Page 13 of 13 FirstFirst ... 31213
Results 421 to 436 of 436

Thread: Skookum Maru

  1. #421
    Join Date
    Sep 2007
    Posts
    1,875

    Default Re: Skookum Maru

    It pumps the expansion tank dry first. Some fluid would by pass the hole, but no water would get sucked in until the pressure dropped below the suction side pressure level.

  2. #422
    Join Date
    Nov 2014
    Location
    Seattle, WA
    Posts
    4,083

    Default Re: Skookum Maru

    Good question. Ok, I haven't really been thinking about this but what I expect to happen is that since the system is under pressure if the cooler is breached underwater it will expel a certain amount of coolant until the system reaches pressure equilibrium with the surrounding water. At that point the pump should continue to circulate raw water unless it loses prime. As Ron notes, I don't think it can actually lose all of the coolant unless there is an opening to let air in. Which can't happen in a sealed system (e.g. one with a pressure cap on the header tank). But this is just coming from my shade tree mechanic experience so I could be entirely wrong.
    Last edited by cstevens; 09-22-2019 at 08:53 PM.
    - Chris

    Life is short. Go boating now!

  3. #423
    Join Date
    Nov 2014
    Location
    Seattle, WA
    Posts
    4,083

    Default Re: Skookum Maru

    Quote Originally Posted by navydog View Post
    It pumps the expansion tank dry first. Some fluid would by pass the hole, but no water would get sucked in until the pressure dropped below the suction side pressure level.
    Ok but how does it pump the tank dry if there is no way for air to get into the tank? At least on Petrel there is a pressure cap on the tank so it is not open to the atmosphere. I think we are saying pretty much the same thing regarding the expulsion of fluid under pressure, I just don't see how it can lose *all* the fluid.
    - Chris

    Life is short. Go boating now!

  4. #424
    Join Date
    Dec 2009
    Location
    Vancouver Island
    Posts
    1,980

    Default Re: Skookum Maru

    I'm pretty sure the fix would be to repair the broken pipe and flush the system. Should continue to work after rupture until the unfiltered circuit plugs up with debris, perhaps not that long around here, judging from my raw water strainer. / Jim

  5. #425
    Join Date
    Sep 2007
    Posts
    1,875

    Default Re: Skookum Maru

    Quote Originally Posted by cstevens View Post
    Ok but how does it pump the tank dry if there is no way for air to get into the tank? At least on Petrel there is a pressure cap on the tank so it is not open to the atmosphere. I think we are saying pretty much the same thing regarding the expulsion of fluid under pressure, I just don't see how it can lose *all* the fluid.
    The expansion tank is under pressure from heated air. The low pressure from a hole will let the hot air push the fluid out. Eventually it would pull raw water in, but the system would be pulsating and not very efficient.

  6. #426
    Join Date
    Oct 2014
    Location
    SW Washington/ At Sea
    Posts
    349

    Default Re: Skookum Maru

    If the suction side is coming from the keel cooler the head pressure from the water will prime the pump...agreed it isn't an optimum setup but it won't go completely dry. I don't think it's really an issue though...the location of the cooler protects it as mentioned before.

  7. #427
    Join Date
    Nov 2014
    Location
    Seattle, WA
    Posts
    4,083

    Default Re: Skookum Maru

    Well, I think we are generally in agreement that it might continue to cool the engine or it might not depending, but in any event it’s not the most likely way you could ruin your day on the water. Seems like it will just have to remain a thought experiment unless anyone wants to cut a hole in their keel cooler in the spirit of science. No? Thought not. Ok then.
    - Chris

    Life is short. Go boating now!

  8. #428
    Join Date
    Apr 2010
    Location
    South Australia and Tasmania
    Posts
    19,894

    Default

    Guys it will just run like a raw water cooled system. Not rocket surgery.

    Sent from my CPH1851 using Tapatalk

  9. #429
    Join Date
    Sep 2007
    Posts
    1,875

    Default Re: Skookum Maru

    There is no raw water intake so it will not run the same.

  10. #430
    Join Date
    Oct 2018
    Location
    lagunitas, ca, usa
    Posts
    645

    Default Re: Skookum Maru

    The part that decided me was that, if anything happens to a keel cooler you have to haul the boat to fix it. With the inboard heat exchanger method, just close the seacock and get out the wrenches.

    I think the principle of a keel cooler is better. But in practice, it's real nice to be able to fix stuff anywhere, anytime.

    That's assuming that the seacock doesn't let go, which is something we just have to live with.

  11. #431
    Join Date
    Jan 2008
    Location
    Lynden, Wa
    Posts
    3,603

    Default Re: Skookum Maru

    Quote Originally Posted by cstevens View Post
    Fall has descended in earnest here in the Pacific Northwest. But we had family in town recently for a visit which coincided with a brief break in the weather so we took everyone for a tour around the lake in between rainy days.



    And now that we have Skookum Maru down here in Seattle we are looking forward to fall and winter cruising in Puget Sound. Poulsbo, Gig Harbor, Brownsville and other local destinations are only a couple of hours away. Time to fire up the diesel stove, make up a pot of hot chocolate, and break out the books and board games to while away the hours as the rain patters on the deck.


    That sounds amazing. What a lovely way to spend some time.
    There's the plan, then there's what actually happens.

    Ben Sebens, RN

    15' Welsford Navigator Inconceivable
    16' W. Simmons Mattinicus double ender ​Matty

  12. #432
    Join Date
    Apr 2012
    Location
    San Diego and Gabriola
    Posts
    195

    Default Re: Skookum Maru

    Quote Originally Posted by BBSebens View Post
    That sounds amazing. What a lovely way to spend some time.
    Yes! Chris certainly has put together a good winter set up there.

  13. #433
    Join Date
    Nov 2014
    Location
    Seattle, WA
    Posts
    4,083

    Default Re: Skookum Maru

    Not much happening on Skookum Maru right now. My plans for winter cruising were foiled by work commitments, including a project that required a lot of travel between August and December. Then we had the holidays and then family staying with us again. But I have hopes for some free time in the next few weeks so we will see.

    I did get one project accomplished recently - adding another section to extend the height of the stove pipe.



    It's a bit ungainly but with the extension in place the stove seems to burn far more cleanly. The stove is lit in that photo above although you would never know by looking at it. I'm currently working aboard with the stove running on natural draft only (no fan), a nice yellow flame, and no visible smoke at all coming from the stack.



    Not a bad way to spend a cold, wet and gusty January day in Seattle. Now if I just had some half and half in the fridge for my coffee...
    - Chris

    Life is short. Go boating now!

  14. #434
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    4,214

    Default Re: Skookum Maru

    draft = good = great Chris! Nothing I hate seeing more is incomplete fuel burning because it's not hot enough. Question, is the burner a pot type with a part that gets red to bright yellow hot?

    edit.. found my answer LOL the ring is called a "superheater"
    Last edited by DeniseO30; 01-07-2020 at 02:23 PM.
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

  15. #435
    Join Date
    Nov 2014
    Location
    Seattle, WA
    Posts
    4,083

    Default Re: Skookum Maru

    Yep - that's it Denise. My understanding is that the "superheater" heats the fuel so that it will vaporize and burn cleanly above the ring rather than down in the pot itself. Seems to be working great. If you read about diesel stoves and heaters on the various forums you will find all sorts of complaints about sooty, smoky, smelly diesel burners but all I can say is that they work great given the proper air/fuel mixture and good draft. Skookum Maru is toasty warm and the only scent is from the canola oil that I used to season the cast iron stove top. Smells faintly like french fries in here. Which reminds me that I need to heat up my lunch!
    - Chris

    Life is short. Go boating now!

  16. #436
    Join Date
    Jan 2009
    Location
    se pa (Bristol PA)
    Posts
    4,214

    Default Re: Skookum Maru

    That's a good and bad thing about the fuel oil burners they have to be at a high temperature otherwise they soot n smell. Kerosene heaters will smell also the wick eventually turns to Glass and needs to be trimmed because of the high temperatures involved,
    Denise, Bristol PA, Oday30, Anchor Yacht Club, On tidal Delaware River. my current project; http://forum.woodenboat.com/showthre...0-Ducker-Resto

Posting Permissions

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