protection against evaporation, some clouding, and no separation.
The others were a mixed bag. None of them showed any sign of phase separation. Some were extremely cloudy. One offered no better protection against evaporation than the straight gasoline. No need to name names here since my mission is accomplished. So many folks ask what I would recommend and the three mentioned here get that nod. I'll never store over a year and all of them did a great job up to that point.
Friday, September 30, 2011
Wednesday, August 24, 2011
Fuel tank clean out procedure.
Since the first fuel tank was introduced 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 generally long. 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.
I've spoke with many individuals with water in the fuel issues through the years but with the instroduction of ethanol in our fuel this problem has increased dramatically. Most people suspect a leaking fuel tank as the cause, or possibly a leaking fuel cap or lines. This can be the cause and should be investigated but it's really not likely. The quantity of suspected water in the tank is usually in the gallons. Think about how long it would take for a gallon of fuel to get into a tank from rain even if the fill cap were left off. A hole in the tank also most often results in a fuel leak instead of water intrusion. The only spot on a tank that occasionally allows a considerable volume of water intrusion is the gasket under the fuel level sending unit on top of the tank.
Curing the problem takes some work but most people can do it themselves. 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 or carbs 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. Angling the tank can be accomplished easily if it is on a trailer by raising the front of the trailer causing the contents to flow to the rear, then you may need to raise one wheel at a time to be sure nothing is trapped behind a baffle. 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.
Another common scenario is when the tank is pumped, filled with fresh fuel and flushed, and everything is fine, but comes right back in just a few weeks. This is when most are convinced there is a leak allowing water into the tank, and it can be, but again ethanol may be the explanation. If the tank was pumped but part of the water/ethanol mix was missed, and then fresh fuel is pumped on top of that, you now have enough ethanol in the fresh fuel to suspend the water that is left in the tank, but it is near saturation level where phase separation can again occur. Under these circumstances the time frame it takes for the problem to return is dramatically shortened. If it comes right back, you most likely didn't get it all.
Why is there so much of this mixture? It's got to be a leak to get this much; right?
Remember, ethanol laced gasoline is around a 10/90 % mixture. If your tank holds 20 gallons of fuel for instance, it can contain 2 gallons of ethanol. When the ethanol absorbs enough water and separates out of the fuel in this tank the resulting sediment would exceed two gallons which will appear to be a huge quantity of water. This is a possible logical explanation for the huge quantities I'm hearing of in the fuel tanks.
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.
I've spoke with many individuals with water in the fuel issues through the years but with the instroduction of ethanol in our fuel this problem has increased dramatically. Most people suspect a leaking fuel tank as the cause, or possibly a leaking fuel cap or lines. This can be the cause and should be investigated but it's really not likely. The quantity of suspected water in the tank is usually in the gallons. Think about how long it would take for a gallon of fuel to get into a tank from rain even if the fill cap were left off. A hole in the tank also most often results in a fuel leak instead of water intrusion. The only spot on a tank that occasionally allows a considerable volume of water intrusion is the gasket under the fuel level sending unit on top of the tank.
Curing the problem takes some work but most people can do it themselves. 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 or carbs 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. Angling the tank can be accomplished easily if it is on a trailer by raising the front of the trailer causing the contents to flow to the rear, then you may need to raise one wheel at a time to be sure nothing is trapped behind a baffle. 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.
Another common scenario is when the tank is pumped, filled with fresh fuel and flushed, and everything is fine, but comes right back in just a few weeks. This is when most are convinced there is a leak allowing water into the tank, and it can be, but again ethanol may be the explanation. If the tank was pumped but part of the water/ethanol mix was missed, and then fresh fuel is pumped on top of that, you now have enough ethanol in the fresh fuel to suspend the water that is left in the tank, but it is near saturation level where phase separation can again occur. Under these circumstances the time frame it takes for the problem to return is dramatically shortened. If it comes right back, you most likely didn't get it all.
Why is there so much of this mixture? It's got to be a leak to get this much; right?
Remember, ethanol laced gasoline is around a 10/90 % mixture. If your tank holds 20 gallons of fuel for instance, it can contain 2 gallons of ethanol. When the ethanol absorbs enough water and separates out of the fuel in this tank the resulting sediment would exceed two gallons which will appear to be a huge quantity of water. This is a possible logical explanation for the huge quantities I'm hearing of in the fuel tanks.
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