Converting a Rowboat to a sailing dinghy

Discussion in 'Fiberglass and Composite Boat Building' started by Oscar1, Aug 21, 2024.

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Leeboard or Centerboard? Or both?

  1. Only Leeboards

    1 vote(s)
    50.0%
  2. Only Centerboard

    0 vote(s)
    0.0%
  3. Both

    1 vote(s)
    50.0%
  1. Oscar1
    Joined: Aug 2024
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    Location: Denmark

    Oscar1 Junior Member

    Hello,
    i just bought a 10 ft /3 m dinghy that was used for rowing before. It is made of glasfiber. It has a beam of 140 cm and a height of 40 cm. It has no centerboard or keel and i think it weighs around 100-200kg.
    I want to convert it to a sailing dinghy that could sail in light wind near in coastal regions.

    I was thinking about using leeboards as opposed to installing a centerboard/daggerboard, however im unsure if that would even provide any sort of stability. I would like to only use leeboards as if i can avoid cutting a hole in the boat for the centerboard would be nice. However i will still have to repair some small holes with glasfiber and epoxy or polyester.

    Any response would be appreciated as i am kind of conflicted about how to continue on this.
    Also tips or recomndations on what to do about other things i haven't thought of would be nice.

    Best regards Oscar :D

    I will send pictures soon.
     
  2. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    For a small boat it is best to forget about the notion of any kind of board adding stability.The need is for some kind of surface(s) to resist leeway and whatever choice is made will need to built sufficiently strong to resist the force that the rig is capable of generating.Without knowing what kind of boatbuilding experience can be applied to the project it is difficult to make precise recommendations.Pictures may be useful
     
    Tomsboatshed likes this.
  3. seasquirt
    Joined: Dec 2015
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    Location: South Australia

    seasquirt Senior Member

    Hi Oscar1, keep the rowing aspect workable, and look at a balanced lug sail rig, which is very simple and easily installed in most cases. Lee boards will be OK, you can use one on a tether, swapping sides after tacking. 100 - 200 Kg is very heavy for a dinghy and it won't be fast, but its weight, and a lee board should give it some stability. On my dinghy I made 2 supports at stern and front deck to hold the mast, boom, and yard overhead while rowing, to get under low bridges, and make way in calms. Look for second hand rudder, mast, and boom from eg. a Mirror dinghy or Heron dinghy, or similar 10 - 12 foot long sailing dinghy. You may even adapt a complete rig and sail setup, except for complications arising from using lee boards. Don't spend any big money, do it cheap, and have fun. Make your trailer as easy to launch and retrieve as possible so you don't ruin your back with such a heavy boat.
     
  4. Oscar1
    Joined: Aug 2024
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    Location: Denmark

    Oscar1 Junior Member

    Here is images, i removed rooten wooden plancks and have cleaned it up
     
  5. Oscar1
    Joined: Aug 2024
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    Location: Denmark

    Oscar1 Junior Member

    Hello, i sent pictures in the thread, Thanks for your response, i dont have any boat building experince really, im just currently reading a lot of books and doing online research on the matter. I also intend to do some stability calculations before i add the rig.
     
  6. Oscar1
    Joined: Aug 2024
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    Location: Denmark

    Oscar1 Junior Member

    Thanks for your response, i will certainly look into lug sails, i am also trying to get most of the stuff second hand. I might look into keeping the rowing part aswell, i also thought about using a Yuloh oar for sculling or something as not to have big oars taking up too much space. I also sent pictures in thread if you want to have a look, i will most likely give it a new layer of paint on bottom. I worry a bit about it capsizing though due to the fact it is quite flat on the bottom, however i will have to test in safe waters. Thanks.
     
  7. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    That is not a rowboat, but a poweboat. It will be a terrible sailboat. The wide stern and flat buttocks are designed to plane.
     
  8. wet feet
    Joined: Nov 2004
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    Location: East Anglia,England

    wet feet Senior Member

    I wouldn't recommend getting too bogged down in stability calculations,other than as an exercise.For most dinghies there is an easy remedy in the muscles of the sailor.Just don't get too extreme with the rig.[​IMG]
     
  9. Oscar1
    Joined: Aug 2024
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    Location: Denmark

    Oscar1 Junior Member

    The boat is quite flat on the bottom do you Think this Will be too Big a problem? I intend to use the boat in mild water and Wind conditions
     

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  10. wet feet
    Joined: Nov 2004
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    Location: East Anglia,England

    wet feet Senior Member

    Looking at those pictures,you are facing a lot of work and will arrive at a boat with sailing characteristics that won't be particularly good.Lots of wetted surface and no sign of the structure that would be needed to support a mast and sail.Unless there is a really good reason to do a lot of work on this specific hull I would recommend looking for an alternative starting point to achieve the best result for all the hours of work that would be needed.
     
    bajansailor and BlueBell like this.
  11. Oscar1
    Joined: Aug 2024
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    Location: Denmark

    Oscar1 Junior Member

    Thanks a lot, I will probably sell this one anyway and find a more suitable one, is a normal with a more round or v shaped bottom better?
     
  12. Milehog
    Joined: Aug 2006
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    Milehog Clever Quip

    You are indeed better off to keep looking.
    Take some time and learn the differences between displacement and planing hulls.
    For example, a displacement hull has a lot of drag at sailing and rowing speeds. A lot of small planing hulls, like the one you showed, are sold or rented as row boats.
     
    bajansailor likes this.

  13. seasquirt
    Joined: Dec 2015
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    Location: South Australia

    seasquirt Senior Member

    If you're near the coast, go into a sailing club with dinghies, ask questions, look at photos, the people there will tell you heaps of info, and they may even have, or know of small second hand boats for sale needing little work, almost ready to go, and they will take you for a sail, teach you how, and talk your ears off if you want to listen. If you join a sailing club, often they have club boats you can use for free on race days, or be a crew for another sailor and you will learn many practical skills. It's fun and very sociable usually. Yacht clubs are always looking for new members, even just to help around the club, in the rescue boats, even behind the bar, where the biggest stories are re-told bigger each time. Just ask.
     
    bajansailor likes this.
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