Hi Bill,
Shortly after I purchased Libations I noticed that the sediment bowl in my fuel supply system was filling with a gelatinous goo. Since I was planning on coastal sailing where I thought wave action would really stir up any sediment or goo in the fuel tank and make things worse I elected to have the fuel polished and the tank cleaned. I ended up hiring MarineLube out of Alameda. The husband wife team showed up with their little work boat, unloaded a pump/filter apparatus, and removed a couple access plugs in the top of my tank. The process was simply that of pumping the existing fuel out of the tank, running it through a filter and water separator, and reintroducing the polished fuel to the tank in one continuous pumping/polishing step. They circulated the fuel in this manner for some time (about a half hour if I recall correctly). At the end of the process it was apparent that a quantity of water and sludge had been removed from the fuel/tank. During the pumping process the suction wand of the pump assembly was moved around inside the tank in an attempt to fully clean the corners, in between baffles, etc. I think I paid $300 or $400 for this service.
That must have been back in 2005 or 2006. The fuel polishing and tank cleaning greatly reduced the amount of goo that was accumulating in my sediment bowl. I now routinely change fuel filters every 50 - 75 hours and have had no problems with this schedule since the cleaning. This is in spite of a fair amount of coastal and off shore sailing where there has been ample boat motion to stir things up quite well.
So, all in all, my experience was and has been positive. As an aside, I do not add any fuel conditioner or biocide to my fuel. I top off the tank each fall so that it is nearly full through the winter months in order to minimize condensation that may occur within a partially empty tank during the wet season.
Good luck!
