Add Centerboard to Shoal Draft Keel

Discussion in 'Boat Design' started by FirstLight, Oct 12, 2010.

  1. FirstLight
    Joined: Sep 2007
    Posts: 78
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    Location: North Carolina

    FirstLight Junior Member

    Hello All,

    We are looking at a boat that was designed for a shoal draft keel with a centerboard. For some reason, several of the boats that came out of the factory were built with a keel with the area for the centerboard founded with lead instead of the space for a board.

    I was wondering if anyone has heard of a way to retrofit away from this. Specifically, how to hog out a 4"wide x 14" deep by 36" long chunk of lead from the bottom off a keel. Building the board and fitting with a bearing would be no problem. Nor do I see drilling the hole for centerboard cable to be a problem. However, removeing the lead stumps me.

    I've heard of folks using a chainsaw to cut keels and unfortunately I've used a grinder on reshaping keels on star boats. However, hoggin out that much lead is something I'm not sure about.. Unless a chainsaw could be used to hog out material?? Sounds ugly and dangerous though.. But if it were to work, so be it??

    Any thought greatly appreciated.


  2. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    Very tedious. Also, you lose almost 900# of lead down low by my rough figuring.
    Drilling with self-feed augers comes to mind. Then cleaning up with a big slick. However, you might consider leeboards instead. Especially since you can move the leeboards fore or aft if you have to.
    Have you determined what's to be gained? A few points to windward, but a loss of speed with board down when off the wind. Less ballast to resist capsize. An above-waterline pendant exit hole, no doubt protruding into the cockpit or cabin.
    It may be that it was discovered that the shoal keel sufficed and did pretty well without the foil.
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    What make, model and year boat are we talking about?

    If the lead has a reasonable amount of antimony (2% - 5%) then it can be fairly easily machined, with well lubricated tools. I'd drill the corners and connect the "dots" with a wire saw or broken band saw blade.
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