Welcome to the Hatteras Owners Forum & Gallery. Sign Up or Login

Enter partial or full part description to search the Hatteras/Cabo parts catalog (for example: breaker or gauge)
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 10 of 19
  1. #1

    Using Detroits as Fuel Polishers

    I have about 200 gallons of year old diesel remaining in my 1100 gallon tank. My plan was to closely monitor the tank and run it down another 100 gallons before adding fuel.

    I noticed a bunch of soft tar balls settled in my Racor bowl and outside the filter. (No water thank goodness)
    I disassembled the Racor and gave it a good cleaning and replaced the primary filter with a new 10 micron.

    Two questions:
    1)Is there an fuel additive that will break up or re-suspend the tar balls?

    2) Am I being silly running my tank down this low?

    (actually 3 questions)
    3) In sunny Florida, is it better to keep the tank topped off or keep it low only adding what you need (plus safety margin)

  2. Re: Using Detroits as Fuel Polishers

    Tar balls?

    With only 200 gallons in the tank, get a fuel polishing outfit to come down and clean the fuel and the tank out properly. If one tank is contaminated, most likely the other(s) are too.

    As for keeping the tanks full or not, I don’t think it much matters. The air/ fuel vapor present in the tank doesn’t get exchanged with the outside air unless there are vents on both sides of the boat. YMMV.
    Last edited by kelpy; 02-20-2020 at 08:45 PM.

  3. #3

    Re: Using Detroits as Fuel Polishers

    No idea about the tar balls...

    200 to 100 USG out of a 1100 tank is ok as long as you are sure this is what you have. How do you know? Hopefully not a gauge but a dipstick. How was it calibrated? Was the stick supplied by the builder?

    At 100 USG you may have Issues with generator pick ups.
    Pascal
    Miami, FL
    1970 53 MY #325 Cummins 6CTAs
    2014 26' gaff rigged sloop
    2007 Sandbarhopper 13
    12' Westphal Cat boat

  4. #4

    Re: Using Detroits as Fuel Polishers

    If it’s been sitting all the algae should be on the bottom. I’d make sure the polisher pulls a plug or access plate off the top of the tank and uses a suction tube all the way to the bottom. I run tanks dry all the time when I need to maximize fuel range. This idea that running a tank low is bad makes no sense. The pickup tube sucks from the same place weather the tank is full or empty. If the tanks are really dirty anything below half tanks the fuel is going to be sloshing around in there anyway stirring things up.
    Water in the fuel. Back when we first put on the Racors a number of us that fished the offshore canyons out of Cape May started noticing water in the sediment bowls. After checking the fill cap orings I talked to Ray Meyers at Hatteras who was “the guy”. Ray said they were finding that even with the fuel coolers on the return lines the tanks were getting pretty warm after a good run. As the fuel is used it is drawing in moist spray filled air. Since the vents in a convertible are close to the waterline it’s worse. After a run as the tanks cool down the moisture condenses in the tank and turns back into water. The only way to stop this is to fill the tanks after every run to force the air out of the tank before it condenses.
    "DON'T BELIEVE ANYTHING YOU READ OR HEAR AND ONLY HALF OF WHAT YOU SEE" - BEN FRANKLIN




    Endless Summer
    1967 50c 12/71n DDA 525hp
    ex Miss Betsy
    owners:
    Howard P. Miller 1967-1974
    Richard F Hull 1974-1976
    Robert J. & R.Scott Smith 1976-present

  5. #5

    Re: Using Detroits as Fuel Polishers

    Quote Originally Posted by Pascal View Post

    200 to 100 USG out of a 1100 tank is ok as long as you are sure this is what you have. How do you know? Hopefully not a gauge but a dipstick. How was it calibrated? Was the stick supplied by the builder?
    .
    I have a dip stick for the tank which agrees with the reading I'm getting from my Tank Tender.

    Quote Originally Posted by rsmith View Post
    If it’s been sitting all the algae should be on the bottom. I’d make sure the polisher pulls a plug or access plate off the top of the tank and uses a suction tube all the way to the bottom. I run tanks dry all the time when I need to maximize fuel range. This idea that running a tank low is bad makes no sense. The pickup tube sucks from the same place weather the tank is full or empty. If the tanks are really dirty anything below half tanks the fuel is going to be sloshing around in there anyway stirring things up.
    Water in the fuel. Back when we first put on the Racors a number of us that fished the offshore canyons out of Cape May started noticing water in the sediment bowls. After checking the fill cap orings I talked to Ray Meyers at Hatteras who was “the guy”. Ray said they were finding that even with the fuel coolers on the return lines the tanks were getting pretty warm after a good run. As the fuel is used it is drawing in moist spray filled air. Since the vents in a convertible are close to the waterline it’s worse. After a run as the tanks cool down the moisture condenses in the tank and turns back into water. The only way to stop this is to fill the tanks after every run to force the air out of the tank before it condenses.
    Except I have a MY that mostly runs hull speed. As stated in my OP, there was no water observed in the Racor sediment bowls, just these little gooey black balls that look like tar. They break right up if rubbed between fingers. I figure it was a heavy faction of fuel oil, hence my question regarding an additive which would dissolve or re-suspend it.

  6. #6

    Re: Using Detroits as Fuel Polishers

    Even so in the marine environment especially Florida you are replacing volume of fuel used with humid air. The tar balls are most likely dead algae that was living on the fuel water interface. When you put an algaecide in the fuel like Biobor it kills the algae but then the dead floats around in the tank sticking to baffles and corners. We used to be in the boiler business we saw this same problem in large above ground tanks.
    "DON'T BELIEVE ANYTHING YOU READ OR HEAR AND ONLY HALF OF WHAT YOU SEE" - BEN FRANKLIN




    Endless Summer
    1967 50c 12/71n DDA 525hp
    ex Miss Betsy
    owners:
    Howard P. Miller 1967-1974
    Richard F Hull 1974-1976
    Robert J. & R.Scott Smith 1976-present

  7. #7

    Re: Using Detroits as Fuel Polishers

    Normal fuel tank pick up tubes do not extend to the very bottom of the tank by design.
    Gen-set pick up tubes are usually shorter.

    I have made deliverys where the boat is running fine until some nice wake/waves are encountered. The fuel sloshes a bit and fresh mud filters are suddenly clogged.

    The only way you are going to get the bug poo out of your tank bottoms is get a good fuel tank / fuel polish crew in there.
    Get your tanks cleaned correctly and sleep well.

  8. #8

    Re: Using Detroits as Fuel Polishers

    Wonder how easy it is to change filters on the fly in these babies?

    https://time.com/5789295/fuel-tank-debris-boeing-737/
    Semper Siesta
    Robert Clarkson
    ASLAN, 1983 55C #343
    Charleston, SC

  9. #9

    Re: Using Detroits as Fuel Polishers

    Quote Originally Posted by racclarkson@gmail.com View Post
    Wonder how easy it is to change filters on the fly in these babies?

    https://time.com/5789295/fuel-tank-debris-boeing-737/
    More fallout from the corporate climate evolution at Boeing. Beancounters proudly running the company.... "Unlike the engineers from before"..... McDonnel Douglas bought Boeing with it's own money. That was the beginning of the end. This is not over yet.

    Meanwhile.... Years ago a friend was ferrying a DC-10 back from Tel Aviv where it had been at a contract shop for heavy maintenance. At some point this side of 30W #3 gets a fuel filter bypass light. (Filter clogged, fuel now running unfiltered) After consulting with Houston they shut #3 down and continued. Not a big deal on an empty three engine airplane. Not long thereafter same thing happens to #1, and not much later #2. At this point they decided to put it on the ground, somewhere in the great white north. Just for shnitz and giggles they fire up #3 again. Never know what the other two are going to do. They put it on the ground uneventfully.

    Maintenance pulls the filters and finds....... Horse hair and cotton pulp. Turns out that the "technician" that had inspected the inside of the large center tank had done so navigating around on a thin mattress. (All organic materials and gluten free). This is normal. However he had accidentally left it in there. The first few hours of the flight the airplane fed all three engines out of the center tank..... This is normal and happens every day on most if not all airplanes out there. Takes too long to explain why. I've always felt less than 100% fuzzy about that. Anywho, that's how the crap got in all three filters.
    1978 53' Motor Yacht "LADY KAY V"
    Hull number 524
    Chesapeake Bay

  10. #10

    Re: Using Detroits as Fuel Polishers

    You have it backwards: Boeing took over Mc-Donnell Douglas when Harry Stonecipher sold us out. I was a mechanic in Flight Test at the time it happened and I remember it well. MD was in deep doo doo financially, the MD11 was not doing great sales wise, they had lost a huge fighter contract on a fly off and the first C17 was far behind its schedule. The company was on the brink, but could have pulled through until Stonecipher took over, merged us with Boeing as a very junior partner and got himself a good job at Boeing for the rest of his career.
    Michael & Beth
    Hull Number CV312
    63’ Cockpit Motor Yacht
    1986 model launched in August 1987

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts