Rudder renovation

 

Since we bought Anna, we have noticed a ‘clunk’ from the rudder, indicating some play between the gudgeons and pins. During the summer of 2015, the sound seemingly increased and we decided to do something about it. Hindsight being 20/20, we may not have done it yet, had we known that the play was only 1.5-2 mm.

The rudder is fixed to the skeg/hull in two places. Each place is made up of two gudgeons, one fitted to the skeg and rudder respectively, and a 35mm pin joining the two gudgeons. There is also a rudder post fixed to the top of the rudder (the rudder post has a cone with pin slot and thread and is fixed into the rudder fitting by a nut). All items are bronze. All fittings are puttied over.

This is how we went about fitting new pins:

  1. Remove putty covering the two gudgeons on the rudder. Do not remove putty from rudder outside the gudgeons.
    Lessons learned: We also removed the putty from the gudgeons on the skeg; not needed. We used a chisel to remove the putty; better cut with a small (Dremel?) disc around the gudgeon first.
  2. Remove putty covering the rudder post nut.
    Lesson learned: We used a chisel; better use a small grinding disc first to save on putty later.
  3. Remove all fittings from rudder post (quadrant, stuffing box nut etc) inside the aft cabin.
    Lesson learned: We removed the grease pipe from the stuffing box (it had become clogged with solidified grease) to fill new grease. The nut is made of brass and had dezincified; it split when refitting.
  4. Loosen nut at bottom of rudder post. Using wedges (one from each side), push the rudder post up into the rudder fitting. Remove nut. Continue pushing rudder post up into the hull. We used short (ca 25mm long) pieces of wood which fit into the upper rudder fitting, adding a piece at a time, to drive the post up, first using the wedges and later a small crow bar.
    Since we had difficulties getting the rudder post cone to release from the rudder fitting, we drilled a hole from the front of the rudder, starting about 25 cm below the nut, angling up to meet the bottom of the post (where the nut sits). Into this hole, we inserted a steel rod allowing us to knock the post up to release from the fitting, using a small sledge hammer.
  5. Remove the three rivets fixing each of the two gudgeons to the rudder.
  6. Slide the rudder out from the gudgeons. We used a car jack to support the rudder when doing this; it weighs about 60 kgs.
  7. Remove pins and two rudder gudgeons (the two gudgeons affixed to the skeg can be left in place).
  8. We fitted slightly oversized pins, machined from a 37mm bronze axle. The holes in the gudgeons were close to perfectly round, but were slightly wider at the ends, making it necessary to machine the holes somewhat. The holes in the gudgeons on the skeg were machined using a rotary file/sander.
  9. When re-assembling, we fitted a nylon washer (thanks to www.profilplast.se) in between each set of gudgeons. We used bolts instead of rivets. To be able to press the rudder into the gudgeons (it’s a tight fit with a lot of friction), we built a simple cradle to allow pressing the rudder and skeg together (at first attempt, without the cradle, the angle of the skeg made the nylon webbing slide down).

All in all, you could probably continue with a lot more play in the gudgeons than we had. For us, the main deciding factor was the ‘clunk’ noise each time a quartering wave caught up with us and the impression that the clunk was getting louder during the previous season.

Total time taken was roughly 25 hours. With a proper workshop and better prior information, you should be able to cut this in half, obviously spread over a few days, allowing for epoxy putty and paint to harden.

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Rudder post has a cone and pin slot and is fixed into upper rudder fitting with a nut. The pin is spot welded (soldered?) into the rudder fitting.

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Rudder post nut was easy to unscrew

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Getting rudder post up out of the fitting was also easy, once you got it moving the first few millimeters…

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We drilled first few millimeters of each rivet; they could then be knocked out. We replaced the 6mm rivets with 8 (10?) mm bolts

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The fiber glass had delaminated slightly underneath one gudgeon

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Grease line nut split when reassembling

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Gudgeons are substantial; probably you could machine these 3-4 times before you need new ones. Original pins are 35 mm diameter

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To press the rudder into the gudgeons, we made a simple cradle

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As we used bolts instead of rivets, the bolt heads and nuts can be seen underneath the putty