Fuel Polisshing?

[Gadzooks!]

Has anyone installed a fuel polishing system on an MV34? If so, please provide details.

It seems to me that with the addition of a filter and a couple Y-valves, one could use the fuel transfer motor to create a fuel polisher. Some unknowns, of course: e.g. is the motor powerful enough? Would there be priming problems (could provide a port at the filter or elsewhere to manually prime)?

[Tanah-Keeta]

I see fuel polishing beneficial for trawlers with large tanks..... My routine is to run until the main tank is about 1/4, then transfer fuel from the forward tank ( until it shows about 1/4) then drive for another day or so until it is convenient to fill both tanks. The point is that, if you are underway, fuel polishing is not needed because you are replacing the fuel regularly. If the boat has not been used for a long time, then maybe a portable polisher could be used .. however after 3 days of running you will have used enough fuel that a fill up would mitigate old fuel.

If you get a load of bad fuel, then all bets are off.... polishing would be needed or a lot of filters....

[duetto]

i agree with ron....use it. steve d'antonio wrote a good article a couple of years ago in passagemaker magazine about fuel polishing. it's not as simple as circulating the fuel.

[Gadzooks!]

Will look up the Passagemaker article. I probably read it at the time but retain only the feeling that they were generally highly in favor. Of course, trawlers are their thing.

I did get some bad fuel once and cleared it up using a homemade portable polisher. All it was was a pump and a big filter plus some plumbing.

Agree that polishing new soon-to-be-used fuel would be mostly a waste of time, tho it might extend the life of the primary filter. But by the time we start frequent usage in the spring, some of the fuel can be 6-8 months old.

The fact that primaries have to be changed attests to the fact that there is bad stuff in there. And our tanks have a thin coating of black goop on the bottom. The forward tank at least; have not checked the main. My assumption is that it is dead algae. We do faithfully use biocide.

[duetto]

you may want to try startron. based on tests i've read it will, over time, "dissolve" the goop. they also make a tank clean "shock treatment" which will loosen dirt in tank.

we have used both. we have used startron faithfully for 6 years/ 2000 hrs. have to say fuel has been clean. we did get a bad load of fuel and used the tank cleaner and that also cleaned up the fuel quickly.

[SecondWind]

DO NOT use Startron. I used it and continually clogged fuel filters, until I finally had to pull the tank and clean it. Bad stuff in a dirty tank.

[duetto]

terry points out one of the big dilemmas of fuel. starting with an unknown or perhaps bad situation what do you do. biocides will kill the critters but don't dispose of the bodies. your tank becomes a septic tank with the bodies decaying in a layer of acid which by the way doesn't play well with aluminum. i thought about this 6 years ago and decided to try and keep the tank clean. the risk was that i had a dirty tank and would have suffered the same problems as terry. fortunately for us we didn't and have been happy with the results so far. the key is to start with a clean tank. if you know you have algae/bacteria/goop inside the tank my advice would be to get it cleaned and then adopt a regime to keep it that way.

[billp]

I have been a huge supporter of fuel polishing since the mid-'90s when Alex Marcus (ESI) first began promoting it. Having sat through maybe 40 of his seminars at Trawler Port and Trawler Fest over the years, it is hard to dispute the value of these systems in the real world of cruising.

Having said that, however, I don't believe the capacity of the fuel tanks on the 34 justifies the expense of a proper system, and it is not worth doing otherwise. Understanding what is behind a good system, which is not just circulating fuel through a small diameter hose, is important. Someone mentioned Steve D'Antonio in this thread. Steve was not an early fan of fuel polishing, but he came to value the concept from the experiences of his customers, including me.

If you feel the need for a system for occasional use, such as after storing the boat for a long time, or getting water or bad fuel into the tanks, another approach might be to put together a portable system, using a high-flow rate 110VAC motor/transfer pump plumbed to as large a filter as you can justify. Many marine engine shops use portable systems. You also can share it among friends.

We found water in our port tank during our trip north from Stuart to Annapolis on our new-to-us 4108. I quickly learned how to drain water out of the on-engine filter (water got past the dual Racor 500s, but that is another story). When we got home, Bay Shore Marine used a portable unit to remove the rest of the water (and a bunch of bio-mass gunk) out of the port tank and we ran it on the starboard tank just to be sure. It worked very well. We probably had about four gallons of water total.

Even with this experience, I am unlikely to install a fuel polishing system. We just don't carry enough fuel on our cats. If I had bought a Krogen 48 with 1,200 gallons of fuel, you bet I would have a system.

Lots of companies make portable units, if you don't want to build one yourself.
BillP

[DickTuschick]

One additional note....the yanmar engines circulate about five (5) times as much fuel as they burn. thus if you are running at 3000 rpm you are actually circulating about 30 gal per hour thru your Racor filter. Run for 4 hours and you have polished your entire main tank !!!!
Safe cruising !!