Quik kids cat

Discussion in 'Boat Design' started by boatindad, Feb 13, 2014.

  1. boatindad
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    boatindad Junior Member

    How would splitting Bateau cheap canoe in half and making a small asymmetrical catamaran work? I bought the supplys today and figured i would ask before I start. thanks for any info.
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    Split lengthways or crossways ? :D Sorry, but I suspect you are better to start with a boat designed from scratch, to do what you have in mind.
     
  3. boatindad
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    boatindad Junior Member

    Lengthwise down the center creating two flat sides that are mounted facing out.
    Then sealing with a thin deck.
     
  4. Richard Woods
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    Richard Woods Woods Designs

    If you mean down the hull CL, so you have a flat inner hull side, then the biggest problem (out of many) will be that you won't have added any extra displacement. But you will have added a lot of weight to each hull. Probably at least 30%, based on surface area alone. And then you'll need to add in the weight of crossbeams, rudders and rig.

    I don't know anything about a "Bateau cheap canoe", but I doubt if it has the hull volume you will need to make a safe boat, never mind one that you are happy sailing

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  5. boatindad
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    boatindad Junior Member

    With akas atatched like a Wharram with rope
    I would like to power it with a traction kite.
     
  6. boatindad
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    boatindad Junior Member

    Hmm Does anyone know the displacement of a formula 12? Thats kind of what i am going for. It only needs to carry 300lbs max me and one kid at a time. thats 5 cuft plus 2.5 for the boat so 7.5 cuft. The boat will be 14ft long ( http://www.bateau2.com/free/cheapcanoe.htm) 1ft deep and tapering from an average of 13in wide to nothing, so if i divde the length in half and multiply 7ft * 13in * 12in I get 7.58333...cuft of volume*62lbs is 470lbs for one hull is that not enough?
     
  7. boatindad
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    boatindad Junior Member

    I was also thinking about changing the transom a bit .. not sure though I read it would reduce rocking.
     
  8. boatindad
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    boatindad Junior Member

    Richard your sight is great lots of awesome info.!.
     
  9. Petros
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    Petros Senior Member

    cutting a mono hull in half strikes me as a really bad idea. you would structally compromise the hulls, risk leaks, weak spots, etc.

    I would suggest use the materials you have to make a couple of out riggers and turn the hull into a trimaran. the outriggers can be about 8 ft long and only need to be about 10" deep and perhaps 8" wide. held in place with some 10 ft long 2x4 beams (or you can build some nice box beams). Put a trampoline deck between the beams, and you will have lots of room and carrying capacity, it will be very stable, and not risk having a weak main hull. to transport you just dismount the beams and floats, and store them in the main hull.
     
  10. upchurchmr
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    upchurchmr Senior Member

    If you compare your idea to a production boat - the Hobie 16 - you will have the flats on the wrong side of the hulls.

    Flat side goes out, to help it act like a centerboard - resisting the leeway.

    Since you found Richard's site, you ought to just pick out one of his small cats. Much better chance of success.
     
  11. boatindad
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    boatindad Junior Member

    There wont be any cutting I meant that in the design sense and i agree the flats go out I might not have stated that well. The cheap canoe (free plans) is a two sheet canoe by adding 2 more sheets ie outer hulls sides and sealed decks I hope to build a cheap cat, not trying to break records or be extreme. I just want to build, play with and teach my kids. My wife keeps wanting me to do sports with my boys and I'm not very sporty but I love to build.
     
  12. Richard Woods
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    Richard Woods Woods Designs

    I don't "do" imperial units very well, but I think you are using the total hull volume when you calculated it? A typical beach cat might draw 6in? and should have at least 4-6in of freeboard with both hulls in the water

    I assume you are already a sailor? Even if you are using a free set of plans as a starting point, you are basically designing the boat your children will be sailing on. I'll let others comment on the wisdom of that. I cannot comment too much as you will have seen from my biography that my father built me a small catamaran for me to sail. But I never did so in more than 2 ft of water and I was always attached to him with a long painter

    Richard Woods
     
  13. boatindad
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    boatindad Junior Member

    Yes that is the whole volume of one hull. I am not a sailor I have never been. There is a lake near our home "Alum Creek" it has a beach area I was thinking of having the children (5) play on the beach and swim while I give them rides on the boat taking turns of course. We do kayak and all have life jackets. About ten years ago I built a one sheet dingy stitch and glue it was fun to build and simple I wanted to expand on that experience. Do your think my idea is unsafe. If so what could i do to remedy that. They are all good swimmers.
     
  14. Petros
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    Petros Senior Member

    I would not use modified mono-hull plans to build a catamaran, seems really foolish and a really bad idea. There are lots of proven small cat plans out there for little to no money. Just look for them.

    You might consider these old catamaran plans for free, once published in a magazine, designed to be built with hardware store type materials so it will be inexpensive to make (you can update the materials and hardware details if you choose). It would make a great first kids boat, no dagger boards but uses asymmetric hull shape much like a Hobie 14, made of plywood, which you can just paint, or glass over as you choose.

    http://svensons.com/boat/?p=SailBoats/Hobby_Kat



    here are some good modern plywood cat designs, low priced plans for $50-90:


    http://www.sailingcatamarans.com/index.php/designs/1-beach-cats-and-dinghies-/5-pixie-14

    http://www.boatdesigns.com/12-L-Gato-symmetrical-hull-catamaran/products/455/

    http://www.duckworksbbs.com/plans/woods/pixie/index.htm

    http://www.duckworksbbs.com/plans/dix/oppikat/index.htm
     

  15. messabout
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    messabout Senior Member

    Adding fuel to the naysayers: A 12 foot cat is not big enough for a 300 pound occupancy. If you put enough sail on it to go, even modestly, you will be dealing with lee bow bury. Not good, nor safe for beginner sailors.

    With apologies to Richard Wood, Why do you want a cat? A competantly designed, simple, 12 to 14 foot monohull will be more comfortable and safer. On top of that the boat will row decently..........do teach the kids to row. There is hidden pleasure and satisfaction in that activity. It'll also be a suitable fishing platform and might even have a modicum of market value when you are through with it. None of that is so with the split canoe catamaran.

    Think of a competently designed flat bottommed skiff, stitch and glue, easy and cheap to build, practical boat. There are hundreds of plan sets out there, from acknowledged professionals, for such a boat, the cost of the plans is modest. Make certain that the boat is designed for sail or row and not for mechanical power.

    Some of the plans, as published in Popular Mechanics, and other old magazines, are satisfactory, while many of them are dogs. Get the plans from a pro, not a magazine.
     
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