No diesel engine ever had a problem from it's fuel being too clean.
With that in mind, and after some years listening/reading several
sides to the filtering/polishing debates, plus some industrial
experience along these lines, I finally added a pump & some new lines/
valves so that we can polish (sort of) our fuel.

Sailboats don't have as big a problem; our 2 fuel tanks are 150
gallons each. The fuel currently in them was pumped in August last
year. Before that, fuel was stored for up to 4 years.... maybe more by
previous owners. A smaller tank will have less water introduced by
condensation, and will have less gunk settling to the bottom. When we
first bought the boat & got underway, I was using 10 micron filters &
changing them every day for a week or so. Now I use the 2 micron
elements and only have to change them a couple times a season.

Our system is very simple, it draws fuel from either tank thru the
already-installed double Racor filter/seperator and then pumps it back
to either tank via taps installed at the bottom forward inboard corner
of each tank. So I can transfer fuel as well; also the pump discharge
is common to the fuel supply header so it can prime any of the diesel
fired equipment. The pump is a relatively cheap NAPA 12v recip that
moves about 30 gallons per hour.

This is too low a rate to be considered "true polishing" for our tanks
but I know for a fact it is cleaning gunk out. When initially run with
clean filter elements, there is no measurable pressure drop across the
filter. After a few hours running, the vacuum gage shows up to 15mm
and the pump is laboring (flow rate probably reduced considerably
too). Change the filter element, look at all the black & brown gooey
crud! Is it "polishing" or just pre-filtering? I don't care, I just
know that we will have less chance fo a fuel blockage underway, less
frequent secondary filter changes (expensive and a PITA), and the
engine will be getting cleaner fuel.

If we were going to be spending more time around the docks, I would
consider building a portable fuel polisher with a higher capacity pump
& some long flexible pickup/return hoses. There are people out there
who "polish" fuel & fuel tanks but the usual complaint is that the
service is too expensive to be cost effective for small sailboat
tanks. If it can save you an engine failure & repairs, then maybe it's
a bargain after all. Or a do-it-yourself system need not be very
expensive.

HTH
Doug King

wrote in message
ups.com...
No diesel engine ever had a problem from it's fuel being
too clean.
With that in mind, and after some years listening/reading
several
sides to the filtering/polishing debates, plus some
industrial
experience along these lines, I finally added a pump &
some new lines/
valves so that we can polish (sort of) our fuel.

Sailboats don't have as big a problem; our 2 fuel tanks
are 150
gallons each. The fuel currently in them was pumped in
August last
year. Before that, fuel was stored for up to 4 years....

4 years? Was it varnish?

SBV

On Apr 24, 11:08 pm, "Scotty" wrote:
wrote in message

ups.com...

No diesel engine ever had a problem from it's fuel being
too clean.
With that in mind, and after some years listening/reading
several
sides to the filtering/polishing debates, plus some
industrial
experience along these lines, I finally added a pump &
some new lines/
valves so that we can polish (sort of) our fuel.

Sailboats don't have as big a problem; our 2 fuel tanks
are 150
gallons each. The fuel currently in them was pumped in
August last
year. Before that, fuel was stored for up to 4 years....

4 years? Was it varnish?

SBV

That is a bit old, however on an island I once visited they had
diesel 40+ YO. As long as it's in a tank and polished its a-OK. I
installed a polishing system like Dougboats too this winter, quite
happy with it. After some shipyard time I'll get out and slosh things
about and polish properly.


Joe

"Joe" wrote in message
oups.com..
..
On Apr 24, 11:08 pm, "Scotty"
wrote:
them was pumped in
August last
year. Before that, fuel was stored for up to 4
years....

4 years? Was it varnish?

SBV

That is a bit old, however on an island I once visited
they had
diesel 40+ YO. As long as it's in a tank and polished its
a-OK. I
installed a polishing system like Dougboats too this
winter, quite
happy with it. After some shipyard time I'll get out and
slosh things
about and polish properly.


I've turned down free 300 gals , that was 2 years in a house
tank, had that varnish smell / look to it.

Scotty