Hanging epoxy reinforced rope as hull form "wireframe"

Discussion in 'Boatbuilding' started by John Smithson, Aug 23, 2021.

  1. John Smithson
    Joined: Aug 2021
    Posts: 28
    Likes: 3, Points: 3
    Location: Kansas

    John Smithson Junior Member

    ((Disclaimer: This is likely a bad idea))

    I've been following Sven Yrvind for a bit and the scrappy shop builds he does. Very much figuring it out as he goes and he gets the job done.

    Here I noticed he talks about using polyester rope saturated with epoxy TEXTILE HARDWARE AND A NUT https://www.yrvind.com/textile-hardware-and-a-nut/ , he has also mentioned using the same method as the hand holds in his latest ship. Just dipped rope and slapped up there.

    So, got me thinking, would it be possible to make a "spiderweb" mold for a hull (or other parts) using this same idea? Basically string the rope to get hull curves, then saturate them with epoxy... come back later and you have a stiff wireframe to work with.

    After that my best guess would be attaching cheap film (garbage bags even?) to the under side, then pouring in expanding foam to fill the cavities between the ropes sections (web it out so they are a square foot or something of that sort).

    Then you have a foam core in the shape of your hull you can carefully sand down and glass.

    Maybe if you did it in sections for more structural support as you went?

    Is this the proper way to do things? Definitely not.

    But maybe it would work? (big maybe)
  2. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,039, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    String rope around what ? Bulkhead frames ? Rope is not going to take up a smooth curve doing that .
    fallguy likes this.
  3. fallguy
    Joined: Dec 2016
    Posts: 7,408
    Likes: 1,590, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Mr E wins a prize. The problem is the rope still needs a former and so is ultimately useless.

    However an epoxied rope of fiberglass is something I have to do in the next month on a project of mine where my core got too small and the laminate won't stay on. So rope has a place and epoxied rope as well.

    I saw a guy build a beautiful rub rail from 1.75" rope he epoxied and screwed to his hull.

    In the end, the rope is still a beam for loading in your idea and not very strong versus a plywood frame.
  4. gonzo
    Joined: Aug 2002
    Posts: 16,575
    Likes: 1,558, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    It is an expensive and heavy method to build a hull. If you are using foam, buy foam in sheets for the core. Foam poured over or between garbage bags will create huge lumps of expensive foam.
  5. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,039, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    A more professional way would be something like C-Flex, but that seems a bit out of fashion these days
  6. DCockey
    Joined: Oct 2009
    Posts: 5,214
    Likes: 612, Points: 113, Legacy Rep: 1485
    Location: Midcoast Maine

    DCockey Senior Member

    Platt Monfort invented his Geodesic AiroLITE construction methods for canoes and very small boats in the eary 1980's. It uses a network of Kevlar cord over wood longitudinals, covered with heat-shrink Dacron fabric. The Kevlar cord provides support for the fabric by deforming in a cantenary curve in tension, not by bending stiffness. Thousands, possibly tens of thousands canoes and very small boats have been built using this method.
    Geodesic AiroLITE Boats - ultra lightweight SOF canoes and boats; plans, projects and tutorials http://gaboats.com/
    fallguy likes this.

  7. kapnD
    Joined: Jan 2003
    Posts: 1,195
    Likes: 331, Points: 83, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    I’m often drawing things out on the shop floor to get a full size perspective of whatever I’m doing.
    You could layout your lines on the floor, wet out the rope (hopefully it’s compatible w/epoxy)
    And lay it along the lines to form frames or whatever parts.
    I’ve always wished there was a way to bend G-10!
    DogCavalry likes this.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.