Rudder head blowout!

Discussion in 'Multihulls' started by paxfish, Jun 29, 2015.

  1. paxfish
    Joined: Dec 2014
    Posts: 85
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    Location: Southern Maryland

    paxfish Junior Member

    During a gybe yesterday on my cat at about 8 knots, I heard a POP and lost most of my steerage. We quickly got the motor going and dropped the sails. We anchored up in the lee of an island, secured the blade and motored home. We may have hit something - there has been a bit of debris out there this week due to big storms. Great! Another project!

    I'm guessing the lower gudgeon is designed to break before the rudder blade in the event of an impact.

    The rudder blade blew out the back of the lower gudgeon and twisted the upper gudgeon severely enough that I think I need to reglass it as well. The cheek was badly torn on one side. There are several pictures here: https://imgur.com/a/V0pZ4


    The rudder blade is undamaged. This is a Tennant Wildfire (GBE variant)

    The drawings call for 200 strands of gunstock for each gudgeon, 1135 triax for the cheeks and 3 layers of triax between the upper gudgeon and tiller.

    I need short term fix to get up and running for the long weekend coming up. A longer term fix can be discussed further down this thread. I'm not sure of the process to rebuild this thing, but am certainly willing to try. How would you tackle this?

    Here are a few pictures: https://imgur.com/a/V0pZ4

    [​IMG]
     
  2. rcnesneg
    Joined: Sep 2013
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    Location: Utah

    rcnesneg Senior Member

    How well does she sail on just one rudder? My experience is limited to small beach cats (up to 20 feet) and they all sail just fine on one rudder as long as you don't get the hull out of the water. I'm not sure there's a very good temporary solution to it besides just getting a working rudder on there on working gudgeons, which may require reglassing like you said.

    Good luck!
     
  3. paxfish
    Joined: Dec 2014
    Posts: 85
    Likes: 1, Points: 0, Legacy Rep: 17
    Location: Southern Maryland

    paxfish Junior Member

    Yeah - it sails Ok on one rudder. I'm sure glad I had redundancy though, and at some point I expect a hull will come out of the water!

    My current plan is to:
    1)Grind off the paint
    2) Wax the rudder blade, cover it in wax paper and slide it back into the rudder head to get everything lined up.
    3) Repair the cracks with epoxy and 404 filler.
    4) re-glass the Gudgeons.
    5) Cut away the thin cheek panels, and glass in new ones.
    6) Fair and paint.

    Anybody want to add/remove steps here?

    [​IMG]
     
  4. Tom.151
    Joined: Jul 2009
    Posts: 194
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    Location: New England, USA

    Tom.151 Senior Member

    That would work - probably permanently ;)
    Post up the results pics when you have them.

    Love that boat.

    Cheers,
    TomH

    PS -- maybe, before you destroy the evidence with a repair, try to confirm whether the current build was to the spec.
    In any case, I'd (re)build it to just what was there when it failed. It wold be hard to engineer it to fail in such a "convenient" way.
     
  5. catsketcher
    Joined: Mar 2006
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    Location: Australia

    catsketcher Senior Member

    Gday Pax

    Composite gudgeons are funny beasts. It is easiest to make them by wrapping uni thread from one side of the rudder box to the other but I think that is the wrong way. There is little strength to stop the gudgeon splitting like yours did.

    I had the same thing happen to my small cat when the rudder box got hit by a sailboard. Looking at it again I realised it was easy to split.

    On subsequent boxes I wrapped each thread around the composite tube, looping it around the tube each time it went around the front of the box. It looked messy but is very strong and you then fill it with filler and a cover of a piece of fabric.

    Then the unis are spread over the side of the box.

    Good luck with the repair

    Phil
     
  6. catsketcher
    Joined: Mar 2006
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    Location: Australia

    catsketcher Senior Member

    Here are some photos of the stitching holding the composite rudder tube on
     

    Attached Files:


  7. catsketcher
    Joined: Mar 2006
    Posts: 1,315
    Likes: 161, Points: 63, Legacy Rep: 790
    Location: Australia

    catsketcher Senior Member

    And one of the rudder boxes after fairing
     

    Attached Files:

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