fiberglass boat design idea

Discussion in 'Boat Design' started by shodo, Jul 9, 2014.

  1. shodo
    Joined: Jul 2014
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    shodo New Member

    Hi; I have received a batch of fiberglass rebar ranging from 1/8 in - 1 in. Sizes are 1/8,1/4, 3/8, 1/2, 5/8, 3/4, and 1 in.
    Question is
    1.do you think these rebar rods will make good ribs for a kayak/canoe doing stitch and glue plans..
    2. do you think forms are needed, as these rebar rods are easy to bend and tieing will hold them till they are fiberglassed in.

    3. any ideas and suggestions are welcome.

    Thank you for your time.
    Sam
     
  2. upchurchmr
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    upchurchmr Senior Member

    You don't need ribs in stitch and glue, at least in a kayak sized boat.
    Glass is heavy and not very stiff in bending for the same weight, if you do need ribs.
     
  3. gonzo
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    gonzo Senior Member

    That is the ideal material for a skin on frame kayak or canoe.
     
  4. upchurchmr
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    upchurchmr Senior Member

    G10????

    Gonzo, what did you mean?
     
  5. gonzo
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    gonzo Senior Member

    He has thin long fiberglass rods. He can build three or four plywood bulkheads, spring the rods around them and cover them with fabric or plastic. Voila, a skin on frame boat.
     
  6. rwatson
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    rwatson Senior Member

    Depends how long they are too. Even two bars joined with aluminum pipe, lfor stringers would be usable.

    You have the potential to build a dismantlementable canoe, like the Folboats of years ago, that used wooden doweling to make a collapsible frame.
     
  7. upchurchmr
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    upchurchmr Senior Member

    OK, I finally get it.
    Weight one and compare it to a typical SOF stringer. 3/4" square is typical out of western red cedar.
    Then bend a piece of the fiberglass next to the piece of cedar and see which one is stiffest.

    Of course if the glass is not close to 3/4" square it will be more flexible and probably heavier.

    For a SOF the stringers are the only thing that keeps the boat from bending (OK the skin helps a very little).
    You really need the same stiffness as the Cedar, and don't forget that more of the bending resistance comes from the gunwale 1 1/2" x 3/4"

    You certainly can build the boat, you might not like it.

    If you do the test please let us all know what happened- I'd like you to prove me wrong so we have another option.
     
  8. bpw
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    bpw Senior Member

    That must be why no one uses it.

    Fiberglass is super heavy for bending resistance compared to wood or aluminum pipe, and kayaks don't like being overly flexy or any heavier than necessary. With the proper materials being so cheap I don't see any reason to cmopromise.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    Reminds me of the old original fibreglass fishing rods. They were heavy, and quickly abandoned for hollow glass.
     
  10. rwatson
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    rwatson Senior Member

    Yes, timber would perform much, much better for lighter weight and stiffness.

    That's probably why the OP has ended up with them - probably cheaply.
     
  11. gonzo
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    gonzo Senior Member

    Materials don't come cheaper than free. I would build myself a kayak with them.
     
  12. rwatson
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    rwatson Senior Member

    hmmmm - with all the effort to make them work, cover them, and end up with a heavier than needed craft, it would be a close call for me.
     
  13. Mr Efficiency
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    Mr Efficiency Senior Member

    I would say a waste of time. You can't bend fibreglass rods into a shape you want and have them retain that shape, freestanding. I can't see any application here.
     
  14. SamSam
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    SamSam Senior Member

    They are very rough, as they should be for rebar. I would imagine they would have to be smoothed down so they wouldn't eat up a skin.
     

  15. bpw
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    bpw Senior Member

    Spending $300 dollars to build a crappy boat doesn't make sense when it would only cost $400 to build a good one. He is going to need quite a few more things than just fiberglass rod to build a boat. The framing material for a kayak really doesn't cost much at all.

    You wouldn't build a sailboat hull out of fiberboard just because it was free would you?
     
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