Skin-On-Frame + Power

Discussion in 'Boat Design' started by rgardn12, Mar 16, 2010.

  1. rgardn12
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    rgardn12 Junior Member

    I have recently been contemplating building a Skin-on-Frame kayak but I have never owned one and I am quite intimidated by the thought of the "Roll"... thus I resigned to the idea of a canoe to paddle around the local lake. yet another thought occured to me when looking through some designs related to sailing, has anyone seen a design that would incorperate some kind of low power trolling motor?

    I've seen it done with cheap inflatable boats up to 10hp OUTBOARDS something I would advise, but its not my life or boat lol. my idea is that through simple modifications to a hull designed for use as a sailing hull, the use of a lightweight trolling motor could be used to propel the craft on days with little wind, while on good sailing days the mast could be put in place. my main concern is with the bouyance/weight distribution with the motor attached... as creating a solid stern to mount the motor to would doubtfully be hard to include on a skin on frame design.
     
  2. marshmat
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    marshmat Senior Member

    Small electric trolling motors are pretty light, and even on a small canoe, the weight of such a motor can be comfortably carried.

    The batteries needed to run it for a significant period of time, though, can quickly add up to a fair bit of weight.

    I hate to point out the obvious, but what's wrong with a paddle? Pound for pound, and dollar for dollar, a kayak paddle (and a ham sandwich for the captain) will probably get such a small boat farther, faster, than batteries and trolling motors.
     
  3. gonzo
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    gonzo Senior Member

    If you are willing to spend the money, they are electric motors with built in Lithium batteries that are quite light.
     
  4. rgardn12
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    rgardn12 Junior Member

    although I know paddling is an excellent mode of transportation... its more out of interest than sheer need. the more I think about the combined weight of batteries and motor I agree trolling motors for their weight are not the most efficient nor can I spend the money for the lithium batteries....

    it makes me wonder the estimated weight of a smaller 2 stroke outboard motor... and if it would be a viable option, I have seen (and personally know where I might get one very cheap) 2 and 3 hp motors that don't look very heavy at all, I am wondering if they might be more "Efficent" given the weight of standard batteries and the trolling motor itself? the newest 4-stroke 2hp honda motor is only 27 pounds... I can't imagine that being to hard to support, while the 5hp honda and 6hp yamaha both weight in at 60 lbs. what kind of modifications would need to be done to allow a 2hp motor to be mounted? or even a 5hp?
     
  5. gonzo
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    gonzo Senior Member

    Those small motors are fairly light. If you are designing for a motor, it is bette to have a wider stern
     
  6. rgardn12
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    rgardn12 Junior Member

    its is interesting I guess instead of really re-"Designing" a sailing hull... just out of curiosity I wonder how a skin-on-frame would do supporting a 2-5hp... and if it could be built to hold the forces of crossing others' wakes and chopping waters.

    can any of you guess suggest some kind of dimensional plans that could easily be converted from traditional to SOF design? after looking around I have something similar to https://www.boatdesigns.com/products.asp?dept=711 (as far as shape and size) I have no intentions on attempting to use the "view hole" it was just as similar to the picture in my brain as possible.
     
  7. gonzo
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    gonzo Senior Member

    Converting designs is usually more work than designing for the expected construction method.
     
  8. rgardn12
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    rgardn12 Junior Member

    are there any designs currently made for a lightweight outboard and SOF? I've done a little searching but can't find any good resources for that kind of powered craft.
     
  9. messabout
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    messabout Senior Member

    Quick question.......Why do you wish to use SOF for a powered boat?

    You can build with firm skin , maybe 4mm okumee, and the weight will not be much more than the SOF type. Rigid skin structures contribute to the stiffness of the boat which is a good idea for a powered vessel. Skin on frame boats , out of necessity, use a lot of complex framing to provide a base for the skin. Rigid skin boats need far less framing, which translates to less building labor, and they have cleaner interiors. Take a look at some of the Guillemot, Pygmy, or Chesapeake light craft catalogues. You might find something that will fill your wishes.
     

  10. rgardn12
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    rgardn12 Junior Member

    the idea originally came because I was looking to have an electric backup motor on a sailboat but once i saw how light 2hp motors were i thought it would be interesting to see if it had been done and how effective it was...

    however after doing some studys last night it seems to me that it would also be VERY difficult to the incorporate chines and certain angles while maintaining the strength of the inner ribs... so I tend to agree with your statement.
     
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