Diesel Tank Clean

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nausier

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Can anyone recomend a way to clean out water and dirt from my diesel tank? Condensation seems to be creating a problem.
 
No easy way to do it thoroughly apart from remove and steam clean. No matter how much you try there always seems crud hidden. Took mine out and after steam cleaning found small pin holes in base. welded new base on and is now fine. Best to find out that way than miles out to sea.
Pete
 
Thanks Pete,

A friend told me that you can buy a machine to do the job for you. Apparantly circulates the diesel and separates the water and dirt. Have you heard of this and how reliable can it be? Sounds expensive!

I am not sure if i have the know how to disconnect the tank and clean it out fresh. Lifes a leaning curve i guess!!
 
Boatone (a forumite on Mobo and Thames forums here) built one with a plank of wood, on which was mounted a pump and replaceable filter, with tubing to circulate the diesel.
 
I guess it depends how thoroughly you do it, and if you have any baffles in the tank that would prevent you getting the tubing into all the nooks and crannies.
 
A friend of mine just told me that he used diesel biocide to kill off a bacteria growth in the tank which seemed to work a treat. Any experience with that?

Just looking it up now.
 
Biocide will kill the bugs, but if you've had a lot of growth, then that growth will still be in the tank, and potentially clog your filters

Some swear by products like Soltron which claim to break down the bugs so they can pass through the filters without clogging the filter.
 
My local engineer has a mobile "fuel polishing" rig to clean fuel systems. I don't know how effective it is at getting rid of accumulated tank sludge though.

From bitter experience I can say that if your tank has a baffle in it then a single access plate won't be enough! I had to cut another opening to remove a bucketfull of 25 yrs worth of accumulation. Yeuch /forums/images/graemlins/frown.gif
 
Just found agriemach, they do a racor biocide and i have used racor filters that do an exceptional job, so i am assuming if that if the biocide lives upto the quality of the filters it should help if i get round to a tank clean? Although saying that, i wont be moving until a tank clean!!
 
I have permanantly installed in my boat the means to circulate the diesel from the main tank through a combined water trap and fuel filter. The system consists of a motor vehicle diesel electric lift pump. The inlet is connected via a flexible rubber hose to a copper pipe that is fed down the level dip stick tube which has a bore of 1" this pipe sucks the fuel from the bottom of the tank. The outlet from the pump returns via an other flexible hose into the top of the dip stick tube. This means that any water or loose particles are cycled through the filter and water trap. This setup can be run for hours if required. the pump was supplied by LSUK Transfer Fuel Pump Part No. 0-296-12 120 litre per hour Suction 0.2 bar, presure 0.15 bar.
 
P.S. Because it is intended for a road vehicle where the engine and tank are basically at the same level it does not need to lift the fuel trough a large vertical height. In a boat it is important to locate the pump so that end of the pick up pipe is no more than 6 ft below the pump and or the outlet is now more than 4 ft 6in above the pump, otherwise there will be no flow.
 
I am not over confident with installing myself. Looking at a write up on a portable diesel cleaning system, i can keep it on the boat, empty or re-circulate the tank but it did say keeping the tank full when not in use will prevent water buid up. Although this will not stop the bacteria. The biocide can do that and the system can clean it out once in a while.
 
To be honest I was not hving a problem with dirty fuel or diesel bug. I had previously had a problem with micro air leaks geting into the leakoff return line which was under a partial vacuum when the engine was not running,because by main tank is in the keel under the engine. I solved the problem by replacing the leaking pipes. I read in PBO that if I had a day tank set above the engine this would ensure that entire system would be permanantly under positive pressure, thus ensuring this could not reoccur. The pickup pipe in my main tank is 3 inches off the bottom of the tank so it was possible for a couple of inches of water to collect in the bottom of the tank which would be an ideal breeding ground for diesel bugs. So the above installation was a precaution to reduce this possibility.
 
The installation was pretty straight forward. The pump runs off 12volt DC and was simply supplied via a spare fuse off my main fuse board via a switch. The pump pipe fittings are 8mm so are fitted with 8mm diesel proof hose with jubilee clips. The only part to be carefull about as previously mensioned is the vertical position of the pump relative to the bottom of the tank, and the outlet to the top of the tank. The pump cost approx £50 to £60, the pipes cost about £20. The pump was mounted via a couple of bolts through it's flange onto a convenient existing battery support bracket. out of the way but accessable. The pump will self bleed. When it is started up it goes 40 to the dozen until it has sucked up the fuel then it settles down to a steady tick tick which can be heard so you can monitor the progress by sound.
 
sir, you dont say how much of a problem dirt and water is causing you. If it is not catastrophic .. you might consider hoovering around the bottom of the tank with a hand suction pump (access via fuel gauge sender) . you have the choice of throwing it away or filtering and returning. Followed by an additive to your fuel to help its condition and then keep a good watch on you filters. If necessary upgrade them to easier to change units like RACOR or similar. as prev said if your tank has baffles then to do a 100% job you need to access each compartment individually as much crud can accumulate behind the baffles. if you were able to do a good in situ clean out then occasionally circulate/ filter then that would be a good result. I speak as someone who has twice had simultaneous twin engine failure due to fuel contamination at sea.
 
I sourced a small 12v inline Rule pump from the chandlers (which is stated as diesel compatible) and attached a lenght of flexible tube followed by bendable copper tube (domestic gas piping), fed the tubing down the filler cap to the base of the tank and directed the outlet from the pump into a clear 10 gallon vessel (tank was fairly empty!). By bending the copper tube around a bit I was able to reach most of the bottom of the tank (un-baffled admittedly). I simply drew up diesel until it ran clean, allowed the crud to settle out of the extracted diesel and then pumped most back into the tank. This might not have got rid of every last bit of water and debris but it certainly got a fair bit out; a repeat performance a few months later gave only clean diesel.
 
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