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Fuel tank problems

7K views 18 replies 12 participants last post by  camaraderie 
#1 ·
I have been experiencing a bug/water problem in my fuel tank. To late I started using a biocide. Now I have dead bugs in my tank which continually fill the bowl in my Racor unit. The access into the fuel tank is only about the size of a silver dollar. I know I can have my tank cleaned and the fuel filtered but this requires that a larger access be installed. I do not want to go to this expense unless it is the only option.

What I want to know is if anyone knows of a way that I can get my tank reasonably clean with the existing small access hole?
 
#2 ·
When you say bugs do you mean fungus which loves diesel fuel particularly in warm climates? If it is the latter, the fungus grows on whatever the fuel touches including the air space above the fuel on the sides and top of the tank. You can kill it with biocide but the latex-like layer remains and it continues to break-up (because it''s dead) and recontaminate the fuel and plug your filter. The only recourse is to install a gasketed top access flange/door that will allow you to get your arm and/or a brush in and give the inside a good cleaning. Perhaps the nozzle of a high pressure sprayer could be inserted instead but remember the top and upper part of the tank must be hit as well. There are some industrial spin-type spray nozzles for tank cleaning that might do the trick too (Spraying Systems, Sprayco). The problem with spray down is keeping the wash down water out of the fuel (disconnect and plug) and then complete drain/pump-out and dry. We went the clean-out door route on a Westwind Vagabond 42. The moral of the story - use biocide/fuel conditioner in diesel - always!
 
#4 ·
AHOY fuel problem victims: There IS a solution...and surprise, it''s NOT an algeacide. What actually happens with an algecide (it KILLS existing algae) is your skeletin''s all slosh around offshore in ANY kinda waves...and work on clogging your filters! PERIOD. I use a product called Deezol.. which ELIMINIATES algae particles AND the water which enables new algae to grow by the way. OH...my fuel is SIX YEARS old since last fuel up..and is as golden as the day I put it in. My filters last THREE times longer than they used to before I started using this stuff. I buy it by the CASE now and all my boating friends are addicted! 1oz per 10 gal of fuel unless ya have a really BAD problem..then ya treat 1oz per 5 gal of fuel..it comes in quarts.. plastic no less. NEAT stuff.
 
#5 ·
Well I am having the same problem. Killed all the algae and now the floating crap clogs everything up in 10 minutes from the pickup to the raycors.
The tank is a 200 Gallon one piece fiberglass WITH BAFFLES that come from the top of the tank to about 1" from the bottom of the tank across its lenght. While there is a nice access hatch on the front of the tank you can only wash the first compartment out, the other 4 behind it are not accessible for scrubbing. I been there done that. Sucked all fuel out through a raycor with an external waterpuppy into drums, filled the tank with tons of detergent and water, scrubbed the first compartment and tried to slosh it around as much as I could but the damned tank is still a mess and I can't get out of the harbour without having to blow back through the pickup at the tank and changing the raycors. I am at the end of my rope. I am all open for suggestions.
 
#6 ·
tank problem

The fastest and easiet way to handle your problem would probably be to hire a fuel polisher to come out and polish the fuel. It would require having a second access port into the tank, but this is generally not too big of an issue requiring a hole saw and vaccum. Generally a 2 or 3 inch hole would do it, then screw a port over the hole.
At least then you are in a known good state and the racor should handle it from there.
After that point always use a good fuel conditioner.
If the problem continues, you can install your own polishing system with just another racor, a 12 volt fuel pump, hose, and a couple of Ts. Let the polishing system run while you are just hanging out on the boat.
Good luck with it.
 
#7 ·
Of course, you can also let the fuel polishing system run while you're under sail... ;) Just don't let it run the batteries down too far.
 
#9 ·
If there is access to the tank, even if it is small, you can pump out the tank using a small copper pipe attached to the pump used to change the engine oil. If completely empty you add some aceton to the tank and pump out again, repeat if the sludge is very dark after the first aceton wash. After cleaning fill tank again. The little remains of aceton will just disolve in the diesel fuel and will be combusted without harming the engine.
 
#10 ·
My guess is that Deezol is just an alcohol-based additive that emulsifies the water and brings it into solution—getting rid of the water/diesel barrier that is necessary for the growth of algae. Using too much of it might be bad for the rubber and plastic parts in the fuel system... Might want to check that before you go overboard with using the product too much.
 
#11 ·
It sounds like you are at the end of your rope (read "line").

You need to treat with biocide on a full tank of fuel (i.e. top it off) and install a polishing system. I am partial to filters installed in the vacuum side of the system and filters that match what you currently are using (i.e. RACOR). Once you complete the installation, rotate you fuel through the filter. Install vacuum gauges on your filters, this way you can monitor the rate at which you are clogging the filters and you'll know when the filter has served its useful life. You will soon see at drastic change in the rate at which the polishing filter is getting clogged. I would then polish the fuel on a regular basis.

When you design the polishing system try to make it versatile. For example, use it to polish while underway and/or to pre-filter en route to your primary. Make sure you use the proper pump, i.e. for use with diesel fuel. Install a suction tube that reaches all the way down to the bottom of your tank if at all possible i.e. "stripping line".

I have been in your shoes before, but, with 4,000 gal of contaminated fuel on 8,500 K gal capacity tanks. I was plugging my polishing filters every 250 or so gal while burning 120 gal an hour underway; by the time I refueled we had no more problems... never opened the tanks.

There is hope....
 
#12 ·
georgellop said:
It sounds like you are at the end of your rope (read "line").

You need to treat with biocide on a full tank of fuel (i.e. top it off) and install a polishing system. I am partial to filters installed in the vacuum side of the system and filters that match what you currently are using (i.e. RACOR). Once you complete the installation, rotate you fuel through the filter. Install vacuum gauges on your filters, this way you can monitor the rate at which you are clogging the filters and you'll know when the filter has served its useful life. You will soon see at drastic change in the rate at which the polishing filter is getting clogged. I would then polish the fuel on a regular basis.
I don't have this problem, but I have a plan to avoid it...

We are planning to circumnavigate in '09 and I have starting to buy stuff to improve the boat's systems. Currently, I have a Westerbeke W-52 with two steel keel tanks of 50 gallons each hooked to a manifold that allows delivery and return from either tank, or conversely, delivery from one and return to the other.

I also have a 40 gallon stainless steel one-time holding tank directly under the engine. I plan on removing the engine for a top overhaul, to paint the bilges, to install bigger batteries and to weld in cages for them (steel boat), and to put in a thrust bearing for an Aqua Drive coupler installation mated with a VariProp four-blade feathering prop: http://www.aquadrive.net/ad_features.html

Now here's the pertinent bit: I want to rehab the SS holding tank to a "day tank" for diesel that will at all times hold 40 gallons of pristine diesel. This means (beyond cutting inspection/cleaning ports and changing the hoses to fuel fills and vents) that I have an expanded manifold for the other two tanks to return fuel to the "pristine tank" via a polisher/filter.

I bought this yesterday at the Toronto Boat Show: http://www.ktisystems.com/filter_boss.html

It seems to meet my requirements for polishing, filtering under way, and a method whereby I can still keep the engine going while I keep motoring. There is also an alarm that goes off at a vacuum preset, i.e. if a rapidly clogging filter is about to cease passing fuel=time to switch the ballcocks to "reserve side".

The logic (and the justification for the $1,000 cost) is that a) diesel quality and cleanliness can only be expected to a certain degree in many places, and a Baja filter at the fill can do only so much; b) with the best will in the world, humid and/or stormy waters have the potential to let water into the fuel, and c) the WORST time to find out you have gritty/cruddy fuel is in rough, nasty seas on a lee shore with a shredded main. It's heinous outside, the shore/reef is near, and you have to power off. But the waves are swirling the tank contents into some sort of ur-soup. The engine misses...and stops.

Bang...your boat (and maybe the crew) are dead. For want of a filter, the ship was lost.

The AquaDrive and the beefy prop (that gives me a knot when sailing) and the uber-filter (which can be an auxiliary lift pump if needed or can quietly polish while on shore power) seem reasonable expenses when I consider the alternatives.
 
#13 ·
Valiente:
" I also have a 40 gallon stainless steel one-time holding tank directly under the engine."
If you convert this to fuel...you will be relying on an electric lift pump for your fuel supply integrity. Not a good idea. Clean fuel don't help when it stays in the tank! Let gravity do the work.
 
#14 ·
I seem to remember that stainless steel is considered unacceptable for diesel fuel, something about the sulphur in the fuel attacking the stainless and especially the welds, leading to massive pinholing problems.

You might want to look into that before even thinking about converting a stainless tank. Although new rules went into effect in the US to require low-sulphur diesel this year, that's far from global. Possibly the ss tank would be OK if properly coated with an epoxy liner.
 
#16 ·
Valiente, .... I think it is a top priority to ensure yourself of clean diesel. I don't ever assume that I am getting clean fuel. I have been served contaminated fuel from one of the highest volume dealers right here in Lauderdale. For the benefit of other readers, it doesn't have be a sophisticated system . It could just be a pump and a filter. The important thing is to know that you are feeding your engine clean fuel.

As far as using the bilge tank to feed the engine: check out the manufacturer's specs on the max head at which the engine's lift pump will work. i.e. distance from the tank bottom to the lift pump on the engine.

Alternatively, if the lift pump on the engine doesn't work you can relabel the tanks, make the keel tank a storage tank and one of the other tanks the day tank. You will have to make sure your day tank is full when you go to the pump. If you have less than 50 gal left on board, you will have to stop bunkering for a time period to use your onboard transfer pump to filter the fuel into the day tank. Gravity feeding the engine is by far the best option. Adding an electric lift pump is adding a new weak link to the system and increasing your expense in equipment and spares. Make sure your return is plumb to the day tank.

Sailboat owners, as a group, dislike engines. Yet, they spend considerable time worrying about unreliability and dealing with their breakdowns. This in turn only compounds their frustration and hate for the engine. Because of the small consumption of fuel by the small diesels we run into the problem of contamination of the fuel while in our tanks. If you start out with a good running engine it only takes clean air, clean fuel, proper cooling and lubrication to keep it that way.

Regards,....
 
#17 · (Edited)
FilterBoss

Valiente - I also picked up a FilterBoss system after seeing it at the Newport Boat Show last fall. I've dealt with the sludge in the tanks stopping me dead so I wanted to never let that happen again. Sounds like my NC had a similar setup to yours with a pair of 60 gallon tanks, but since mine came with an extra set of output lines from deeper in the tanks switchable to a manual 'Dirt Out' pump I decided to go all out and create a total on-board polishing system as my big project this winter. Besides the 'normal running' switchable tanks and alarmed filters I'll be able to polish L to R, R to L, L to L, or R to R by flipping a few levers. Andy the owner is a sailor and a great guy to deal with. After a few phone conversations with him I was ready to fork over a few hundred to his company for the manifold systems I 'thought' I would need - but no - he whipped up and faxed me a schematic that will do everything I wanted with a few valves saving me big bucks. His wife is the one who answers the phone also - a real high tech 'Mom and Pop' operation.
 
#18 ·
Not sure if I understand Cam's dislike of an electric pump for diesel - presumably it is because of another failure point assuming you can start the motor without power. But the Beta (Kubota) owner recently said these motors only have a one foot lift pump and any further requires an electric pump. That isn't much from the bottom of a tank and would presumably mean that a tank couldn't be placed in the bilge. Gravity feed has disadvantages in weight distribution, except that would be minor for a day tank. Do other motors have similarly limited lift pumps which could be a cause of failure if the tank levels are low?
 
#19 ·
Chris...that is exactly why I don't like the idea of the tank underneath the engine. You need a tank that is either level with or above the engine to allow gravity with a bit of help from the on-engine mechanical lift pump to keep you running.
Putting an electric pump in line on a BELOW engine level tank makes that pump a critical unit that cannot be bypassed if it fails. Failure can come from the pump itself or an electrical system failure. This is common on most diesel on-engine lift pumps so you rarely see an original equipment solution with the tank below the engine.
Electric pumps are often used in line to help prime the system when changing fuel filters and to provide a backup to on-engine lift pumps but should not be a critical part of the fuel flow system.
 
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