cleaning fuel tank

sailaway78 · Mar 16, 2009

Fuel tank

Lots of opinions on this subject, and I'm sure you will get lots of different answers/opinions. I belong to the "if it ain't broke, don't fix it " school. If you have never had a problem, and have no indication of a problem arising, I would leave it alone. A lot of the fuel problems most encounter depend more on how much fuel you burn, and where you get it. If you burn a reasonable amount of fuel, and get it from someplace that sells a lot of fuel, much less chance of a fuel problem than if a full tank lasts you two or three seasons. Also, I don't know how much you use your engine, but I would never, ever go two years on fuel filters. Mine get changed ever spring regardless. Never have a problem, but fuel filters are cheap. Changing filters and cleaning the cannisters can give you an indication of a problem, before you have a problem. I also carry two sets of spare filters on board.

Don S/V ILLusion · Mar 16, 2009

Dave
If you don't want to filter the fuel which may be unnecessary, I suggest an easy way to check the tank bottom for water. Assuming you have the means of pumping lube oil from the dipstick of you engine, use the same method through the fuel gauge by inserting the tube to the tank bottom and drawing from there. Any water in the tank will be obvious.

It takes 15 minutes and seems counter-intuitive NOT to check.

This obviously won't remove crud from the tank walls any more than filtering but if free of water, it's unlikely there would be much.

I've done this every spring and usually never find any water but one year, I removed approx 2 pints which for some reason collected which I would otherwise have never found until it was too late.

Chuckbear · Mar 16, 2009

drm said:
I own a 2002 Hunter 356 and keep on Lake Superior. I have never had the diesel fuel polished or the tank cleaned. I also have never had any trouble with the boat clogging. Two years ago I change both fuel filters as a preventative maintenance procedure.

Do I or should I clean or polish the fuel tank?

If yes, how often should this be performed?

Finally, do you have tips or instructions on how to clean the tank?

Thanks

Dave

Dave, I have a firm rule, "if it ain't broke don't fix it". Now having said that regular maintenance is a real good idea in a boat. First I would like to add that two years on a filter is not the norm. Depending on how much you use the boat, filters should be changed every 100 to 200 hours again depending on how clean your fuel is. A filter can be fine one minute and the next you have engine shut down. If you don't use the boat that much during the season then the filters should be changed at the beginning of each season. This has less to do with how the engine is running today and more to do with problems down the road with injectors and very expensive injector pumps. A good recommendation is to also have the tanks cleaned every 5 years, again as preventive maintenance. It is not as critical for folks that spend most of the time sailing around the buoys and weekend trips where Sea Tow is close by, but those of us that spend long periods of time cruising in remote areas, this is just good practice. Many times fuel problems do not manifest themselves until you get caught out in weather and the fuel in the tank gets agitated from the boat rolling around and pounding into chop. All of a sudden the engine shuts down just when you need it the most. A diesel engine should NEVER be run without proper filters.

BaySailerBill · Mar 16, 2009

This is a very timely topic. I'm preparing to begin checking out my 1984 C-27 that I purchased at the end of last season. I have no idea if the previous owner ever checked the fuel tank. Should I clean it out just to be safe? If So, what is the best way to clean-out a diesel tank?

Thanks
BILL

Chuckbear · Mar 16, 2009

To clean the tank you are going to need some equipment that is not available cheaply and it might be cheaper to have someone come in and clean it. If access to the tank is good and you can get inside, empty the tank and clean out with rags and solvents. But that is usually not practical or possible. To clean it a strong circulating pump is needed and the ability to pump the fuel out of one end of the tank while pumping it back in under high pressure to stir things up, all the while filtering what is going through the pump. The correct equipment is important to get it right so this is why it might be better to have a professional do the job. The process is continued until the filters in the pumping system stay clean. Even with this process it is not possible to get 100% but it will be close. Chuck

Vision36 · Mar 16, 2009

I have a 95 Hunter Vision 36 that is in the middle of correcting a fuel problem. I do not use the motor much (only about 5 minutes out the harbor to put sails up). The fuel in the tank was 2 years old. Although i put in a fungicide, the tank still gunked up. The remedy to my problem is pulling the tank (which i have done), cutting 2 holes in the top 4" x 6" (which i have done), cleaning it out completely and wiping dry. I got out about a quart of "gunk" that was floating around in the fuel. Now I have installed a plate covering the hole with a gasket and secured with self tapping screws. The tank is now ready to be re-installed and should be good to go for a long time to come.

Stu Jackson · Mar 16, 2009

One link with two stories for you

try this and scroll down to tanks, two articles: http://www.c34.org/wiki/index.php?title=Fuel

Th there's the other side of the coin: http://c34.org/bbs/index.php/topic,2767.0.html

I agree with the "if it ain't broke" approach also. People tend to obsess with this issue. You have to determine if your fuel supply is contaminated, too, beyond the "everything falls to the bottom" concerns.

Ours is 22 years old, same tank, no cleaning, no polishing, no evidence of gunk, or leaks. It could be there, hiding deliberately on the bottom of the tank :cussing:, but it hasn't affected me to the extent I worry about it or feel it's necessary, since the filters are fine when I check them.

Your boat is relatively new, also, compared to many.

Your boat, your choice. Good luck.

s sauer · Mar 16, 2009

Check the fuel level and empty the tank by pumping out thru the fuel line at the filter.
When you start to get dirt or water inthe diesel, pump the remaining crud into plastic gallon jug(s) for disposal. Give away the old fuel to someone who has an oil furnace.
Google Seafit and buy an access port; drill a pilot hole and cut the 6" hole near the center where you can reach most of the tank. Use clean rags and alcohol to clean out the crud, fuel and shavings from cutting the acess port. I used a fly swatter handle with a rag to get the other end of the tank. Make sure you get the top surfaces the pick-up tube and fuel gauge float with alcohol as well. Do not use paper towels as they leave lint to clog your new fuel filters. Replace the filters and the flexible rubber/nylon fuel lines from tank to filter and the return line from the injectors to the tank. Re-fill with five gallons from a very active truck stop and bleed the system. You will spend much less $140 or so on the access port than you'd spend on one fuel polishing and hand cleaning will be more complete since you can see what you're doing.

petersea · Mar 16, 2009

OK another vote for "if it ain't broke don't fix it ". Unless you have some problem 7 years is not a long enough time to think about cleaning a tank. It does very little good to polish the fuel unless you clean the tank as well. You did not mention if you have treated your fuel with a a fuel treatment of some sort and did not mention how much you use your fuel. One tank a year or are you still using the original fuel ?? To my mind if your filters are clean your fuel and tank is most likely also clean. Just seams to me you are making a problem that does not exist. But give us some more info on age of fuel or amount of fuel you use. I like Don's idea of dipping our tank and checking for water. As I recall years ago when I worked in a gas station after school we used to dip the tanks regularly with a litmus paper (??) to test for water. I also got to think your boat has a water separator/fuel filter, check it regularly also and maybe I'm not reading correctly but if you have a 2002 boat (are you the original owner) and only changed your filter two years ago then you went five years on the original filters ?? What did they look like when you changed them ?? Respectfully suggest change both fuel filter every two years minimum. Bottom line is leave it alone IMHO.

chuckwayne · Mar 16, 2009

After real fuel crud problems with my old Hunter 29.5 (second owner) I built a polisher for Escape. We used a 12v transfer pump and a 200 series racor, built into a 5 gallon paint pail. Before the rear cabin bedding is installed in the spring, we polish the fuel in the tank. Open the escape hatch and remove the fuel guage sender in the top of the tank. place your pickup tube in the tank, and the outlet tube through the hatch, aft to the fuel filler, and run it. We used a clear piece of tubing in the pickup so you can observe, and you can reverse the hoses in the tank if you want to use the outlet to blow loose stuff in the tank. The 356 tank is supposed to be baffled so adding a cleanout and reaching in isn't practical.

Chuckbear · Mar 17, 2009

chuckwayne said:
After real fuel crud problems with my old Hunter 29.5 (second owner) I built a polisher for Escape. We used a 12v transfer pump and a 200 series racor, built into a 5 gallon paint pail. Before the rear cabin bedding is installed in the spring, we polish the fuel in the tank. Open the escape hatch and remove the fuel guage sender in the top of the tank. place your pickup tube in the tank, and the outlet tube through the hatch, aft to the fuel filler, and run it. We used a clear piece of tubing in the pickup so you can observe, and you can reverse the hoses in the tank if you want to use the outlet to blow loose stuff in the tank. The 356 tank is supposed to be baffled so adding a cleanout and reaching in isn't practical.

These systems work to keep fuel clean but will not actually clean the tank unless you are using a pump that has somewhere around 100 GPH equivalent. Otherwise you won't get enough fuel flowing back into the tank to really stir things up. I generally call these systems a "fuel filter enhancing system" as opposed to fuel polishers. If the tank is clean or cleaned and these systems are used they go a long way to keeping tanks and fuel clean. Chuck

Ron McCoy · Mar 17, 2009

I like Don's solution. Use your oil extractor by attaching the flex hose to a steel rod. Open the tank's top access port (filler hose, whatever is available) and run the vacuum hose around the bottom of the tank. Watch for any gunk as it flows through the clear hose. After a couple of pints and you'll know what's in your tank. I usually find a 1/4 cup of black goo - which isn't much in a 28 gallon tank. When the fuel runs clear - stop, you're done. It's a routine spring-time maintenance job that takes 15 minutes and provides me assurance that a fuel problem is "less likely" to impact our cruising. IMHO: Get it out of the tank before it causes a problem. For those who have never checked their tank - you might be surprised what you find.

BaySailerBill · Mar 17, 2009

After listening to all of your opinions, It looks like I'm going to drain and clean my tank. You know what they say...
When in doubt - Wash it out!