hull distorted, repair options

Discussion in 'Boat Design' started by Limpet, Aug 7, 2016.

  1. Limpet
    Joined: Aug 2016
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: South Africa

    Limpet Limpet


    I am busy replacing the deck in my 1980's Robbiduck 4.2m semi rigid and have come up against a problem which confounds me.The previous deck was rotten and the foam in the hull was waterlogged. These have both been removed.

    When on flat water the boat listed quite noticeably to the port. This did bother me and I suspected it was water logged foam creating the imbalance. In addition, the console had been installed skew by whoever did this and I suspect it was done to try to balance the boat. I also thought that the skew console was contributing to the listing. I tried trimming the boat with weight (fuel, battery, etc) in the console, but could never get this right. When trimming with people it worked to a degree, but didn't assist the ride.

    SO during my replacement of the deck, the idea was to also correct this.

    When measuring the "stringers" for preparing to cut stringers and bulkheads for hatches and deck support, it became apparent that the port side inner mold facing (I don't know the name for it) has expanded out and the distance from the center line is not the same as the starboard side by about 30mm at the widest point of the problem area. See the attached sketch.

    I have not removed the pontoons from the boat. The questions I have are:
    Is it possible that the original join of the top mold to the bottom hull mold has failed and the edges are overlapping resulting in the internal mold distortion?
    If so; is this repairable?
    Is it worth repairing? Or can I just install the deck slightly wider in the area.
    What would it cost to remove the pontoons and replace after repair work? The pontoons are still good.

    Advice would be appreciated.

    Attached Files:

  2. BertKu
    Joined: May 2009
    Posts: 2,521
    Likes: 47, Points: 58, Legacy Rep: 223
    Location: South Africa Little Brak River

    BertKu Senior Member

    When I had something similar, I used 3 x 6 ton jacks, a very thick concrete wall, to lean the other side of the boat against, some wooden studs from the mine, fiber glass and I was able to do the correction. I have no idea whether something like that could solve your problem. The drawing is upside down and I have not yet been able to load it on a laptop. Bert
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