I bought a vessel that sat for 6 years with no machinery maintenance
. I used algae-x conditioner and their magnet on a vessel with WWII fuel tanks
. I needed to do a coastwise voyage of a few hundred miles and didn't want trouble. In addition to putting new fuel in separate tanks, I took along a case of primary and secondary filters.
The trip, Canada
to NW US was made in small craft warnings or better along with a bad bar crossing.
During the trip the magnet, checked later, caught so much rust that it's housing was almost plugged. All that would have been caught in the primary filter. As it was I never plugged a filter.
I think anybody with good mechanical skills and diesel
knowledge can make the equivalent of a fuel polisher, but if you have a proper filter system and use a good stabilizer for layup
times, you shouldn't need a polisher.