Category Archives: Hull

Sacrificial anode

The anode on the propeller shaft wears out in two seasons. We also had a problem with corrosion of the heat exchanger (a new one was provided by Vetus under warranty) and corrosion of the ball valve on the sea water intake for the engine.

To hopefully avoid premature death of our new engine and other fittings, we have fitted a small pen anode in the sea water circuit of the engine as well as a 5 kg anode on the hull, wired into the engine. Let’s see what happens…

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As close to the propeller and sea water intake as possible, with a free line of sight to both.

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Bronze thru hull post connects the zinc anode to the 16 mm2 tinned copper wire from the engine

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

 

Storm damage repairs finished

As planned, the repairs of Anna were finished by the end of March and today she was taken down to the harbour from the winter storage warehouse. I’ve ordered a new sprayhood (dodger) and stainless steel tubes (the original are made of aluminium) – supposed to be finished before the end of April.

The repair works were made by Öresunds Marin in Höganäs, Sweden. Nice job and finished on time. Our insurance company, Länsförsäkringar, has handled the claim in the best possible way – we are very satisfied with them.

 

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Fitting wind vane

Building the Bouvaan wind vane (www.hollandwindvane.com) from the kit took about 80-100 hours. If one has access to a mechanical workshop, that is  a huge advantage, although building it in your garage is quite possible. We have fitted it without removing the swim ladder, awaiting further evaluation…

The wind vane fits just below the mizzen boom when the axle is about 150mm below the toe rail – that also is as far up as it can be mounted while still having the uppermost bolts accessible thru the lockers in the aft cabin.

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Antifouling etc

We stripped the hull of loose antifouling, put on new antifouling, put on new stickers with name and registration number, cleaned and waterproofed the sprayhood and cockpit tent and put her back in the water.

Bow prop installation

The previous owner of our boat is running a business (www.joinme.se) in Southern Sweden focusing on indoor winter storage of pleasure boats as well as technically advanced maintenance jobs, such as installation of new engines, electronics etc. Just before we bought his Hallberg-Rassy 41, he had fitted a brand new bow prop (or is it called a bow thruster?), a 8hp Vetus BOW95, including some immense cables running from the battery bank.

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Measuring all the time, with a laser…

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… and cutting once.