Boat Forum / Building / September 2003

Hi

Eh, ---- american ?
It couldn't be a jar of Rom hidden away back 1929 ?

P.C.

I have no problem using 'old' diesel fuel. I just salvaged 160 gal that was
6-8 years old and it is clean and clear. Most likely my fuel had  some
biocide put in it to retard the growth of bacteria in the bottom of the tank
(if water is present).

In your case, I'm not sure what has cause this fuel to be reduced to syrup.
I have seen this happen with really old gasoline..

The simplest thing, would be to mix it with enough heating fuel and burn it
in your heater. You might do this as part of the tank rinsing process since
clean diesel fuel should clean up the tank.

My local automotive/truck mechanic heats his shop with a mixture of fuel oil
and old crankcase oil.

I recommend you burn it rather than trying to dispose of it since most
disposal outfits will charge you more than the fuel cost new (then, I
suspect,  just polish it or mix it with good fuel and sell it).

In anticipation of buying a boat that might have a lot of old diesel
(which turned out to be Fintry, about 2000 liters), I asked about old
diesel fuel at the booths of all the fuel companies at the New Orleans
Workboat Show last December. I got consistent answers more or less as
follows:

Diesel, unlike gasoline, does not deteriorate on its own.  Ten year
old diesel should be just fine.  But (there's always a "but") diesel
does support the growth of bacteria if there's water in the tank or if
the tank gains water over time from condensation as the air moves in
and out of the vent with changes in temperature.

Are you certain it is diesel (gasoil), not gasoline (petrol, essence)?
Your description sounds like old gasoline.

If you are certain it is not gasoline, if it burns and will flow
through the jet, you can probably use it in a heater.  I wouldn't use
it in a modern engine, as they are sensitive not only to clogging the
injectors but to the lubricity (lubricating ability) of the fuel and
you could do a lot of damage.

Use judgement on cleaning the tank -- it depends on whether the stuff
leaves a residue behind.

Jim Woodward
www.mvFintry.com