Fuel Polishing

[earlcarlo]

Has anyone had their fuel tanks polished? After running the boat for about 30 hours the fuel filters got clogged and the service manager at my marina recommended to clean the tanks. I have an 2001 31TE with twin diesels and I don't see how the tanks can get serviced without cutting a hole in the decking. The boat has 2 Racor 900MA as the primary filters. I do not have a pressure gage for them. The elements are 30 micron. The secondary filters, I believe are 2 micron, but I will have to check when I go to the boat to be sure. There are 3 aluminum tanks. The tanks are joined together by a manifold with values at the aft end. The shut-off values are installed at the fuel delivery hose connections to the Racor fuel filters. I have an analog fuel gauge with a toogle switch to test each tank. I'm new to this so if I'm missing any information please let me know I will update this posting. Thanks Earl

[N4QC]

For my tank, I remove the fuel gage sender and gain access that way.

If you give a little more detail as to what your fuel system consists of: filter type and sizes for both primary and secondary filters, any pressure gages, bypass valves etc. perhaps I can give you a little more insight.

By definition: primary filter is the one (s) closet to the tank; secondary filter is the one on the engine...

Have fun,

[Russell]

I have seen them polishing fuel in my marina and they stick hoses into the fuel filler. They pump the fuel through large racor type filters and back into the tanks. When I purchased my Albin it had been sitting for a year and the broker put Algae X into the tank and I changed the racor filters twice and drained the water and crud from the bottom. After that it was fine. If you suspect there is a large amount of water in the tanks do not add a dispersant. Check the racors for water and if there is a lot you might want to go the polishing route. I purchased a T-handle vacuum gauge from this site: http://designatedengineer.com/index.html and periodically check it at cruising speed. I also bought one of their valves for the drain hole so it is easy to drain off any water and black junk. I am not sure what polishing costs but it may be more than a few filters. As you know the fuel is pumped at a higher rate than it is used and the excess returns to the tank. So you are polishing it yourself as you run the boat.

[jleonard]

30 hours is not really all that bad. I have been thru worse several times. Itried polishing (filtering off line) once and it really didn't do much. The best thing you can do is buy a vacuum gage as already suggested and stock up on filters and change when required.
In my current boat (old 40 Albin trawler) I was clogging every 6 to 8 hours on my maiden voyage. I installed a multi stage filtration system going from 30 micron to 10 micron to the on engine filters which are 7 micron.
I now get a fulll season, approx 100 hours, and I still have zero vacuum.
Multi stage is the way to go. No question.
Read about it on www.boatdiesel.com
Jay

[N4QC]

The article by Tony Athens on fuel filtering, at Boatdiesel.com is a must read…

Tom, the designated engineer, is very helpful in selecting gages, fittings and filters…

As Russell and Jleonard have pointed out, filtering, using the boat’s own system may be the way to go. A gage on each racor will enable you to determine the best time to change the filter especially if the racors are loading up with black particles. If there is a dark greenish or pink slime, then the tanks should be polished and cleaned .

If the bottom of the racor housing contains crud which doesn’t drain out when the drain cock is opened, then I’ve used a siphon system (fuel squeeze bulb) to suck out most of the bottom. A turkey baster comes in handy for stirring the crud and suspending the particles in the fuel so as to be ready to be siphoned out. You may have to add fuel back into the racor a couple of times. I’ve reused some of the fuel that I’ve siphoned out, after allowing the crud to settle. Clean fuel in the racor is required at the end of the siphoning process…

In any event make sure that you have spare racor and engine filters aboard and be able (location, tools, storage containers, catch and cleanup materials) to change them…

Best way to have a clean fuel system is to use the boat…

Have fun,

[Yearwood]

We found algae in the Racor two years ago and called a company from Pennsylvania that was working in this area (Annapolis). He came to the boat and said he would have to get at the tank sender. He would not work through the fill line for he stated he would have to recirculate the fuel hitting the sides of the tank and the bottom with a moderate pressure in order to dislodge algae. That meant lifting the after deck (or cutting a hole over the sender). We decided to lift the after deck which on a 28 TE is not that difficult and he said he would return late the next day to clean the tank. After lifting the deck I decided to sample the bottom of the tank and the fuel was clean as a whistle. Canceled the polishing. He said he had plenty of business due to ethanol on gasoline tanks. As best we can determine we asked the marina to replace the Racor element on commissioning, they did so but never cleaned the bowl. All was not lost for our level sender was faulty and I replaced that.