Fuel Polishing

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Senior Member
Oct 6, 2007
The sound of a diesel to a trawler or motor yacht owner is like music to our ears.

But problems can occur with diesel fuel stored in your trawler or motor yacht fuel tanks, affecting those diesels?

It is important to know what diesel fuel is to begin with. Diesel fuel is refined from crude oil. In oil refineries, crude oil is heated, and various hydrocarbon molecules are extracted to create the fuel. Diesel is much heavier than gasoline and evaporates much more slowly. It's often referred to as "fuel oil" because of its consistency. Often forgotten, diesel is an organic matter.

Today as part of our continuing Spring commissioning, I had our trawler, the Patricia Ann, fuel polished. And after 8 years of NO problems I was relieved to find out we were in good shape.

I've already posted about it but you can see photos and read details about it on our Blog, enjoy.

Did you "shock" the system with some treatment or biocide before polishing, or feel the need to do so?
Why did you polish your fuel? Do you have access to your tank bottom?
While the process you describe is the typical fuel cleaning we encounter, there should be one consideration for those planning to do this. It is true that any filtering of old or dirty fuel will indeed help and make an improvement, if you do not begin with a clean tank, you will soon have dirty fuel again. The recommended approach is to remove the fuel and clean it off site, while having the tanks throughly cleaned while empty. When the clean fuel is returned to the clean tank, a regular schedule of polishing by filtering in and out will help maintain not only the fuel but the tank. This more comprehensive cleaning should be a regular scheduled maintenance item about every five year at least. The pumps used to process the fuel should also be capable of really stirring up the tank as it filters through, but even with that, the internal baffles will prevent a really thorough cleaning that you might be trying to accomplish. Chuck
Polishing fuel and not cleaning the tank is like "putting a band-aid on an infected finger".

El Sea/L.C.
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