Repairing a cracked rudder support (skeg?)

Discussion in 'Fiberglass and Composite Boat Building' started by pmack, Jan 7, 2014.

  1. pmack
    Joined: Jan 2014
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Sydney

    pmack New Member

    Hey there,

    I'm not a sailor, yet alone a boat builder, but am at the sailing club here in Dakar Senegal waiting to hitch a ride across the Atlantic...

    Anyway a boat arrived here a few weeks ago on it's way from the Canary islands with some fairly serious damage, a wave hit the boat from the side during rough seas, and some time after it was noticed that the boat was leaking. The support for the rudder (skeg?) had cracked badly on both sides where it meets the hull. It sailed like this for probably a week with the pumps being enough to get the water out. Someone tried to temporarily repair it underwater in Morocco where they had no means to get the boat out of the water, unsuccessfully. They finally got the boat out of the water here, but from what i see the people here have little experience with fiber glass boat building, or at least with problems such as this one.

    The steel axle for the rudder was bent around 10 degrees where it meets the rudder. This has been bent back at a workshop elsewhere. The skeg was also deformed a simillar amount and has since had the fibre glass cut away, and now lightly re-patched.

    The captain wants to make it as strong as possible and has the idea of adding around 3 fabricated metal "L" brackets on each side, and then fibreglassing over that.

    I have no experience or knowledge with fiber glass, but at least with my engineering background, it has got me thinking about this. Would this work? My concern is that it is going to generate stress concentrators that will then cause the brackets to produce new cracks in the hull.

    Any feedback?

    Here's a pic of before they put the brackets on. They hope to be done in around 4-5 days. Things are slow of course in Africa.


    [​IMG]

    boat is a jeanneau sunshine-38
     
  2. Landlubber
    Joined: Jun 2007
    Posts: 2,640
    Likes: 123, Points: 0, Legacy Rep: 1802
    Location: Brisbane

    Landlubber Senior Member

    The repair of this sort of damage is not simply building up again as you see in the temp repair, the inside of the boat has been damaged too, as the skeg was built as part of a whole, not simply added later. The interior will need to be ground away and rebuilt and extended in width, then the outside can be ground away and extended in width as well. The outside is ground away till it gets to the new inside.
    Rudder bearing areas need to be treated the same as they will be stressed to the max to let the shaft bend as it did.
    You can use triax and straight rovings to form a spread (web) of strength on the inside, use csm between layers to get fill in.
     
  3. hoytedow
    Joined: Sep 2009
    Posts: 5,402
    Likes: 194, Points: 73, Legacy Rep: 2489
    Location: North of Cuba

    hoytedow Wood Butcher

    Along with what Landlubber said you might be better served by having a block of wood glassed into the area on each side until you reach a port with better repair services to re do it properly.
     

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