Expanded metal core with fiberglass

Discussion in 'Materials' started by Floatything, Dec 4, 2019.

  1. Floatything
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    Floatything Junior Member

    Anyone have any experience with this? Steel is heavy so this would help save weight. Wrap the expanded steel with fiberglass/epoxy to complete the hull. Inside and outside would be glassed so it would be sticking to the steel and to itself. Maybe solid steel below the waterline? The framing would have to be reinforced but overall I think it would work for a 1-off sailboat.

    I've done some small test pieces and it looks promising. I not sure how well it would work on say a 30-40 foot sailboat or larger.

    Thoughts please.
     
  2. ondarvr
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    ondarvr Senior Member

    What properties do you expect to enhance with this combination?
     
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    Expanded steel in what form ?
     
  4. Floatything
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    Floatything Junior Member

    It’s more about saving weight and building ease/time than enhancing anything.
     
  5. Floatything
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    Floatything Junior Member

  6. Mr Efficiency
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    Mr Efficiency Senior Member

    How are you going to get it to follow compound curvature ? A blow-torch ?
     
  7. rxcomposite
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    rxcomposite Senior Member

    you mean this one?
     

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  8. Barry
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    Barry Senior Member

    Google Boat Building In C Flex glass if you are trying to save some labor in frame building if that is what you are trying to do
     
  9. gonzo
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    gonzo Senior Member

    It will be heavier. If you want light weight, a foam or balsa core is the way to go.
     
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    I don't see much hope, for this idea, the function of a core is to keep the two skins apart, so that the tensile strength of the skins can be exploited, not so much as the structural strength component. It seems like an all-round nightmare to me !
     
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  11. gonzo
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    gonzo Senior Member

    Also, if there ever is any water intrusion, the whole thing will rust and come apart.
     
  12. messabout
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    messabout Senior Member

    The structure will be neither stronger nor more durable. It will also be heavier. A structure with a light weight core that separates the inner and outer skin, as Mr E has suggested, will be much stiffer.
     
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  13. fallguy
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    fallguy Senior Member

    Last edited: Dec 5, 2019
  14. JSL
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    JSL Senior Member

    valid remarks.
    - You could also add the electrical aspect. Steel conducts, frp doesn't. A lightening strike or short circuit could be 'interesting'... your boat might be like a large capacitor.
    - Some years ago I saw an electrical 'contact' from 14,000V overhead power lines on a 40' racing sailboat (nicknamed 'Sparky). Looked like minimal damage at first but with carbon fibre reinforcement, testing indicated that the entire boat's structure & outfitting was compromised.
     

  15. fredrosse
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    fredrosse USACE Steam

    Galvanized steel expanded metal we found to be ideal when making ferrocement hulls, compound curves were easily possible. Seems like what you are proposing is to make a hull with the expanded metal only to hold the fiberglass and epoxy in place during construction. Probably would work OK, but as others have indicated, strip planking with fiberglass/epoxy skins is a better option.
     
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