Swing Keel/leaded centerboard delaminating

Discussion in 'Metal Boat Building' started by seanseward, Mar 7, 2016.

  1. seanseward
    Joined: Dec 2013
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    Location: United States

    seanseward Junior Member

    Swing Keel/leaded centerboard delaminating
    I need some advice how to best clean and reconnect a leaded keel in which the lead on the top 2 ½” is separating/folding away from the aluminum alloy fin. What is a good way to eliminate remaining oxidation of lead and aluminum? (I have scraped out all the white crust and gook that has accumulated between the aluminum and the lead, but there is still a film and remaining tiny pockets) What is the best way to “glue” lead back to aluminum alloy fin? A primer and then epoxy? Should I consider melting the lead back to the fin? Has anyone ever done such a thing?
    My plan:
    First, I believe that the keel is structurally sound; only the top 2”-3” of lead has delaminated from the aluminum. My basic plan so far is just to find some sort of anti-rust like primer to stop any further oxidation and then epoxy the lead back to the aluminum; (squishing it back together with c clamps and the like). I would fill in any cracks with epoxy and filler and grind back excess lead if it does not return to original width dimensions. I will enclose the finished body in a membrane of fiberglass protecting the body from salt water and oxidation. Is this a good plan? Should I consider torching the lead to melt it back into proper position? Any other great ideas?
    Details of boat, keel and cause of problem:
    Boat and keel: this is a Newport Neptune 16 with a swing keel. The keel has 200 lbs of lead set onto a approx. 4 foot ½” x 14” aluminum centerboard (see photos below which show a sample swing keel and shows how the lead is attached to the fin; in the second foto, the keel is broken and shows only the upper section of the lead and how it was attached to the fin; THIS IS NOT MY KEEL).
    Cause of problem: I messed up the keel when I repositioned the keel in the trunk by using a higher eye hole on the swivel axis of the swing keel and I did not reset the crib of the trailer to properly give space for the new position of the keel. The result was a boat sitting on the trailer with all rear weight resting on the centerboard. The wood ribs on the trailer were not raised enough to carry the boat and the hull rested on and squished/sandwiched the top 2” of lead on the keel. I have since changed the holding of the boat which allows the boat to properly rest on the trailer ribs…that problem solved.


    THIS IS NOT MY KEEL!
     

    Attached Files:

  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Hit the aluminum with a grinder, belt sander, DA or whatever, with an aggressive grit (40 or less). This will remove the corrosion and provide mechanical "tooth" to the repair area. As soon as the aluminum is roughed up, wipe dry and coat with straight epoxy. Next use a wire wheel running slow on a drill or grinder and scruff the crap out of the lead, with the same intention, cleaning and providing a good tooth to the surface. Again, immediately apply straight epoxy to the led. Lastly mix up a thickened batch of goo, using milled fibers and/or cotton flock (West system 403) and enough silica to prevent the goo from sagging or running out of the joint.

    Use only enough clamping pressure to insure the goo has good surface contact and oozes out slightly all around. Don't over squeeze the joint. When all this cures, it can be ground back to shape.
     
  3. seanseward
    Joined: Dec 2013
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    seanseward Junior Member

    Par,
    thank you for the advice. There are sections of the crevices that I will be able to ruff clean, but other crevices are very narrow and difficult to access. I guess that I need some kind of rotating bristled thing (with 3" bristles) to dig into the narrow crevices to clean it up.

    The rest of your advice sounds easy. thank you very much for the advice. it follows other general statements made by others but you give the detail that I need to properly understand the steps and method.

    Thank you,
    Sean
     
  4. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    You don't have to get every nook and cranny, though the more the better. A rotary wire brush works well as does a flap wheel. Just make sure you seal it all up good with goo, when it goes back together, so future corrosion will be avoided, in spite of a few areas that don't have a good grip.
     

  5. truewind
    Joined: Aug 2013
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    Location: USA

    truewind New Member

    I have a similar problem. Did your repair work and has it held up over the years?
     
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