Fule Tank Cleaning

[Fair Well]

Hi all new hear but have been reading forum for last two years. Last March I bought what I call a charity boat she is a 78 ft Hatteras. She had been sitting for about three years with out much TLC. I need some thoughts on cleaning the fuel tanks they are in pretty bad shape. On the way back form FL to take her to her new home in TX I was changing fuel filters every 8 to 16 hours depending on seas. Some have told me to cut holes in top of tanks big enough to get in to clean and pressure wash. sounds good in theory but when you recover the holes how do you grantee they wont leak, Diesel well leak through just about anything. Another Marine out fit in Fl told to put a fuel polishing system on board. Yuck more filters to change not to mention the room they take up. Then someone recommended that I make friends with someone that has a portable fuel polisher fill the tanks up about half way get a 16 gal. keg of BEERgo out in about 3 ft. seas get the fishing poles out turn the polisher on let it do it's work while we fish and drink beer for about 10 hours. Needles to say I like the last idea best don't know if it would work but at least it would be fun!!

[captainwjm]

I was faced with a similiar situation - not a charity boat, but one that had been used as a floating condo for about 5 years. I just ran the boat, and changed filters [Racors] until the change interval decreased to where I was doing it based on hours, not need. Added that Starbrite brand enzyme additive with each fill-up [don't have a clue as to whether it did any good - sort of like that aspirin I take every day, it couldn't hurt]. Anyway, it worked for me. Congratulations on the new vessel!

[rsmith]

I'd bet their pretty well clean by now. Just treat with some biocide and keep on running it.

[saltshaker]

I agree with the above. If you have Detroits, they return a lot of fuel so essentially, you're polishing the fuel as you run. When you started running the boat you loosened up all the crud on the tank walls and baffles. Once that stuff gets stirred up in the fuel, you start to foul the filters. You filter change interval will start to improve. You may want to get a tube down to the bottom of the tank to be certain there isn't any water in there. If you've got water, you have to get rid of it or you'll be getting bugs in the fuel. I f the solids in your filters are gritty or sandy you may want to consider fuel polishing. You may have algae or sand in the tank. Most likely you're just dealing with fuel agglomerations or asphaltene. These are solids that form when the fuel starts to break down. Be careful not to over treat the fuel with additives or you fuel may become corrosive or cloudy. Best thing you can do is run it. Try to avoid refueling until the tanks are pretty low. This way you'll keep adding fresh clean fuel which will help clean the tanks even more.

[Fair Well]

Thanks, I have a friend who works as parts manger at equipment co. He can get me Racors at his cost I ordered two cases. Well try to get tube to bottom of tanks with drill pump to check for water.

[saltshaker]

Thanks, I have a friend who works as parts manger at equipment co. He can get me Racors at his cost I ordered two cases. Well try to get tube to bottom of tanks with drill pump to check for water.

If you have sight gauges, you can pull them and get to the bottom of the tank that way. If not pulling the sending unit will get you there. Should have asked this earlier, but are you using 20 micron filters? You should be using the 20's in the Racors. Also don't change them prematurely. If you have vacuum gauges wait until you start to pull vacuum or the needle is in the red or close to it. A dirty filter will work better than a clean one until it reaches a certain level of saturation.

[Jaxfishgyd]

When we bought our boat back in 2000 I had a fuel polishing company come out and do both of my tanks.... Luckily it took less than 90 mins for both tanks as they were clean...... They put two hoses down each one...one for pressure to stir things up and the other to suck out and clean...
But at least I then knew what I had.......

[Fair Well]

Yes have sight gauges need to pull them anyway to fix the floats they don't work. Yes using 20's I usually don't change until I notice RPM drop unless I know I'm going to get in a tight spot.

[bobk]

When your tanks are say 1/3 or 1/4 full, run one engine from each tank but return both to the same tank to run one tank dry. If you can do this on a bumpy day, you ought to do better scavanging the junk off the bottom. Repeat for the other tank after restarting the fuel starved engine.

Polishing with a pressurized fuel return will work very well IF you can reach the entire bottom of the tank. That might be difficult or impossible with baffeled large tanks. As others have said, as you keep running, your filter life ought to be improving. Don't forget to change the secondarys each time as well.

You may want to put rebuild kits in the Racor's as well. They sludge up and restrict fuel flow at the ball and it's a very cheap repair.

Bobk

[bostonhatteras]

It's easy to get a substantial jump on the tank cleaning process. You can do it yourself now and if you do it once every spring you'll never have fuel problems. First get your oil change/fuel transfer pump. Next take black iron pipe 3/4" and cut to a workable length for your tanks. On the remaining threaded end create a fitting, a hose barb or threaded connector, whichever works best to connect to your oil change pump. Now with this pipe attached to your oil change pump go and vacuum the bottom of each tank. Removing 5 gallons per tank should be enough but you'll know as you begin. If the fuel looks like a strawberry shake then you have a lot of water that is being emulsified into the fuel. Keep vacuuming until this is clear fuel. The best part of doing this is that you can let the fuel settle and reclaim almost all of it. The water will invariably settle to the bottom. Algea doesn't grow in diesel fuel. Algea grows in the micro interface between water and diesel. Eliminate the water and you eliminate one life sustaining component for the algea. Biobor jf is in my opinion the best algea eliminator. Sure you could just continuously swap filters to try to clean the tank but the fuel pick up lines do not go all the way to the bottom of the tank so you'll need a long time and a lot of agitation to get all the fuel. If you let the boat sit still, all the water will settle to the lowest part of the tank and you'll easily get it with my method. The water is the problem, the dirt is too big and is easily removed by the filters. On the filter element algea becomes a slime that coats the filter whereas dirt remains individual little bits that the fuel flows around. Vacuum the tanks and be done with it. But always have at least two filters per engine and per location ( 2 primary and 2 secondary) per engine when you leave the dock.