Keel trailing edge Hunter 26.5

Discussion in 'Hydrodynamics and Aerodynamics' started by Chaos, Jul 23, 2020.

  1. Chaos
    Joined: Sep 2014
    Posts: 3
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Arkansas

    Chaos New Member

    I have finally purchased a trailer and have tackled the hideous job of stripping the gel coat due to the dreaded "pox". A typical problem of this era boat (1988 or so).
    I have discovered a rather odd shape to the trailing edge of the keel next to the hull. It is squared off and tapering down about 7 inches to the back edge of the main keel. The upper edge is about 1.2 inches wide. This does NOT look like a very good low drag configuration. My Momma taught me that all trailing edges should be 0.25 inches wide and squared to the chord.
    I intend to correct this as much as possible, depending on base material, etc.
    But, I am curious. Does anyone know of other keel designs as this? Is this a unique Hunter idea? Is there any hydrodynamic justification?
    Picture attached.
    Thanks, Ron Nash
     

    Attached Files:

  2. bajansailor
    Joined: Oct 2007
    Posts: 1,134
    Likes: 301, Points: 83, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Welcome to the Forum Ron.

    Do you have a fibreglass sump in the hull bottom, in the top section of the keel, or is it all bolted on keel right up to where the keel meets the hull?
    If there is a sump, approx how far down is the keel / hull joint?

    Re fairing this squared off trailing edge, are you planning on extending the chord aft some so that the aft end is tapered down to about 0.25" wide?

    I am thinking that if you are not a fanatical racer, and the boat sails reasonably well as is, I would be inclined to leave it alone.
     
  3. Chaos
    Joined: Sep 2014
    Posts: 3
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Arkansas

    Chaos New Member

    Bajan, Thanks for the reply. Yes, I plan to straighten it up the best I can. I'm too OCD for anything else. If it is not right, it just is not right no matter how you rationalize. (and yes, I race in PHRF, etc) I have not studied, measured the inside as yet. I am trying to get the gel coat off so it will start drying out (about 60% done). I hope I can get my 0.25 by taking material off, not adding to. But, depends on what is inside. I will follow up when I tackle the keel.
     

  4. Chaos
    Joined: Sep 2014
    Posts: 3
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Arkansas

    Chaos New Member

    OK, I have answered my own questions. This shape of the upper trailing edge of the keel is in the mold section of the hull. The wide section and high relief angles are to allow the section easier release from the mold. Nothing more than that. This is one of those compromise designs in production hulls. I plan to correct the shape the best I can depending on the inner material, depth of, etc. and by possible extension of the section (as Bajan suggested). There were plenty of ways Hunter could have designed the mold to avoid the problem. They could have used a removable plate (s) and/or loose pieces to allow release of the section. But, hey, too much trouble out on the production floor.
    Thanks, Ron
     
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