"PUTZ" Floats!

Discussion in 'Wooden Boat Building and Restoration' started by LP, Dec 6, 2009.

  1. LP
    Joined: Jul 2005
    Posts: 1,413
    Likes: 57, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Putz for putzing around the harbor, bay or what-ever other protected water to want to explore.

    It's just a little one-sheet ply boat that I've developed. A 7 1/2' kayak made with 1/8" ply thats SandG'ed. Sea trials went expected. I wanted to to see if I could design a floatable "one-sheeter."

    I have to confess that I didn't run stability numbers until after I started building. Oops. None the less, it was showing positive stability through a range of heel angles. However, I dug into the design further and have improved stability five fold. It was a fun little development. As work progressed, I found myself reducing structures and glass lay-ups as the strength of my little boat revealed itself. Currently, its 1/8" ply with 6 oz. exterior sheathing on the top-sides and upper strakes and 8 oz. sheathing on the bottom and 1st strake inside and out and 6 oz. inside on strake 2 (the vertical side strake). The next one will all be sheathed in 6 oz. cloth with maybe second layer on the exterior bottom for abrasion resistance.

    This was my own little dabble into an SandG design and build as I have never built with SandG. I've always been intrigued with the idea of taking a series of flat panels, connecting their edge and getting a boat. It was also a trial with picking scantlings and sheathings for the design. The strength of the hull is amazing. I can stand my full weight on the cockpit ring with out any flexure in the hull.

    I was surprised at how little it took to make Putz go. I've rented various kayaks before and was always surprised at how sluggish they were. This little one glides almost effortlessly.

    The wife's ride was more stable than mine and she ventured further out than I dared. Developements will continue. I think later versions will prove to be a comfortable little kayak that will fit in a 6 1/2' pick-up bed and only weighs 25 lbs. More to come. Waterwings are to be added to the prototype to bring the stability numbers up to the newer version.
     

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  2. LP
    Joined: Jul 2005
    Posts: 1,413
    Likes: 57, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    PUTZ with wings.

    Day two of sea trials. 2" per side of foam at midship tapering to nothing at the ends was added and glassed over. The stability improvement was great and so I feel that the design idea has been proven. More days at the drawing board has also yielded further improvements in Putz's stability and the whole one sheet of ply idea.

    As for the prototype, a couple more layers of glass over the foam and a little bit of paint and varnish and we'll call it good. The water wings added several pounds, but it was cheaper and quicker than building from scratch and provided for the stability check that I needed.

    I'm looking at designing a harness/sling so that it could be carried on my back for those excursions up into mountain lakes. Hmmm...

    All-in-all, there were no surprises during sea trial on Putz. The stability issues were expected and correction made. Better than that, the kayak floated on it's lines with no trim errors.
     

    Attached Files:

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