Diesel Boat Heaters

Discussion in 'Powerboats' started by Boston, Apr 19, 2010.

  1. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    Yeah fuel is not the issue,it's the ability to expand the system.

    The Kubs are naturally quite quiet and engine weighs 110 pds.Add another 60? for alternator and frame.
    Plus 50 pounds for the box.

    I've built 2 units,rubber mounted and cocooned in an aluminum box.
    Outside-fibreglass sheet,3/4 plywood,thick rubber layer,then internally a couple layers of sound material and from 5 feet away you can't hear it running.

    Outside of engine room-unless you look at the gauges you'd never know.
  2. mark775

    mark775 Guest

    Those are a killer without ventilation, Troy. People assume a tent breathes but it doesn't breath enuf when wet. I don't know anything about a Kubota - There is a six KW Northern Lights sitting at my local distributor I was thinking about... I just don't like the sound (I know some how to deal with it, I used to do some work in sound reduction when I was doing yachts. The single most important thing to do for sound, IMO, is to seperate the water from the air and run the water out under the waterline so it's not spitting) and having to come up with a load for the engine when you don't have a need...To me, that's why a little smaller set that is load-independant makes sense.
  3. Boston

    Boston Previous Member

    I can see that working for your needs Troy but for myself on the inside passage propane is just out of the question

    its not safe

    I want simple and reliable
    a one fuel system
    so if I use pellets to run my boiler I want to use pellets to run my heater
    if I use diesel to run my engine then I want diesel to run the heater

    propane is not acceptable as a heat source cause if it leaks it will tend to "sink" into the hull and just wait for an ignition source to set it off

    my two cents but I think propane is out of the question

  4. apex1

    apex1 Guest

    As much as I like the idea of building a boat with steam propulsion Boston, this is way out of sense in every aspect, to be built in a boat you are thinking of.

    And if it´s not me to find positive arguments for steam boats, who else would it be?

    I can go into deep on this subject if there really is a demand............


    this could probably be the cheapest solution for a skilled tinkerer:


    combined with a 1kw dc alternator, regulator (another 1000 to 1200$) and a common heat exchanger (closed loop) for your boiler / heater. You know that this 9kw engine produces another 9kw of heat.

    All in all maybe 3000$ in diy.

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    FAST FRED Senior Member

    Some observations,

    A friend used to use coal for heat , and hold down a Suit job in NYC.

    His solution was to get a ton of coal , the best he could find of anthricite, and bag it double in paper bags , and store the coal on the dock in steel garbage cans.On departure in the AM he would simply toss in a bag , returning home another bag , with a bit more draft would make the cabin toasty for the evening.

    ALL the complex Webasto or Espar heaters were really designed for trucks or busses.

    The difference is usually heat is needed with the vehicles operation , so the engine is ON and 14.4V is aviliable at the unit.

    On boats the dockside battery charging unit holds the voltage to 12.8 to 13.4 or so.

    This is the cause of the short and miserable operation of the units.

    Using kerosene ONLY is a huge help, as is boosting the voltage of the glow plug .

    The best solution we ever found was to operate the unit 100% of the time , and use a thermostat to reduce the voltage to the pump motor (as Espar does for "half") operation.

    The units would cycle between full and half to maintain boat temperatures, but as a product it want worth the effort , midnight calls , and crappy parts delivery.

    Dickinson or its rivals , IF you want warm hassle free winters.

  6. capt littlelegs
    Joined: Apr 2010
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    capt littlelegs New Member

    The problem with any unvented portable LPG heater even catalytic is the water vapour produced that will cause considerable condensation inside the boat. You need a drying heat on a boat. I remember reading about a couple who ended up in the Falklands and were using their flowerpot heater on top of the gas cooker. They didn't seem to realise why their bedding, clothes and carpets were always sopping wet and with mould everywhere! Although not a problem with catalytic heaters they also ran the risk of waking up dead in the morning from carbon monoxide poisoning!
  7. apex1

    apex1 Guest

    A real issue and often underestimated or just unknown!
  8. WestVanHan
    Joined: Aug 2009
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    Location: Vancouver

    WestVanHan Not a Senior Member

    The small Kubota is rated 7hp at 2800rpm...about 3500 watts-30 amps at 120AC after losses and proper loading.
    Running it at 2000 won't need much load (taken up by electric heater anyways) and use a heat exchanger.

    They used this exact system in the Abrams tanks to supply power,they get replaced quite often.Have seen them on ebay with low hours for very cheap.

    If more is needed,the unit Apex suggested would be perfect.
  9. Boston

    Boston Previous Member

    thanks I always appreciate the dose of reality
    I think in order to speed up the build process, once I actually set a hammer to the wood, I'll be sticking to a simple diesel system. Then I'll tinker with steam ideas and designs until I'm convinced of its viability and go from there. By then cost of diesel might just have gone through the roof again and I'll know a lot more about the boat and its chances of being run on steam.
    The system would need some form of secondary propulsion since steam takes a while to build up and there are those times when you need power and you need it now

    I tried to work out an electric system over and over but it just wasn't viable for this vessel as a primary source of power and I might come to the same conclusion about steam, but for now I'm just trying to hammer out a design for the hull and a method of construction that best suits both it and me. My electrical system is based around 4 of those big Rolls Surette batteries a back up gen set and one big *** alternator off the main engine. I also still want one or two of those vertical axis wind turbines and a small elect. back up drive belted to the drive shaft as some form of emergency power should my main diesel engine crap out on me

    Coal is a simple solution to the volume issues associated with wood as a heat source but pellets are much much cleaner and Im sure I can get a pellet stove to work on this thing without to much trouble. Not sue what stove I'll use yet but I'm sure whatever I chose I can bludgeon it into cooperating if I need to

    one thing I was kinda curious about was these diesel stoves though and from what I'm gathering they are ok but not great. I'm always looking for definitive answers and round these parts they are dam hard to come by so maybe just a pellet stove and a wood stove one in the wheel house and one in the aft cabin would work out well enough. I can run forced air all day long so installing a trunk line or a simple run is nothing and a few pipes and a blower later Im sure I can move heat to wherever I want it, assuming I can manage to keep a fire lit ( which funny as it sounds might be the tricky part )

    MR little legs I agree completely

  10. mark775

    mark775 Guest

    "boosting the voltage of the glow plug" - every other fault code I get is "insufficient voltage", 0052, as I recall. I am not an electrician - how would I do that without boosting too much? My brother is an electrical engineer for Siemens and I presume he cold tell me but he's not answering right now. I sometimes forget the Espar voltage sensitivity because it is the only thing on my boat like that - My boat is set up so that no matter what I do to my house bank, my cranking batteries are uneffected and I tend to therefore, be very hard on the house. I can hear it now; "aha! and he's blaming the Espar" - Well, thats only every other fault code...
    Thanks for that diesel motor/alternator idea, Richard. What alternator would you recommend? I can find ambulance alternators at 280 AMP . Now that I think of this, is the Kubota electric start only? it might be worthwhile to locate a pull-start diesel - Yanmar used to make one, but likely more expensive.
    Boston, we're going to have explored every avenue for you!
  11. mark775

    mark775 Guest

    There is a oil rig spewing oil and there is now a moritorium on drilling. We will see seven dollar diesel within a year.
    Bos, show us what pellet stove you are talking about - I havn't seen one of those since the craze thirty years ago...
  12. apex1

    apex1 Guest

  13. Boston

    Boston Previous Member

    well Mark the best time to be indecisive is long before I start building cause once I pick up that first chunk of wood I want go like a bat out of hell until its done. I like to have all my planning and changes done in the planing stage and actually stick to building in the building stage. I'm kinda nuts about that actually, used to charge a pretty penny for change orders in my old contracting biz.

    Random note
    I just had an interview for a job where the guy who recommended me is an x employee now working for those guys and the guy who interviewed me is an x subcontractor of mine. Pretty sure I got the job but it just goes to show what goes around comes around. They offered great pay full bennies and a decent position to start. Guy who used to be one of my subs says he will talk to the powers that be and let me know so
    fingers crossed

  14. Boston

    Boston Previous Member

    ya but if they had had the simple safety cap that every other country requires there is a chance that this would not have happened at all

    and agreed
    in the end its the consumer that pays for all the errors of big biz, wall street or Washington, oil or nuclear.

    let me see if I can dig up a pict of that horizontal feed system I was talking about

    I have a few articles that I saved you might find interesting

    this thing is supposed to be completely automated and I was thinking of fitting this to one of the Reliable steam companies boilers if I were to go with steam eventually


    and these guys have some nice little stoves
    ignore the prices I've found them for less than half what they are asking for on line


    anyway that should get you a good start on finding out about modern pellet stoves, they have come a long way and the old days of constantly tinkering with this and that are pretty much over.

    from what I've been able to gather what divides a good one from a bad one is how easy it is to initially calibrate the blower the feed rate and the temp sensor. Apparently some are self adjusting like the horizontal burner in the second link and some like the little wood stoves you might end up adjusting from time to time

  15. apex1

    apex1 Guest


    Not to discourage you, but I know what a proper steam engine setup means in reality!

    First point is: triple the engine room space at least.
    next: make it much higher than it would be for a Diesel! And double the calculated displacement of the vessel.

    third: install tank(s) for boiler water for at least the period of operation under the given fuel bunkers you can carry.

    four: have a condenser for your boiler water, and a good cocos fibre / charcoal filter to polish the boiler water behind the condenser! (try to get cocos fibre regularely)
    You know that you add lubricant to the steam before it enters the engine?!
    You must absolutely get rid of it before the condensed water enters the boiler again!!!

    Now buy all the aux. engines and the associated stuff. Generator, water injection, evaporator, circulation pump, etc. etc....

    The average steam boat has about 5 - 12 aux. steam engines!

    next, but not last: have a stoker / engineer while operating the boiler / engines (you can neither the boiler, nor the engine(s) leave unattended. No matter how sophisticated the installed technique may be.

    Get the certification to operate high pressure equipment (boiler ticket).

    Be prepared to invest the same amount in steam technique as you would invest in nuclear power. (or something in that ballpark)

    Be prepared to overhaul the boiler every 5 years at least. When the boiler goes through the dew point more than once a month, this is every other year instead.

    There are more points than these, but I assume that is enough for today.

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