How do you polish your fuel?

[mike ritenour]

This is a follow up on another post that was talking about keeping fuel clean......

For about $70.00 I went to my local NAPA store and bought the hardware to mate up a 12v diesel fuel pump and a cheap NAPA filter unit. A few bits of plumbing, some battery clips, ten feet of good quality wire, some hose clamps and it was done.

I mounted the "system" on a small piece of starboard and attached a wiring harness for battery power. I made the wiring harness long enough to keep any potential spark hazards at bay.

Think it took me about an hour to assemble the unit and I had a high flow fuel polishing system which easily stores below.

One side benefit is the larger diesel fule NAPA filters are FAR cheaper than my Racor filters while having a MUCH larger area for filtering gunk out of my tank.

To recirc my fuel I've tapped into my primary fuel line, before my Racor fuel filters, to draw fuel through the system and plumbed the return clean fuel line back into the tank.

I wait until my fuel level is fairly low and then run it for a few hours, polishing and repolishing the fuel. Works like a charm and really lengthens the service life of my expensive Racor filter elements.

The unit also doubles as a fuel transfer pump. A few years ago while in a remote Newfoundland area we were able to take on fuel from a large fuel barge using the pump. It was the only way we could have gotten fuel, as their pump had a 6" discharge line.

Sail on!
Rit

[Ed Haley]

Sounds like something that should be aboard all diesel boats. In the long run, it would keep potential fuel sediment problems out of your boat and out of your mind.

How do you stir up the bottom-attached sediment so that you can filter it out of solution? This happens occasionally when the boat hobby-horses around in a seaway but unless the tank is agitated, the sediment remains on the bottom. Just wondering.

[mike ritenour]

Ed,

I had my tank steam cleaned a few years ago and routinely polish my fuel while either underway or at the dock after being underway.

Seems to work as I have almost perfectly clean secondary and primary fuel filters.

Rit.

[Klem]

Having spent a lot of time working on old tanks, a homemade polisher as most people build them only really works on small tanks that start relatively clean. The idea of polishing is to cycle all the fuel through the filters a bunch of times and agitate the tank. Home polishing setups tend to lack the pump flow rate to properly agitate a tank. The setups that I have seen have tended to use cheap, low flow, low pressure 12V pumps. There are certainly pumps out there that are powerful enough but something like a 260 GPH FASS will run on the order of $500. And then having either a big enough filter or a few filters in parallel isn't cheap either. If you look at a real fuel polishing rig, they really move the fuel.

I don't want to discourage people from trying to polish their fuel, even a cheap setup will help a lot if it is used often enough. However, if you are going to make your own, make sure that it has a high flow rate. The bigger the tank or if it has baffles, the greater the flowrate required.

Personally, I use all my diesel engines quite often so they get refueled regularly which helps a lot and I do have access to a polishing setup that is powerful enough to do smaller tanks although I don't make a habit of using it. I try to prefilter rather than filter once it is in the tank.