Simple Polishing Filter

[NorthernFocus]

We're the 3rd owner of our 2008 vintage R25. Not knowing what kind of fuel hygiene habits the prior owners had and having a strong paranoia about fuel problems, I decided to clean the fuel tank. Well as you know that's easier said than done on these boats. So I set about designing a little fuel polishing skid. As I began to spec out parts it became evident that there was no real cheap way to do it. At least not for a robust package that could be easily set up when desired. Or left permanently installed. In the process of looking at parts and pieces, I ran across a simple solution. It was a bit more expensive than a do it yourself model but not unreasonable. Particularly considering the time saved.

The device is a Racor P510MAM fuel polishing filter. It is physically about the size of one of the 500 series turbine filters and has a pump built right into the top of the filter housing. It pumps 60gph though the filter. Elements are available for 2, 10, or 30 micron filtration. It comes with a marine grade switch for the pump and an installed WIF sensor but the detector is extra. It cost right around $500 plus another $50 or so for fittings.

The generator was removed from my boat by the previous owner but the fuel supply and return lines were still in place. They provided a convenient place to plumb up the polishing filter. I simply moved the supply from the outlet to the unused inlet port on the primary filter housing so fuel runs through the housing but doesn't have to pass through the 15gph rated element. If I decide to install it permanently the plumbing will be completely re-done.

So, anyhow, for any other clean fuel freaks out there, it's not a bad option. We'll find out tomorrow if it did NOT work. If it did, well we'll never know whether it did or if the fuel was already clean 🙁

 

[SGIDAVE]

Hello Dan,

Is it one of these?

dave

 

[NorthernFocus]

Hello Dan,

Is it one of these?

dave

zakly :mrgreen:

The real thing has an aluminum housing rather than the clear plastic advertising model. Also for anyone who might consider one, the in/out fittings don't come with it. And they're metric 🙁

 

[Glen]

I am also fanatical about fuel quality. I have two questions regarding the fuel polisher: 1) To be effective shouldn't the fuel polisher pull fuel from the bottom of the tank? 2) Does the fuel pick-up for the generator pull fuel from the bottom of the tank? I would have thought that the generator fuel pick-up would be well off the bottom of the tank to make certain that the generator can't cause the tank to run out of fuel, but I don't know if this fail safe feature is built into our boats.

While working on an R-29 with a D4 Volvo I was impressed by the amount of fuel (maybe 6 to 10 gal/hour?) that is pumped through the fuel filters and returned back to the tank whenever the engine is running. If all of our boats have similar fuel return systems than we are all slowly polishing our fuel whenever our engines are running.

 

[NorthernFocus]

...1) To be effective shouldn't the fuel polisher pull fuel from the bottom of the tank?

Ideally, sure. Unfortunately, CG regs don't allow fittings on the bottom of tanks any more. So all pickups are on top of the tank with a dip tube that typically stops within an inch of the bottom and is cut at an angle. The design has been used for years but is non-sensical. All it achieves is to leave water/trash in the bottom of the tank until you get in a rough seaway then it all gets sucked up at once.

2) Does the fuel pick-up for the generator pull fuel from the bottom of the tank?

Per the previous, no. On my boat the gen fuel pulled from a second outlet port on the filter housing.

While working on an R-29 with a D4 Volvo I was impressed by the amount of fuel (maybe 6 to 10 gal/hour?) that is pumped through the fuel filters and returned back to the tank whenever the engine is running. If all of our boats have similar fuel return systems than we are all slowly polishing our fuel whenever our engines are running.

When the engine is running, that's true. Unfortunately the majority of boats spend the VAST majority of time sitting static at the dock. Particularly in locations with seasonal boating. That's also when the tanks get water in them via condensation. Once the water is in there it's down hill. Fuel polishing is most useful during pre-season commissioning. But one does need to figure out how to stir the tank somehow. With a trailerable boat we have the option of running the polisher while we go for a drive 😉

For me it was likely a one time event. Once I'm satisfied that the tank is clean, practicing good hygiene will keep it that way.