Foam Strip Plank Boatbuilding - John Lindahl

Discussion in 'Boatbuilding' started by DCockey, Apr 10, 2012.

  1. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    EPOXYWORKS Spring 2012, Number 34, has an three page article by John Lindahl on how he build Class A catamaran hulls with strip-planked foam covered inside and out with carbon cloth and epoxy. Result is a very light and stiff boat.

    Each hull is laid up in two halves. Lindahl uses a set of CNC cut female station molds at 6" increments. He cuts strips of foam with beads and coves (same shape as used for wood strip canoes). The inside of the station molds are then "planked" with the strips and a layer of carbon cloth and epoxy is applied inside the strips. The hull haves are removed from the mold stations and glued together. The outside is then covered with a layer cloth and epoxy.

    I've seen part of a hull and the workmanship is excellent. I assume it was vacuum bagged but Lindahl said he just "knows how to use a squeege".

    More details in the article (not yet posted on the EPOXYWORKS website) and on Lindahl's website.
  2. CatBuilder

    CatBuilder Previous Member

    Pretty standard way to build a catamaran. Exactly the same way I did it, except I only used strip planking where it was a tight radius. Thermoformed the rest.

    The bead and cove, IMO, is a huge waste of time. All you need to do is screw the full length strip planks down to your stations and bog in between them. Much faster way to do it and you get the same fairness and accuracy in the final product.

    Alternatively, you *really* have your heart set on locking the bead and coves together, you can order it pre-made from Gurit with a bead and cove on the edges of ready made planks.

    Here are a few pictures...

    Attached Files:

  3. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    Lindahl's boats are much smaller than yours. Raced by one person, 20 foot LOA, 7.6 ft or so beam, minimum boat weight of 165 lbs which he has to ballast to meet (hulls are a small fraction of the weight). More like a pair of sea kayaks than a cat with passenger accomodations. He does vary the width of the strips - wider where there is less curvature.
  4. CatBuilder

    CatBuilder Previous Member

    I know. Took a look at his site. Looks like a *very* fun boat! :D

  5. Herman
    Joined: Oct 2004
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    Location: The Netherlands

    Herman Senior Member

    Also do a search on "Andre Bilodeau" who wrote a complete book on the subject.

    Is Andre still alive? His Email is not functioning. I still have a couple of his books though.
    Last edited: Apr 11, 2012
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