Flat bottom boat keels

Discussion in 'Wooden Boat Building and Restoration' started by Christopher Rummel, Sep 27, 2021.

  1. Christopher Rummel
    Joined: Sep 2021
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    Location: Tucson Arizona

    Christopher Rummel Junior Member

    I plan to finally build Rube Allyn’s houseboat “Water Wagon”. For the last 50 years or so I have been carrying around his plans that where in Mechanix Illustrated, and two travel books he wrote, of his travels around Florida, in the late 1940s and early 1950s. I remember it being in an old National Geographic Magazine also.
    One of the modifications I think I should make is to fiberglass the hull. It has a flat hull 7’ x 20’. It has nine 2”x 2” keels on the bottom. In order to fiberglass, I understand I needed to round off the keels and filleting the inside corners. So the fiberglass wouldn’t have any 90 degree turns. I was wondering if that will reduce the effectiveness of the keel (by removing the 90 degree angles) and if it did would it be insignificant? The keels are attached to a plywood hull. There is no sub-floor bilge area, the plywood is also the inside cabin floor.
    Since the original plans were before fiberglass usage; and considering my age (how long I could realistically use it). I considered not fiber-glassing. However, after reading about the decline in Marine plywood in the last 70 years. The fact it will be setting in water most of the time. I figured I better.
    I remember my uncle telling me that many of the boat builders around St. Petersburg FL thought the boat was overrated. Rube Allyn was an outdoor fishing writer for the paper there. He knew how to get something in print. If anyone knows of anyone who had actually heard anything, or knew anyone who actually built it. I would appreciate any comments.
     
  2. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Welcome to the Forum Chris.

    Re those nine keels, they will be spaced approx 8" - that is a neat way of stiffening up the bottom panel, by adding the frames on the outside rather than the inside.
    Re 'fibreglass' - if you want to do this, use the appropriate cloth with epoxy resin - it is so much better for this purpose than polyester resin.
    I would be inclined to glass (with epoxy) the hull first, before adding the keels, and then basically regarding the keels as sacrificial (you could perhaps bolt them on, with adhesive sealant underneath, or even epoxy)

    Can you post a copy (perhaps a photo or two) of the plans here for reference please?
     
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  3. Will Gilmore
    Joined: Aug 2017
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    Location: Littleton, nh

    Will Gilmore Senior Member

    Is this the boat?
    upload_2021-9-27_3-39-6.png
    upload_2021-9-27_3-41-39.png
    Not much deck space, but an intriguing look to her. Reminds me of the Lost in Space Chariot
    upload_2021-9-27_3-45-33.png

    Maybe with the addition of a glass skin, the number of keels could be reduced and the same stiffness could be maintained. Reducing wetted surface should mean less power needed to push her.

    -Will
     
  4. Heimfried
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    Heimfried Senior Member

  5. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    @christopher it does make a lot of sense to take advantage of developments in materials and designs over the years, and to consider the boats in Heimfried's link above.

    Another alternative could be Bernd Kohlers houseboat designs -
    POWERcats https://ikarus342000.com/POWERcats.htm

    These are available in the USA from Duckworks, along with a range of other types of house / canal boats -
    Plans & Kits - Plans by type - Powerboats - Houseboats/Livaboards - Duckworks Boat Builders Supply https://duckworks.com/houseboats-livaboards/
     
  6. Christopher Rummel
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    Location: Tucson Arizona

    Christopher Rummel Junior Member

    Thanks for the advice. I will seriously consider it all. Especially fiber glassing the bottom flat and bolting the keels on. I know it is an ugly duckling. But the carpentry is simple enough that I can easily do it. Except for the bow, everything is 90 degrees. The materials are ones I can afford. I should be able to finish it in time to actually use it a lot. I will be using it to fish in some very shallow water back home in the Mosquito Lagoon, and Indian River, on the Florida East Coast. I also plan to live on it for a week or two at a time exploring other shallow water locations I used to fish in Florida. One more question. The angle of the bow from the drawings and pictures using a protractor appears to be 40 degrees. Does that seem reasonable? Thanks again.
     
  7. bajansailor
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    bajansailor Marine Surveyor

    Chris, boat design has progressed a lot in the last 50 years.
    Yes, building a simple box shaped boat should be a bit easier than building a more 'boat' shaped boat - but with good plans this should not be an issue.

    Can you post a photo of a drawing showing this please?

    I think that you would be much better off with a more modern design. Bear in mind that even if you have to buy plans, and the cost might seem to be substantial, the plans cost might well be only 1% of the final cost of the boat that you build.
     
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  8. Christopher Rummel
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    Christopher Rummel Junior Member

    I know this is really a shanty boat. I would use the outboards more to just move it to a new location where I will set a while. More of a floating cabin on a barge that I would move around. But I wanted the angle of the flat bow to be as efficient as practical (considering all the other limitations of the boat).
     
  9. Christopher Rummel
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    Location: Tucson Arizona

    Christopher Rummel Junior Member

    I know I am being motivated by some nostalgia here more than best new practices.
     
  10. bajansailor
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    bajansailor Marine Surveyor

    Are you planning on fitting her with twin O/B motors?
    If so, even more reason for building a boat shape, rather than a box shape.
    Re the angle of the bow - it does not show what happens below the waterline. Does it carry on in a straight line, or is it curved?
    If you are looking for 'efficiency' then a box is not the best place to start - even if it does have a raked bow.
     
  11. Will Gilmore
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    Will Gilmore Senior Member

    What is it about the box shape that makes it efficient as a cargo barge but doesn't work as a boat?
     
  12. Heimfried
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    Heimfried Senior Member

    Cargo barges are calculated based on economic figures (and are built often decades before). In Europe the typical US fuel price is (or was) considered "near zero" - so a boxy cargo barge is cheap to build and cheap to push. Is that a model for our future?

    Christpher says:
    As he focused the bow angle only may be he underestimates the influence of the transition between bow and bottom to efficiency so a hint should be appropriate.

    @christopher
    A very small change in the angle will make nearly no difference - a bigger change has possibly unwanted results regarding buoyancy and trim.
     
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  13. Christopher Rummel
    Joined: Sep 2021
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    Location: Tucson Arizona

    Christopher Rummel Junior Member

    Thank you for all your and ideas. I need to digest all this information and ideas now.
     
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