Is there a way to clean out the sediment, vapors, and what ever kind of junk that may be laying on the bottom of the fuel tank without removing the tank from the hold, rather than waiting for it all to mix in a bad storm and shut off the engine, leaving you to drift into a jetty and completely ruining your day? Sue & Larry respond:
Sludge, grime, bacteria, etc. laying in the bottom of your diesel fuel tank, as you well point out, can cause serious problems. Almost every cruiser we know has had to deal with this scenario. It usually rears its ugly head at the most inopportune time. During rough seas, the sediment laying in your tank is stirred up and mixes with your fuel and then makes its way into the fuel line where it clogs your filter in short order. Once your filter clogs your engine is soon starved of fuel and stops. Itís in these rough conditions that you may need to call on your engine the most for assistance in staying off a lee shore or entering a tricky inlet. And it's easy to see how important it is to know that you can rely on your engine.
The short-term fix is to run below, change your filters, and then you'll likely have to bleed some air out of the fuel line. In the long term, youíll want to address the root of the problem, or itíll happen over and over again.
The sediment in the bottom of your tank is likely to be comprised of algae, made up of micro-organisms of bacteria, fungus, and yeast. But you could also have dirt, scale, or even rust down there. To remedy the problem of fuel tank sediment, you need to clean the sludge out of the tank and then remove any suspended particles from the fuel. This is almost impossible to do yourself. Your best bet is to hire a professional fuel tank cleaner. Companies specializing in fuel polishing and tank cleaning will access your tank at its lowest possible point to remove any accumulated water, algae, or general dirt and sediment. Then a filtering process begins. The fuel in your tank is agitated by recirculating your own fuel under high pressure to break loose and suspend any contaminants in the fuel. The fuel is progressively filtered until it is clean.
Depending upon the size of your tank, the whole process will take a couple of hours to about half a day. After youíve cleaned your fuel and tank, there are certain preventative measures you can take to minimize the reoccurrence of sludge.
For more information you might want to read: Diesel Fuel Essentials
, by Tom Wood. Itís archived here at SailNet.