As you might recall, we lost a rudder while at sea crossing from Minerva Reef to Tonga – it was an utter rudder disaster.  We managed ok for over 1,000nm with just one rudder before we were able to get our hands on a temproary rudder which we then had custom fit to our boat.

But it is time to replace both rudders now that we are in New Zealand and the boat is hauled out.  We researched many different options including having Jefa Rudders custom design them from the UK; a boat builder in Auckland, NZ;  Foss Boatbuilders in Los Angeles; and considered having Norsand Boatyard do the work. There were pros and cons with each company, so we decided to hire local professionals that we had first hand knowledge of their expertise and skills.  They had already worked on our boat and had years of glassing experience.

The Rudder Shaft

The first thing we have to do is design and build the rudder shafts (or posts).  Technically, both of our rudder shafts are “in tact” but the tines or fingers on the port shaft are damaged.  At the top of the shaft you will see a ring and one tine sticking out.  This is the front of tine and there is supposed to be a back.  The middle tine is broken half way in the front and has no back portion and the bottom tine is completely gone.

Damaged Rudder Shaft with broken tines

We engaged our friend Rob at RH Precision while we were still in Tonga.  We love Rob!  He has done several stainless projects for us and is just a gem to work with!  He has all of the fun tools and machines for welding stainless and aluminum.  Matt finds the dimensions and all of the measurements to our existing rudder shafts (thanx to the Catana Mailing Group and several other Catana owners who shared their specifications).  

We triple check all of the measurements with our existing rudder shafts (both the damaged one and the one that is still in tact).  And then we double check them again.  Matt specifically orders 6082 aluminum (from High Grade Metals in NZ) which is stronger than our original lighter aluminum.  Rob works his magic and expertly replicates our rudder shafts as per the diagram.

Bigger is Better

Rob then drills the holes. There are 4 holes near the top which is how we connect the post to the boat and 4 holes for the tines.  We decided to go with 16mm tines which are bigger and stronger than our current 14mm tines.

I assumed Rob would be able to do the tines as well, but I was wrong.  We had to get the rods for the tines…hmmm.  Rob sends us to Vulcan Ullrich Aluminium in Whangarei where we are able to purchase a 5m of 16mm rod.  We have them cut it into (8) 280mm pieces and we take the almost 4m of extra rod back to Rob as a gift.

The Final Steps

Rob pounds the 8 pieces into each hole for us and then we take it to Absolute Stainless to tack them in place so they wont move (tack weld).  Yep, this is a process.  It doesn’t take long to tack weld them as we were able to pick them up the next morning.  The next step is to have the rudder shafts anodized.  So, we drive them to Auckland (2.5hrs each way) to Alert Anodising where they will put 25 micron hard black to protect them.  We had wanted marine grade but evidently there was a mix up. Rob assured us it would be fine and that this was still very good.

10 days later we make the drive back to Auckland to pick up our newly anodized rudder posts.  

The shafts look so sexy!  I am not sure why I think they look sexy with the anodizing, but I do!  We laid the new shaft next to the old shaft and what a difference.  The new shafts are about 27cm longer and weigh almost 1 kilo more than the older shafts.  Compare the damaged shaft to the new one on the right photo.

Now we are ready for the blades.  Stay tuned for part II of the Rudder Rebuild.

Our blog posts run 10-12 weeks behind actual live events.  This blog post occured during November 2023.