Manufactured by Marsh Marine...Tank Cleaning Professionals
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DIESEL FUEL ... Keeping It Clean
Marshall Solomon, Marsh Marine
I
am
often
asked,
“What
can
I
do
as
a
boat
owner
to
keep
my
diesel
fuel
clean?”
Without
clean
fuel
your
boat
is
not
dependable,
safe,
or
fun.
Maybe
you’ve
been
lucky
and
never
been
stranded
by
clogged
fuel
filters,
but
have
no
doubt,
when
it
does
happen,
it
will
be
a
very
bad
day
boating!
Furthermore,
with
the
cost of fuel rising, this issue is becoming ever more important.
I
n
previous
articles,
I’ve
written
about
what
can
happen
as
fuel
ages
and
sits
for
extended
periods
of
time.
If
you’ve
followed
these
stories,
then
you
know
there
are
two
major
contaminants
which
can
spoil
your
fuel;
water
and
sludge
.
Notice
here
that
I
have
not
listed
Algae
.
I
hope
by
now
most
of
you
have
learned
enough
from
my
articles
to
know
that
Algae
cannot
exist
in
your
fuel
or
tank.
The
term
is
often
incorrectly
used
to
describe
the
black,
gooey
mess
that
typically
is
found
in
your
fuel
filters.
This
is
not
Algae;
it
is
break down fuel and is actually a substance called
Asphaltenes
.
W
ater
is
probably
the
worst
contaminant.
Water
will
do
serious
damage
to
your
fuel
delivery
machinery,
namely
your
fuel
pump
and
certainly
your
fuel
injectors.
Injectors
are
meant
to
spray
diesel
fuel
into
the
engine’s
cylinders
under
extreme
pressure.
This
spray
must
be
so
fine
that
is
it
is
virtually
a
vapor.
Too
heavy
a
spray
and
the
fuel
will
not
ignite.
To
accomplish
this,
the
injectors
have
spray
nozzles
which
have
minute
holes
in
them.
Depending
on
the
type,
these
holes
usually
range
in
size
from
7
to
10
thousands
of
an
inch
in
diameter.
Visualize
holes
which
are
just
twice
that
of
a
human
hair!
If
water
is
pumped
through
these
hot
injector
tips
the
holes
become
eroded
destroying
the
tip’s
ability
to
create
a
proper
vapor
pattern.
Sometimes
the
water
will
crystallize
the
tip
rendering
it
useless.
The
point
here
is
that
water
can
cause
serious
and
expensive
engine
damage.
Most
of
the
time
water
in
the
fuel
will
settle
to
the
bottom
of
the
tank.
Here
it
can
be
removed
without
damaging
the
fuel,
but
it
can
also
become
so
mixed
into
the
fuel
it
becomes
homogenized.
When
this
happens
it
will
never
separate
from
the
fuel
and
all
the
fuel
must
be
discarded.
Water
homogenized
fuel
has
a
milky
pink
color
(See
photo
1).
This
is
the
most
damaging
fuel
contaminant. Run it long and you will destroy your fuel delivery system.
T
he
next
and
most
often
found
contaminant
is
sludge.
I
use
sludge
as
a
collective
term
for
it
can
be
either
inert
or
biological
.
Biological
sludge
is
caused
by
bacteria
and/or
fungi
growing
in
the
diesel
fuel
where
water
is
present.
Believe
it
or
not,
but
this,
from
my
experience
in
having
cleaned
hundreds
and
hundreds
of
tanks,
is
actually
rare.
It
cannot
occur
without
the
presence
of
water
since
this
is
needed
for
the
biological
to
obtain
oxygen.
Though
rare,
this
is
another
very
bad
condition
to
clean
up.
Inert
sludge
is
the
most
commonly
found.
This
brown
to
black
goop
is
what
has
become
known
as
Algae.
It
seems
to
be
alive
since
it
appears
to
grow
in
the
fuel.
This
“growing”
process
is
really
microscopic
fuel
components
breaking
down
and
forming
larger
clusters.
This
clustering
tendency
is
called
agglomeration
and
as
previously
stated,
is
Asphaltenes
(See
Photo
2).
Call
it
what
you
might,
this
is
the
substance
most
often
found
in
your
fuel. Fortunately, it is the easiest to prevent. Let’s see how: