"Capt. JG" wrote

I just attended a diesel seminar on Saturday put on by one of the local
yards. That black crud looks very similar to the bacteria that they showed
us. Is that what you have? You might want to look at it under a
microscope. If so, they recommend a biocide (any will do, mentioned was
Biobor)

I use Star Tron which is an enzyme that causes any bacteria present to
detach from the tank walls and clump up so that it can be passed steadily to
the filters instead of going through all at once when stirred up in rough
water which is usually when you don't want to deal with a clogged filter.
It's a non-toxic alternative to biocide. I put it in with every batch of
fuel since each refueling can expose you to new bugs. I'm pretty sure it
works because I had a lot of stuff show up in the sediment bowl (pre
polishing system) right after I started using it.


According to the yard manager, who has about 30 years experience, one
should top off the tank as much and as often as possible as any
condensation is ultimately bad. He keeps a jerrycan with fuel in his
lockbox, so that when he returns and has only used a small amount, he can
top it off.

I see you missed the long thread on topping up tanks. Just because he did
it for 30 years doesn't mean it's necessary. Read the thread and come back.
Minimizing the surface area of fuel in contact with the air is a good thing
to do but it's a crazy obsession in the actual hassle/benifit analysis.


FYI, all #2 is identical, at least per state. You want to ensure that your
diesel has the right cetane number, typically in the 48-51 range, and if
yours is like ours in California (41 - mandated by state law), then you
can get a stanadyne additive to bring it up. Apparently, many of the long
haul truckers fill up in Nevada before they cross the border, since Nevada
serves the good stuff.

Now, this is interesting. I want to find out more although I expect Maine
isn't mandating weak fuel.


He also recommeded a dual primary system if you sail offshore.


That's essentially what I have although one of the filters is of higher
retention capacity and running separately all the time.

Another aspect of my system is that the fuel is being sucked from the tank
much, much, faster than the engine would draw (and this is especially an
issue on my Yanmar where the return line doesn't go to the tank). This
means that crud drifting around just below or near the pickup is
significantly more likely to be drawn in and recirculated through my big
Shelco filter.

--
Roger Long

"Roger Long" wrote in message
...
"Capt. JG" wrote

I just attended a diesel seminar on Saturday put on by one of the local
yards. That black crud looks very similar to the bacteria that they
showed us. Is that what you have? You might want to look at it under a
microscope. If so, they recommend a biocide (any will do, mentioned was
Biobor)

I use Star Tron which is an enzyme that causes any bacteria present to
detach from the tank walls and clump up so that it can be passed steadily
to the filters instead of going through all at once when stirred up in
rough water which is usually when you don't want to deal with a clogged
filter. It's a non-toxic alternative to biocide. I put it in with every
batch of fuel since each refueling can expose you to new bugs. I'm pretty
sure it works because I had a lot of stuff show up in the sediment bowl
(pre polishing system) right after I started using it.

Interesting... I'll check out Star Tron. Thanks.


According to the yard manager, who has about 30 years experience, one
should top off the tank as much and as often as possible as any
condensation is ultimately bad. He keeps a jerrycan with fuel in his
lockbox, so that when he returns and has only used a small amount, he can
top it off.

I see you missed the long thread on topping up tanks. Just because he did
it for 30 years doesn't mean it's necessary. Read the thread and come
back. Minimizing the surface area of fuel in contact with the air is a
good thing to do but it's a crazy obsession in the actual hassle/benifit
analysis.

No... didn't miss it. He's dealing with bio/water issues every day. I think
I'll trust his experience, although he didn't say to be obsessive about it.
He's advocating exactly that... minimizing the surface area. There's always
going to be water in the bottom of the tank. The bacteria eats the diesel
and lives at the line between the two. It's not just about condensation, as
there might be another avenue for water intrusion, such as a poor seal on
the filler cap. I don't think taking a couple of minutes to top off a tank
is obsessive. Seems like a good idea, especially keeping a jerrycan in the
box. It's a fairly long drive to get to a fuel dock for me.


FYI, all #2 is identical, at least per state. You want to ensure that
your diesel has the right cetane number, typically in the 48-51 range,
and if yours is like ours in California (41 - mandated by state law),
then you can get a stanadyne additive to bring it up. Apparently, many of
the long haul truckers fill up in Nevada before they cross the border,
since Nevada serves the good stuff.

Now, this is interesting. I want to find out more although I expect Maine
isn't mandating weak fuel.

I believe it's a low sulfur content issue, with the desire to lower air
pollution levels.


He also recommeded a dual primary system if you sail offshore.


That's essentially what I have although one of the filters is of higher
retention capacity and running separately all the time.

Another aspect of my system is that the fuel is being sucked from the tank
much, much, faster than the engine would draw (and this is especially an
issue on my Yanmar where the return line doesn't go to the tank). This
means that crud drifting around just below or near the pickup is
significantly more likely to be drawn in and recirculated through my big
Shelco filter.

What micron sizing do you use for the primary and secondary?


--
"j" ganz @@
www.sailnow.com

"Capt. JG" wrote

No... didn't miss it. He's dealing with bio/water issues every day. I
think I'll trust his experience, although he didn't say to be obsessive
about it. He's advocating exactly that... minimizing the surface area.

But he's missing out on the frequent opportunity to have the sloshing of a
partially full fuel tank knock off some bio film sticking to the sides.
He's also increasing the average age of the fuel with its absorbed water
content and oxidation. I've been working with commercial boat operators for
nearly four decades and never heard of trying to keep fuel tanks topped up
until this newsgroup.

The yard manager I brought my non-running engine to when the boat arrived in
Portland had similar or more experience. He successfully diagnosed that all
it needed was a thorough cleaning after the Yamaha shop and dealer in MI
told me it needed two new injectors and possibly an injector pump. The
engine has been running perfectly for three seasons on those components.
That gives him a lot of street cred in my book. His position on fuel was
that you should use up as much as you can before refueling so that most of
what you are burning is as fresh as possible. Why do experienced people
differ on points like this? Because it doesn't make much difference.
Topping off might make sense for the once a month weekender but would be
crazy for the almost daily sailor such as myself whether it was going to the
fuel dock and standing in line, doing the docking and undocking, etc., for a
gallon or lugging a can all the way down the dock at the end of the sailing
day when tired guests want to get home. The fuel sitting in that can is as
likely to go bad as what is in the tank. Do you keep topping up the can
that you top up the tank with? Where does it end?

What micron sizing do you use for the primary and secondary?

The Racor primary is 2 Mu because the polishing system keeps much crud from
every reaching it and it is oversized for the engine so there is no downside
to the finer element. It's pressure fed by the electric fuel pump.

The secondary is a Yamaha engine mounted filter and probably 10 Mu. Since
only their elements fit, I have to buy whatever they supply for the engine
anyway.

The polishing filter is 10 Mu but, as Rich H points out, will take out
smaller stuff because the fuel goes through it many times and it is a depth
filter instead of a surface filter. It also gets finer as it loads up.

--
Roger Long

"Roger Long" wrote in message
...
"Capt. JG" wrote

No... didn't miss it. He's dealing with bio/water issues every day. I
think I'll trust his experience, although he didn't say to be obsessive
about it. He's advocating exactly that... minimizing the surface area.

But he's missing out on the frequent opportunity to have the sloshing of a
partially full fuel tank knock off some bio film sticking to the sides.
He's also increasing the average age of the fuel with its absorbed water
content and oxidation. I've been working with commercial boat operators
for nearly four decades and never heard of trying to keep fuel tanks
topped up until this newsgroup.

Water absorption in diesel? Seems to me that would be a very, very small
issue, given that they don't mix. If the bio is stuck to the sides, why
would you want to knock it free? Better to kill it, filter the fuel and be
done. Do commercial boat operators let their boats sit for weeks at a time?
Seems to me that they would use their engines frequently, then fillerup,
then repeat. Thus, they are, in a sense, topping up, except the fuel is
lower when they start.

The yard manager I brought my non-running engine to when the boat arrived
in Portland had similar or more experience. He successfully diagnosed
that all it needed was a thorough cleaning after the Yamaha shop and
dealer in MI told me it needed two new injectors and possibly an injector
pump. The engine has been running perfectly for three seasons on those
components. That gives him a lot of street cred in my book. His position
on fuel was that you should use up as much as you can before refueling so
that most of what you are burning is as fresh as possible. Why do
experienced people differ on points like this? Because it doesn't make
much difference. Topping off might make sense for the once a month
weekender but would be crazy for the almost daily sailor such as myself
whether it was going to the fuel dock and standing in line, doing the
docking and undocking, etc., for a gallon or lugging a can all the way
down the dock at the end of the sailing day when tired guests want to get
home. The fuel sitting in that can is as likely to go bad as what is in
the tank. Do you keep topping up the can that you top up the tank with?
Where does it end?

Well, that's what I'm talking about... the once-a-month or slightly more
use. I've had the same diesel, less one topping off, for two years. I
haven't detected any difference in performance, so I don't think the
degradation issue is real (enough).

Ummm... my dock box is about 2 feet from my boat. I have a cart to move the
jug of fuel if I can't lift 3 gallons? Seems pretty easy.

What micron sizing do you use for the primary and secondary?

The Racor primary is 2 Mu because the polishing system keeps much crud
from every reaching it and it is oversized for the engine so there is no
downside to the finer element. It's pressure fed by the electric fuel
pump.

The secondary is a Yamaha engine mounted filter and probably 10 Mu. Since
only their elements fit, I have to buy whatever they supply for the engine
anyway.

The polishing filter is 10 Mu but, as Rich H points out, will take out
smaller stuff because the fuel goes through it many times and it is a
depth filter instead of a surface filter. It also gets finer as it loads
up.




--
"j" ganz @@
www.sailnow.com

"Capt. JG" wrote

Water absorption in diesel? Seems to me that would be a very, very small
issue, given that they don't mix.

But they do. See Rich H post below.

If the bio is stuck to the sides, why would you want to knock it free?

So that it can get into the filters to be removed and not come off at an
inconvienient time. Biocide is just a way of assisting its removal but the
stuff is nasty and tends to dump a lot of stuff into your filter system all
at once if the tank is badly fouled. The mechanical action of slack tanks
gets some of it into the system more gradually; especially with some
assistance from something like StarTron.

Keeping the tank "topped up" to the extent practical in normal operation
usually means that there will be full air and water vapor access to the
entire surface of the fuel. The difference between that and a slack tank is
insignificant (for a nearly straight sided tank) and, as Rich points out,
more fuel volume for the same air/fuel contact area means more water
absorbtion.

--
Roger Long

The issue of one 'sludging' ones filters from a cruddy tank is more
than just a 'fine point'. Just earlier this year, supposedly a Brit
lost his boat onto the jetty into Charleston SC Harbor when his engine
failed and he got caught in the rage of the inlet.

..... and for that very reason its a good idea to have a well
maintained fuel system, even a few gallon 'day tank' that holds back a
few gallons all 'ready to go' in case of such an event. The more and
more I think of it a small reserve tank of a few gallons makes all the
sense in the world - enabling one to motor on an hour or two; instead
of power-puking into the bilge while trying to change a damn filter
set. :-)

That constantly replenishing emergency tank idea of yours is one of the best
I've seen in this group. I'm still trying to figure out how I might
implement it but space, even for just the gallon I would need, is pretty
tight in a 32 foot boat.

I think it's very long odds that that the big Shelco filter would suddenly
load up. I would have advance warning from the Racor flow stopping and it
ought to take a lot longer for the Shelco to become critical. If I had to
change out a Racor filter, I would focus on getting into a safer position.
I also have two tanks so switching to the other one as well as switching the
fuel supply to the polishing output would be part of the drill if the Racor
loaded up. I'm a sailboat as well so I usually have an alternative
propulsion source.

--
Roger Long

"Roger Long" wrote in message
...
"Capt. JG" wrote

Water absorption in diesel? Seems to me that would be a very, very small
issue, given that they don't mix.

But they do. See Rich H post below.

If the bio is stuck to the sides, why would you want to knock it free?

So that it can get into the filters to be removed and not come off at an
inconvienient time. Biocide is just a way of assisting its removal but
the stuff is nasty and tends to dump a lot of stuff into your filter
system all at once if the tank is badly fouled. The mechanical action of
slack tanks gets some of it into the system more gradually; especially
with some assistance from something like StarTron.

Star Tron disperses the bacteria, but it doesn't do anything for a badly
fouled tank. If you're talking about a tank that's pretty good, maintained
with good fuel and you're careful about water egress, then the amount of
bacteria stuck to the sides would be minimal. In fact, they would die when
covered with fuel, and then they would pass naturally out of the tank. If
action is needed to get the bacteria out, I would much rather take that
action in a known timeframe vs. have it slowly clog a filter. If you're
going that route, then get a pressure gauge and put it on the filter. Then,
you'll know when the bacteria are starting to clog it. I can't imagine
wanting the sloshing action to break loose a bunch of decent size pieces and
have it immediately kill the engine.

If one has a badly fouled tank, that needs to be dealt with next to the
dock, not at sea.

Keeping the tank "topped up" to the extent practical in normal operation
usually means that there will be full air and water vapor access to the
entire surface of the fuel. The difference between that and a slack tank
is insignificant (for a nearly straight sided tank) and, as Rich points
out, more fuel volume for the same air/fuel contact area means more water
absorbtion.

I don't understand. If the tank if full, it's full. If you're using the
engine, you're using the engine, and when you get back and top it off with a
couple of gallons, it's full again, and whatever bacteria is alive for that
brief period when it's not full will quickly die and drop to the bottom. I
also don't understand the "absorption" issue with diesel. The diesel and
water don't mix, so whatever there is would be minimal to say the least and
it certainly won't hold bacteria.


--
"j" ganz @@
www.sailnow.com

"The diesel and water don't mix"
NOT so.

Water to a small amount dissolves in diesel
Diesel to a small amount dissolves in water
Emulsions are formed between the two phases of oil and water ... and
disperse throughout the oil

Only FREE water doesnt mix with water as it has gravimetrically
settled out of the oil due to gravity.


THREE phases of water in oil: Free water, dissolved water, emulsified
water.

This whole subject could be easily put to bed by calling your local
fuel polisher and asking the age of boats that need polishing.
I think you'll find all the 70's and 80's need cleaning and the 90's
will need cleaning in the next few years. Anything newer and there is no
problem. Meaning that if your system is clean, it's probably good for 20
years. At least, that's the way it is in the Puget Sound area. I suppose
warmer, more humid areas could be worse.
That said, I run dual Racors mainly because they were freebies and my
neighbor polished my fuel when I installed the Racors.

Gordon