I've done it on a DIY basis to try to get a lot of accumulated gunge out of a keel tank. Rigged up an old water pressure pump connected to a fuel filter, then pumped out about 25 litres from the bottom of the tank through a rigid plastic tube, through the filter, and into a clean plastic jerrycan. Tipped it all back as quickly as possible, so that the contents of the tank got stirred up, then repeated the process. Did that all day. Quite a messy process, so lots of old newspaper spread out on floor.
Verdict? Well, it did remove a lot of muck, because I had to change the filter element several times during the day. But it didn't stop the problem I'd been having of the fuel filter getting blocked when motoring at sea. Finally fixed that by enthusiastic use of Soltron.
I was on a mangusta 108 at dusseldorf and in the engineroom was a quite fabulous contraption - seemed to be a large centrifuge, specially designed for filetering and erm spinning the fuel and erm well, not sure but it looked fab and quite expensive. Is it this sort of mechanical device you mean? Or are you referring to additives?
There are many different types of fuel polishing systems from additivs to very cleverand complicated machines. Alot of fisherman in the states use mechanical ones as they are very popular with the big fleets.
It depends what you want from a fuel polishing system I could rant all night on about it but it may not serve your purpose, please be more specific.
No I'm looking at the mechanical system, permanently fitted. Big in the US (where I believe there are more problems with contaminated fuel). One of the systems I saw at Dusseldorf Boat show was the Algae-X system which I'm told is now fitted as an option on Elegance (Drettman).
I've read quite a lot about it in the American Journals - and most seem to swear by them - but no real information over here. I'm looking because I believe 90% of engine problems are caused by fuel contaminants. If there's a chance of minimising the risk for not a great outlay (about $2,000) why not at least look.
I've got a new boat coming soon and already we've been putting in S*****n from day one, for sea trials and the trip to Dusseldorf and back - not that I'm paranoid or anything