Hi, My boat here in Puget Sound stays in the water all year round. Usage in the winter is less (and there's more wind), so I may only go through half a tank between November and March. Am I supposed to add any treatment (biocide) to the diesel during this period? Since I didn't, should I do anything now? This fuel treatment thing ( like many other things boat ) seems to be rather full of lore. Thanks Thanks much Cat
Diesel: To treat or not to treat
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Critters
If you have critters, you will just be killing them. They clog your filter just as effectively dead or alive. I just read a good article on this. Maybe DIY Boat, or Good Old Boat. I have heard of people not doing anything for years and not having a problem until it gets rough. Lots of stuff and water can accumulate below the pickup in your tank before you will suck it up into the filter. I installed an inspection/cleanout port in mine and I drain the tank once a year and dump the diesel into my home furnace(filtered). Tim
If you have critters, you will just be killing them. They clog your filter just as effectively dead or alive. I just read a good article on this. Maybe DIY Boat, or Good Old Boat. I have heard of people not doing anything for years and not having a problem until it gets rough. Lots of stuff and water can accumulate below the pickup in your tank before you will suck it up into the filter. I installed an inspection/cleanout port in mine and I drain the tank once a year and dump the diesel into my home furnace(filtered). Tim
Critters....
...live in water. If you are not having any water problems in your fuel, you won't have any critters to kill. If you are not sure, adding a pinch of biocide (it's easy to believe "more is better", but that ain't so...)probably would be a good idea. Keeping your fuel clean, by changing filters at least once per season and perhaps prefiltering it with a West or similar water/crud separating filter before it goes into your tank, will go a long way in avoiding common fuel problems. And don't forget to inspect and or replace the "O" ring in your fuel filler cap as I believe that's where most fuel tanks pick up water.
...live in water. If you are not having any water problems in your fuel, you won't have any critters to kill. If you are not sure, adding a pinch of biocide (it's easy to believe "more is better", but that ain't so...)probably would be a good idea. Keeping your fuel clean, by changing filters at least once per season and perhaps prefiltering it with a West or similar water/crud separating filter before it goes into your tank, will go a long way in avoiding common fuel problems. And don't forget to inspect and or replace the "O" ring in your fuel filler cap as I believe that's where most fuel tanks pick up water.
Fresh Fuel
Trying to keep the tank only as full as needed for a couple or three months helps keep bugs at bay. I keep about 1/4 tank which is about 5 gallons in my tank. That is enough for about 10 hours of motoring. In my three and a half years of doing this I've only had trouble once and that was after refueling in Mobile. After using that tank and having to change filters I haven't had any trouble. A guy at the dock told me...too late after I'd already bought a half a tank.. That they had been having fuel problems at the dock and early that day some fuel polisher was working on the dock's tanks. I do use biocide but as said previously keeping water from leaking in around O-rings etc is probably more important than adding biocides. By keeping fresh fuel in the tank bugs have less time to grow. With a full tank and little use bugs can literally have years to grow. My boat is used year round. But if I hauled out I'd empty my fuel tank each fall. Bugs can't grow in a dry empty tank.
Trying to keep the tank only as full as needed for a couple or three months helps keep bugs at bay. I keep about 1/4 tank which is about 5 gallons in my tank. That is enough for about 10 hours of motoring. In my three and a half years of doing this I've only had trouble once and that was after refueling in Mobile. After using that tank and having to change filters I haven't had any trouble. A guy at the dock told me...too late after I'd already bought a half a tank.. That they had been having fuel problems at the dock and early that day some fuel polisher was working on the dock's tanks. I do use biocide but as said previously keeping water from leaking in around O-rings etc is probably more important than adding biocides. By keeping fresh fuel in the tank bugs have less time to grow. With a full tank and little use bugs can literally have years to grow. My boat is used year round. But if I hauled out I'd empty my fuel tank each fall. Bugs can't grow in a dry empty tank.
I keep my tank full all the time...
I top off by going to high volume truck station near the marina using a 5gal container. If I need more than that I use the marina fuel...not as clean but don't want to be carrying 40lbs of fuel back and forth. Then, again humidity in S California is less than your area....maybe that is why I haven't had any problems so far.
I top off by going to high volume truck station near the marina using a 5gal container. If I need more than that I use the marina fuel...not as clean but don't want to be carrying 40lbs of fuel back and forth. Then, again humidity in S California is less than your area....maybe that is why I haven't had any problems so far.
Dmned if you do and damned if you don't..
Yes, bugs grow in water and feed on diesel fuel at the thin interface between the liquids. Biocides kill bugs whose carcasses collect at the bottom of the tank forming sludge which in turn may block filters and fuel lines. No biocides allow uncontrolled growth of bugs which naturally die with the same consequences or worse because of the uninterrupted nature of the process. Keeping the water level at a minimum is one way of regulating unchecked growth. This is one positive argument for keeping you tank full. In high humidity areas like in our location the unfilled volume inside a tank will fill with ambient humid air in repeated cycles of 24 hours as temperatures fluctuate during the period causing condensation. The other side of the problem is that sailors do not use much fuel and hydrocarbon degradation becomes a problem. Fuel stabilizing additives help this condition. Petroleum industry practices recommend that the fuel tank be sized according to the consumption which is not practical for a sailboat as our tanks are way to big for daysailing and way to small for passage making. They also recommend the use of stabilizers and biocides with a way of removing impurities (filters and water separators). They further recommend tanks be maintained full or at least not less than 50% full. Fuel degradation starts right after crude processing and they claim a degradation of 26% after a 28 days period. I guess every 28 days it degrades 26% from it starting date on that 28 day period. After what time it becomes unusable I guess it varies from application to application. I guess I have had more problems from old fuel than from dirty fuel. After weighing all the information I formulated a plan, Keep the tank half full while periodically bleeding water out of the system, add biocide and stabilizers and most important to use the boat frequently. (perfect excuse for the Admiral). Have had my share of fuel related problems through the years and anticpate I will continue to have them as it is the nature of the beast but if I can reduce them to a single incident every 3-5 years is not bad. Even the most perfect plan can be hijacked by the unfortunate purchase of bad fuel. Good luck.
Yes, bugs grow in water and feed on diesel fuel at the thin interface between the liquids. Biocides kill bugs whose carcasses collect at the bottom of the tank forming sludge which in turn may block filters and fuel lines. No biocides allow uncontrolled growth of bugs which naturally die with the same consequences or worse because of the uninterrupted nature of the process. Keeping the water level at a minimum is one way of regulating unchecked growth. This is one positive argument for keeping you tank full. In high humidity areas like in our location the unfilled volume inside a tank will fill with ambient humid air in repeated cycles of 24 hours as temperatures fluctuate during the period causing condensation. The other side of the problem is that sailors do not use much fuel and hydrocarbon degradation becomes a problem. Fuel stabilizing additives help this condition. Petroleum industry practices recommend that the fuel tank be sized according to the consumption which is not practical for a sailboat as our tanks are way to big for daysailing and way to small for passage making. They also recommend the use of stabilizers and biocides with a way of removing impurities (filters and water separators). They further recommend tanks be maintained full or at least not less than 50% full. Fuel degradation starts right after crude processing and they claim a degradation of 26% after a 28 days period. I guess every 28 days it degrades 26% from it starting date on that 28 day period. After what time it becomes unusable I guess it varies from application to application. I guess I have had more problems from old fuel than from dirty fuel. After weighing all the information I formulated a plan, Keep the tank half full while periodically bleeding water out of the system, add biocide and stabilizers and most important to use the boat frequently. (perfect excuse for the Admiral). Have had my share of fuel related problems through the years and anticpate I will continue to have them as it is the nature of the beast but if I can reduce them to a single incident every 3-5 years is not bad. Even the most perfect plan can be hijacked by the unfortunate purchase of bad fuel. Good luck.
another crntroversial topic
Hope this one doesn't degrade like old fuel... Benny - could you be more specific regarding where you obtained those figures on fuel degredation? Filling tanks often to avoid condensation at the expense of ending up with old contaminated fuel - these arguments have been around a long time and there are some myths associated with some folks' opinions which is the best strategy. I must admit to doing it both ways, i.e., filling over winter and not doing so, and my personal experience is it makes no apparent difference. The test on which I base that opinion, which is clearly subjective, is to remove about a pint of fuel from the tank bottom each spring to see what is collected and remove any sediment or water. Each time, there has been crud (scientific term) regardless of how full/empty the tank was. This convinces me the only definitive solution is to move someplace where I can use the boat continuously.
Hope this one doesn't degrade like old fuel... Benny - could you be more specific regarding where you obtained those figures on fuel degredation? Filling tanks often to avoid condensation at the expense of ending up with old contaminated fuel - these arguments have been around a long time and there are some myths associated with some folks' opinions which is the best strategy. I must admit to doing it both ways, i.e., filling over winter and not doing so, and my personal experience is it makes no apparent difference. The test on which I base that opinion, which is clearly subjective, is to remove about a pint of fuel from the tank bottom each spring to see what is collected and remove any sediment or water. Each time, there has been crud (scientific term) regardless of how full/empty the tank was. This convinces me the only definitive solution is to move someplace where I can use the boat continuously.
yachtsurvey.com
David Pascoe a marine surveyor/engineer wrote an article about the myth of condensation in fuel tanks. Go to yachtsurvey.com and look up the article. He has several good articles on boats. The bottom line is that water doesn't get into diesel fuel tanks from condensation. Even if you believe that you get a gallon/day of water from condensation fresh fuel makes sense. A water/fuel separator can easily handle water in your fuel. It's the bugs that clog everything. It's getting old that hurts the fuels quality even if there are no bugs. Ideally we'd have a 5 gallon tank that we use most of the time with a 20 gallon tank for cruises. Well 20 gallons gives me about 200 miles of motoring which will work for me. Maybe a hard 5 gallon tank and a 20 gallon flexible tank??
David Pascoe a marine surveyor/engineer wrote an article about the myth of condensation in fuel tanks. Go to yachtsurvey.com and look up the article. He has several good articles on boats. The bottom line is that water doesn't get into diesel fuel tanks from condensation. Even if you believe that you get a gallon/day of water from condensation fresh fuel makes sense. A water/fuel separator can easily handle water in your fuel. It's the bugs that clog everything. It's getting old that hurts the fuels quality even if there are no bugs. Ideally we'd have a 5 gallon tank that we use most of the time with a 20 gallon tank for cruises. Well 20 gallons gives me about 200 miles of motoring which will work for me. Maybe a hard 5 gallon tank and a 20 gallon flexible tank??
I would think that if condensation were a real
problem then it would occur in automobile fuel tanks also. I drive a twenty yeat old car that has been in my possesion for fourteen years. I refill the rank when it gets below 1/4 full. I live in Maryland the home of weather extremes. Very warm one day cold and foggy the next. Sub freezing weather will freeze water in fuel lines and stop the engines. Fifty years ago it was fairly common. I haven't experienced nor have I heard of it happening to anyone in the last fifteen years. Do they add enough alcohol to absorb the water or are they selling gasoline with less water? We used to buy "Dri-Gas" basically an alcohol product that was added to the tank each fall and again in late winter.
problem then it would occur in automobile fuel tanks also. I drive a twenty yeat old car that has been in my possesion for fourteen years. I refill the rank when it gets below 1/4 full. I live in Maryland the home of weather extremes. Very warm one day cold and foggy the next. Sub freezing weather will freeze water in fuel lines and stop the engines. Fifty years ago it was fairly common. I haven't experienced nor have I heard of it happening to anyone in the last fifteen years. Do they add enough alcohol to absorb the water or are they selling gasoline with less water? We used to buy "Dri-Gas" basically an alcohol product that was added to the tank each fall and again in late winter.
Powerboat NO.. Sailboat YES
If you burn up your fuel in a month or two they why treat it. You will just be burning up the treatment which is bad for the engine.....
If you burn up your fuel in a month or two they why treat it. You will just be burning up the treatment which is bad for the engine.....
Re: I would think that if condensation were a real
very good point but you can put the hat back on!
very good point but you can put the hat back on!
analogy to car fuel tanks
isn't a good one since all contemporary automobile tanks are a closed vented system since the early 1970s making it almost impossible for condensation to form in the tank. Having said that, I do agree that the condensation problem is more myth than problem plus, if you think about which is worse, contaminated fuel or water, the latter is much easier to deal with.
isn't a good one since all contemporary automobile tanks are a closed vented system since the early 1970s making it almost impossible for condensation to form in the tank. Having said that, I do agree that the condensation problem is more myth than problem plus, if you think about which is worse, contaminated fuel or water, the latter is much easier to deal with.
I doubt it Ross
Not unless you somehow could manage to place a sufficiently large enough volume of desiccant to adsorb the max volume of water expected (whatever that might be), and also know when and how often to change it to add new desiccant. Another consideration is that once completely saturated, it's efficacy is gone in which case it could trap or even add moisture to the system. I don't believe silica gel is a desiccant regardless - if you wanted to try it, use calcium chloride or oxide which is the stuff typically marketed in marine stores but much cheaper at the hardware store. I'm trying an experiment this winter. Have my old but still intact aluminim holding tank which I dried and filled it half full with No.2 oil in the fall It is sitting outside my garage for the winter full. In the spring, I plan to remove the fuel and measure how much water condensed inside.
Not unless you somehow could manage to place a sufficiently large enough volume of desiccant to adsorb the max volume of water expected (whatever that might be), and also know when and how often to change it to add new desiccant. Another consideration is that once completely saturated, it's efficacy is gone in which case it could trap or even add moisture to the system. I don't believe silica gel is a desiccant regardless - if you wanted to try it, use calcium chloride or oxide which is the stuff typically marketed in marine stores but much cheaper at the hardware store. I'm trying an experiment this winter. Have my old but still intact aluminim holding tank which I dried and filled it half full with No.2 oil in the fall It is sitting outside my garage for the winter full. In the spring, I plan to remove the fuel and measure how much water condensed inside.
Tank condensation .....
Oil is either distilled or cracked at high temperature; the high heat of cracking/distilling/formation and recovery renders the fuel 'bone dry'. Dry fuel picks up moisture from the ambient atmosphere by absorbtion/adsorbtion ... a physical/chemical equilibrium. If you are getting condensation in the fuel it means that the fuel is already 'saturated' with water vapor and not all off this is 'free' water but includes water as an emulsion, ad/absorbed water as well as free water. Tanks by themselves do not promote 'condensation'; evidence of condensation only shows that the fuel is already saturated with water. Ways to prevent 'condensation': 1. NO fuel in the tank or a minimum amount, 2. a vacuum/pressure rated tank .... with a valve on the vent that's closed when not drawing down fuel. 3. a desiccant chamber (but that will soon also absorb oil vapor also .... the heat regeneration process will 'coke' the oil into the surface area of the desiccant) - tricky. I use a desiccant chamber of activated alumina on the vent, ...... the regeneration of the desiccant is difficult for a 'consumer'. This desiccant chamber is clear plastic 'cylinder' and has a 'trim' section/layer of dyed silica gel desiccant that changes from blue to pink when the desiccant is saturated and in need of regeneration. I also keep the absolute *minimum* amount of fuel in the tank + some for emergency. To keep mold/fungi spores from entering the tank Im planning to add a 1,0uM (gas) filter to the vent line ....maybe a 0,2uM bacterial blocking filter to prevent bacterial aspiration during tank drawdown, etc. .... not perfect but should 'retard' the inevitable bio-population (the same filter retention I have on my potable water tank vents). I also actively polish my fuel and routinely mechanically clean/scrub the tank walls about every 2-3 years or whenever I can feel a bio-slime forming on the tank walls. I dont have **any** fuel/filter problems. I usually 'test' any fuel for a haze before it goes into the tank (a sign of degradation/water saturation) by holding the fuel in a clear glass between my eyeball and a stong white light ... if cloudy I go somewhere else for my fuel. I usually avoid marinas and usually go to high turnover fuel depots (the ones that cater to 'watermen' or commercial fishing fleets) .... or jug it in from a truck stop. Been deeply involved in 'filtration engineering' for about 35 years.
Oil is either distilled or cracked at high temperature; the high heat of cracking/distilling/formation and recovery renders the fuel 'bone dry'. Dry fuel picks up moisture from the ambient atmosphere by absorbtion/adsorbtion ... a physical/chemical equilibrium. If you are getting condensation in the fuel it means that the fuel is already 'saturated' with water vapor and not all off this is 'free' water but includes water as an emulsion, ad/absorbed water as well as free water. Tanks by themselves do not promote 'condensation'; evidence of condensation only shows that the fuel is already saturated with water. Ways to prevent 'condensation': 1. NO fuel in the tank or a minimum amount, 2. a vacuum/pressure rated tank .... with a valve on the vent that's closed when not drawing down fuel. 3. a desiccant chamber (but that will soon also absorb oil vapor also .... the heat regeneration process will 'coke' the oil into the surface area of the desiccant) - tricky. I use a desiccant chamber of activated alumina on the vent, ...... the regeneration of the desiccant is difficult for a 'consumer'. This desiccant chamber is clear plastic 'cylinder' and has a 'trim' section/layer of dyed silica gel desiccant that changes from blue to pink when the desiccant is saturated and in need of regeneration. I also keep the absolute *minimum* amount of fuel in the tank + some for emergency. To keep mold/fungi spores from entering the tank Im planning to add a 1,0uM (gas) filter to the vent line ....maybe a 0,2uM bacterial blocking filter to prevent bacterial aspiration during tank drawdown, etc. .... not perfect but should 'retard' the inevitable bio-population (the same filter retention I have on my potable water tank vents). I also actively polish my fuel and routinely mechanically clean/scrub the tank walls about every 2-3 years or whenever I can feel a bio-slime forming on the tank walls. I dont have **any** fuel/filter problems. I usually 'test' any fuel for a haze before it goes into the tank (a sign of degradation/water saturation) by holding the fuel in a clear glass between my eyeball and a stong white light ... if cloudy I go somewhere else for my fuel. I usually avoid marinas and usually go to high turnover fuel depots (the ones that cater to 'watermen' or commercial fishing fleets) .... or jug it in from a truck stop. Been deeply involved in 'filtration engineering' for about 35 years.
Metal tube vent??
Condensation forms on cold surfaces..well cooler surfaces. If you had a vertical section of metal tubing on your vent tube the condensation would form on this section of tubing and gravity fall back out the vent opening. I also don't buy that water in diesel is a one way trip. More like equilibrium. Diesel fuel will hold X amount of water at a given temperature. The water on the surface of the fuel can evaporate back into the air and move out of the tank. Especially when the tank is warmer and moister than the outside air. But that said in my experience with a 1/4 full tank over 3 1/2 years water condensation isn't a problem. Tank placement may be a factor as mine is under the cockpit and not directly against the hull. Being near the engine the tank seems to warm up some if I motor very long.
Condensation forms on cold surfaces..well cooler surfaces. If you had a vertical section of metal tubing on your vent tube the condensation would form on this section of tubing and gravity fall back out the vent opening. I also don't buy that water in diesel is a one way trip. More like equilibrium. Diesel fuel will hold X amount of water at a given temperature. The water on the surface of the fuel can evaporate back into the air and move out of the tank. Especially when the tank is warmer and moister than the outside air. But that said in my experience with a 1/4 full tank over 3 1/2 years water condensation isn't a problem. Tank placement may be a factor as mine is under the cockpit and not directly against the hull. Being near the engine the tank seems to warm up some if I motor very long.
As a practical matter
don't forget as we go through this highly esoteric discussion, those huge oil storage tanks we drive by at the refineries and bulk storage facilites in which the fuel we all use can sit for weeks or longer all have water bottoms intentionally maintained by the facility for various reasons.
don't forget as we go through this highly esoteric discussion, those huge oil storage tanks we drive by at the refineries and bulk storage facilites in which the fuel we all use can sit for weeks or longer all have water bottoms intentionally maintained by the facility for various reasons.
analogy to car fuel tanks might work if
you could park your car on the water. Then you would get the correct temperature difference.
you could park your car on the water. Then you would get the correct temperature difference.
silica gel could work!
Just pour it in your engine and let it do it thing? Just kidding! That is what your water separator is for. To hold the silica gel. Everyone know that.
Just pour it in your engine and let it do it thing? Just kidding! That is what your water separator is for. To hold the silica gel. Everyone know that.
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