Boat with No Keel!

Discussion in 'Boat Design' started by Kokanee-B, Apr 26, 2009.

  1. Kokanee-B
    Joined: Apr 2009
    Posts: 1
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    Location: England

    Kokanee-B New Member

    I am a new member, but not a boat builder. I hope some of your members might have some suggestions or ideas for me to modify a utility style boat.

    I have been given homemade boat, solidly crafted, which was built primarily as a fishing boat.

    It is a fully ribbed, double-skinned with ply, then fiberglassed.

    Length- 11' 1"

    Beam-6' 1"

    Weight- 800 lbs. (approx)

    External Depth- 23"

    It is very well made except for one small thing, the chap forgot to build a keel on it. On its maiden launch in the river, it sat well in the water but skates in all directions when an outboard is attached.

    I am not an experienced DIYer but have been thinking about a few solutions. Someone has offered to assist me who is very capable but is not a boat builder either, but has worked with fiberglass.

    I would really prefer not to break through the fiberglass as it is so solid and well finished. It has been sitting in my garden for several years and is still in very good condition.

    Would an external swing keel work and how would it be affixed? Or does anyone have any ideas?

    Please see photos. The lidded well at the bow is for storage. Thanks. DSC00693.JPG

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    DSC00696.JPG

    DSC00698.JPG
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    It's very likely the "skating" issue is probably a result of the very poor hull form selected. It appears the stern is a straight run from midship in plan view. This creates steering issues to say the least. This coupled with the fact it's absurdly heavy for the size of craft it is. An example would be an 11' powerboat design of mine that I did a few years ago. The bare hull (which is what you have) weighs about 100 pounds.

    A skeg might solve some of the issues associated with a shape like this, but you'll probably have other issues as well, once you get it up and going. Maybe twin skegs, to permit beaching upright and better flow to the prop, though you'll lose the protection of a single, centerline skeg. The skeg can be attached with screws, through bolts or lags, of course in a bedding compound. Don't even think about a swing keel, which is a sailboat device.
     
  3. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    The boat appears to have a plumb transom. It needs a transom with about 15 degrees of slope if an outboard is to be used. As Par says it is absurdly heavy. You must have used a powerful (heavy )engine in order to have experienced skidding. A large engine on a small boat, particularly this boat, is potentially dangerous. The presence of handles on the transom is a puzzlement. Who could lift that end of an eight hundred pound boat?

    Do not waste time or money on this structure as a floating object.. Your back yard appears to be a pleasant place. Dig a hole deep enough to bury the boat almost up to the gunwales. Fill it with water, perhaps a few stones, perhaps some small fish or plants. Use a small electric pump to create a waterfall over the stones. The sound is quite soothing to most people. I am not intending to insult you with this suggestion, nor am I intentionally being a smart ***. I am merely thinking of making good use of the boat like structure. Do not use this boat as a boat. Please accept my apologies for condemming it.
     
  4. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    800lbs for a boat that size... 400lb is already heavy... Makes a good bomb shelter.... Are you sure 800lb or is that a guess? 800 pounds means it can't be moved by normal methods...
     
  5. ancient kayaker
    Joined: Aug 2006
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    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    The problem seems to be, it's a barge. Despite the weight, with that area and almost flat bottom it probably has very little draft, which may be why it cannot grip the water. I imagine if it is down at the stern due to motor weight it would be hard to turn.

    However, before abandoning it, I would try a skeg per PAR's post with a lighter motor, also move forward to bring the bow down, using a tiller extension. Whatever you do, don't take it out to sea!
     
  6. thudpucker
    Joined: Jul 2007
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    Location: Al.

    thudpucker Senior Member

    And no mention of the trapped areas where the wood is going to rot on the inside of those Box's that are the sides.
     
  7. Rangerspeedboat
    Joined: Apr 2009
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    Location: Texas

    Rangerspeedboat Senior Member

    If that boat is 800lbs then its cast iron. Couldnt you add on an exterior keel piece?
     
  8. ancient kayaker
    Joined: Aug 2006
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    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Deducting an arbitrary 30% for frames and glass leaves enough weight for 3/4 ply inside and out. A bit over-built I would have to say, but feasible.
     

  9. Village_Idiot
    Joined: Oct 2007
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    Location: USA

    Village_Idiot Senior Member

    You may be able to use transom wedges to get the outboard into the proper position.

    No keel should be needed (most flat-bottomed boats have no keel). The chines are utilized for tracking the boat through the water. That boat should weigh no more than a couple hundred pounds and an oversized, overweight outboard would put very little chine in the water, hence the nervous feel to the vessel, not to mention the angle of the outboard is probably also forcing the bow up.

    I'm running a 26-foot boat with no keel - it actually has an anti-keel (pocket tunnel)! Tracking is accomplished with square chines and the outboard positioning.
     
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