keelmaterial for an alu sail boat!

Discussion in 'Materials' started by nukisen, Oct 25, 2009.

  1. nukisen
    Joined: Aug 2009
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    Location: Sweden

    nukisen Senior Member

    Hi all!
    I am planning to build a small aluminium sailor.
    though I do want the keel to have a higher dens. then aluminium.
    Of course I dont want the alu to bee corrogated by galvanic streams.

    Any suggestions of a good material! Not to expensive of course.
    The keel is still under design and should be a little deeper and a little bit shorter. The same opt. with the rudder.
    The data in the pdf file isn´t correct.
     

    Attached Files:

  2. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    Have you done any calc's, to confirm that you actually need a higher density material, for your righting moments?
     
  3. nukisen
    Joined: Aug 2009
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    nukisen Senior Member

    Yes i do have a righting moment of about 0.47 knewton at 60 degrees. And i am not sure how much a sail does press the boat at the side. I do have a vert cog about 0.45 with myself placed on the durk. I am sure that you meant the boat boat to be as light as possible. And the hull is about 20kilos at the moment. If I do use Alu. The vertical Km is about 0.67meters above lowest point at bottom (without keel inkluded).
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    A lead filled aluminum keel can work. You can cast the lead to the shape of the keel and set it in epoxy.
     
  5. nukisen
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    nukisen Senior Member

    Yes Gonzo!

    Actually I did have this in my mind. But I wasn´t sure about the galvanic. But you mean this wouldn´t bee any problem to corrugating the alu in salt water.
    Of course I will use alu Aw 5754 wich is saltwater resistant.
     
  6. nukisen
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    nukisen Senior Member

    Ad Hoc!
    I also have to calculate the sail before I make the boat heavyer.
    thx!
    Janne
     
  7. gonzo
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    gonzo Senior Member

    The lead and aluminum will not touch if the lead is encapsulated in epoxy
     

  8. nukisen
    Joined: Aug 2009
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    nukisen Senior Member

    Ah oki!
    Then I can use any material as I want.
    :)
     
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