Fuel Polishing-Worth it?

[Surely Bassey]

I have a single 92 gallon tank on a 13 year old Grady 228.
I have never tried to clean out the fuel tank. Is it worth it? Advisable?
Or let sleeping dogs lie?

 

[wrxhoon]

It's a good idea to clean it but not easy to remove the tank. I tried to lift mine out ( same size as yours , same boat) , it wouldn't fit . I ended up taking the fuel sender out and gained excess from there to clean it.

 

[seasick]

I have a single 92 gallon tank on a 13 year old Grady 228.
I have never tried to clean out the fuel tank. Is it worth it? Advisable?
Or let sleeping dogs lie?

If you have been using ethanol for a while and don't have problems with clogged filters, I would leave it alone. The ethanol kind of cleans out the tank. If you haven't used ethanol but will be, cleaning may be a good idea.
All that aside, aluminum tanks can develop pin holes over time. No fuel polishing is going to help and could worsen the situation.
let those sleeping dogs lie as you say.
Woof

 

[siple]

I do not know about fuel polishing but I can speak to water in the fuel. Last year we went boating with my newly acquired Grady Tournament 19. My boat had not been run for many years and had a almost full tank of gas. I change filter drained as much fuel as I thought necessary and diluted the rest with new fuel. We trailered the boat to our vaca destination dumped overboard and put it in the slip. All went well at that point.. The next day we went fishing and that is when the problems started. We ran the boat in the no wake area and when we got to the point when we could throttle up the boat it quit running. Luckily we were able to to drain the fuel filter and limp back to the slip. After a week of running and draining water from the fuel separator filter every day I thought the problem was solved. We trailered the boat home and I decided to investigate the water in the fuel situation. I took the cover off the fuel sender removed same and proceeded to drain the tank filtering the fuel and inspecting the bottom of the tank.. When all was said and done I drained the entire contents of the tank and ended up with about a gallon of water. My boat is a '87 and I am sure it was never drained since it was new. So in conclusion, if you are able to drain and clean the fuel by polishing or whatever it is worth it. Knowing the tank is clean eliminates a fuel problem if engine is not running properly. Remember Murphy's Law rules!!!

 

[seasick]

I do not know about fuel polishing but I can speak to water in the fuel. Last year we went boating with my newly acquired Grady Tournament 19. My boat had not been run for many years and had a almost full tank of gas. I change filter drained as much fuel as I thought necessary and diluted the rest with new fuel. We trailered the boat to our vaca destination dumped overboard and put it in the slip. All went well at that point.. The next day we went fishing and that is when the problems started. We ran the boat in the no wake area and when we got to the point when we could throttle up the boat it quit running. Luckily we were able to to drain the fuel filter and limp back to the slip. After a week of running and draining water from the fuel separator filter every day I thought the problem was solved. We trailered the boat home and I decided to investigate the water in the fuel situation. I took the cover off the fuel sender removed same and proceeded to drain the tank filtering the fuel and inspecting the bottom of the tank.. When all was said and done I drained the entire contents of the tank and ended up with about a gallon of water. My boat is a '87 and I am sure it was never drained since it was new. So in conclusion, if you are able to drain and clean the fuel by polishing or whatever it is worth it. Knowing the tank is clean eliminates a fuel problem if engine is not running properly. Remember Murphy's Law rules!!!

Just curious; How often has the o-ring on the fuel fill cap been replaced?

It should not be necessary to regularly drain the bottom of the tank of water. E10 gas will absorb up to approximately 1/2% water by volume. So if you had a 50 gallon tank, filled it up and dumped a quart of water in the tank, there would be no water on the bottom. So every time you add new fresh ethanol gas, potentially more water can be absorbed. Assuming that water is not getting into the tank (hence the question about the o-ring) from rain or washing and assuming that you gas is relatively clean, water shouldn't accumulate in the tank.
The effects of condensation and water vapor are exaggerated and except in climates with high humidity and large temperature swings, the amount of condensation is minimal volume wise.

 

[siple]

I agree the water in my tank was due to several factors not just condensation.. The fuel sending unit needed to be replaced. When I replaced it all screws gaskets etc were replaced to insure a water tight seal. The fuel fill was checked for proper seal and the o-ring replaced. I did notice that the fill cap is tethered by a cable and if not installed properly after fueling can cause water intrusion. The last factor has to do with living in the Northeast where we use the boat a few months a year and it sits the rest of the time. Now, do you store your boat with a full tank of gas that has been treated or???This could be the biggest factor...

 

[seasick]

I agree the water in my tank was due to several factors not just condensation.. The fuel sending unit needed to be replaced. When I replaced it all screws gaskets etc were replaced to insure a water tight seal. The fuel fill was checked for proper seal and the o-ring replaced. I did notice that the fill cap is tethered by a cable and if not installed properly after fueling can cause water intrusion. The last factor has to do with living in the Northeast where we use the boat a few months a year and it sits the rest of the time. Now, do you store your boat with a full tank of gas that has been treated or???This could be the biggest factor...

I have my boat in the northeast also. I store the boat with less than a 1/4 tank of gas with Stabil for the winter. I do not believe that storing with a full tank is necessary or wise. I have stored it that way for 11 years without issue. I also left the fuel fill off for a week by mistake. During that week it rained like heck twice and I was so concerned when I found out, I pulled the sender and pumped out a gallon from the bottom of the tank. Not a drop of water. Did water get in? Most likely but in my case only the actual rain drops get in. On some hulls, water drains around the fill and those boats are mure more prone to water in the tank when the o-ring goes bad or falls off which happens more often than you would think. When should you replace it? When it no longer stretches when pulled or when it is dried out and/or cracked. In general, theyt last many years.
My reasons for storing with a small amount of gas? Well, in the spring assuming the motor starts, I run to burn off any fogging residue and other gunk. Then I replace the filters and plugs and add fresh fuel ( no stabilizer but I do use Ring Free) There is no substitute for fresh gas. Assuming it is fresh (and has ethanol) it will help absorb any residual moisture. The second reason that I store with almost an empty tank is that should the motor not start in the spring and it turns out that the gas is bad, I have a lot less gas to get rid of and getting rid of gas legally and safely can be pretty expensive by the gallon.
One other tip: If you gas up at a fuel dock that sells most of it's gas in the warm months, don't rush to be the first to buy gas in the spring. If there isn't a lot of turnover of the gas in the winter, you have a better chance of not getting bad gas after the old stuff has been used by others and new gas delivered.

 

[seasick]

I would like to add that my comments on fuel polishing apply to gasoline engines. Diesel is a different story altogether.