Caravel planking

Discussion in 'Press Releases' started by JimHog, Oct 26, 2006.

  1. JimHog
    Joined: Oct 2006
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    JimHog New Member

    If I use this method of planking and use some "new" type caulking between planks...after I sand and seal or paint hull will the planks still swell when the boat is put in the water?(like in the older method of cotton caulking).I'm at he reading stage just getting information right now. Thanks
     
  2. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    If you doon't want it to swell you must either keep them completely dry or have quite thin planking and strong frames. It also depends on the type of wood you use. Racing sailboats used to be built of mahogany planking with no caulking, just a tiight fit or (later) glue. Sometimes the frames broke if the planking got too wet.
     
  3. PAR
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    PAR Yacht Designer/Builder

    Carvel planking requires a mechanical linkage between the planks. By this I mean the caulking forces the planks together, which makes them a homogonous whole, as if the boat was carved out of a solid chunk of wood. When a properly caulked hull gets wet, the moisture gain increases this pressure on the edges of the planks, making it tighter.

    No goo in a tube will provide this element of the structure. It can keep out water for a limited time (until the planks wiggle loose and spit out the goo), but the mechanical linkage must be there.

    If you have truly fine planking material and perfect bevels, you can forgo the caulk and edge set them. This relies entirely on moisture gain to make the hull drum tight. The plank fits must be perfect and the stock very stable, rift sawn material. As this style construction ages, it will leak, but when new it will look great with tight seams.

    There are a few different approaches to caulking carvel craft. Which method did you have in mind?
     
  4. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    It was popular to replace caulking on old fishing boats (turned into leisure crafts) with a strip of wood glued in. A circular saw with double blades was used to remove the caulking and make a slot between the planks. The problem was if you had some weak frames they would brake when the skin expanded.
     
  5. ancientmariner
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    ancientmariner Junior Member

    Of Course!

    wHEN WOOD GETS WET IT SWELLS, pERIOD. iTS A BOAT SO IT WILL GET WET.
     

  6. PAR
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    PAR Yacht Designer/Builder

    That's called wedge seaming and is one of the methods I mentioned. It's effective on trailer boats and above the LWL on moored craft. I wouldn't recommend it below the waterline on vessels that will spend the winter on the hard, drying out and on the hook or dock during season.
     
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