This blog documents the modifications necessary to get seaworthy (warts and all), then the adventures (hopefully) on board our Trailer Sailer 6.1 metre Jarcat6 Catamaran, Kismet.

Saturday, 25 November 2017

Rudder Changes

Here is a look at the rudder arrangement on our Jarcat. This picture is from the sellers advertisement.

It's not obvious from the picture, but the port (left) rudder is 25mm away from the bottom of the hull when the rudder is fully down. The starboard (right) rudder clears by a massive 50mm. The advise is that this should be about 2mm. As it is now, the rudder boxes will drag in the water and the rudders will collect seaweed and garbage.

The rudder pintles (the pivot pins) are mounted on the transom (the back vertical bit of the boat). The gudgeons - the bits with the hole that drops over the pintle, are mounted on the rudders - more correctly the rudder boxes  (these are the things that the kick-up rudders fold into and are pivoted from).

My plan is to move the gudgeons down on the rudder boxes. The cross-arm connecting the port and starboard rudder boxes and the tiller arrangement will then have to be re-worked. The tiller will end up below the cross-arm - in the picture it's above the cross-arm.

This picture show why the tiller is a "chuck away". It hits you in the kneecap and in no way clears the outboard motor.

Here are the rudder boxes removed from the boat, the gudgeons removed, and the gudgeon mounting holes filled.

To fill the holes, I used 1/4" hardwood dowel cut about 10-12mm shorter than the length of the hole. I squashed one end so it would stay put in the hole equidistantly from each end then I blocked the lower end of the hole with masking tape and filled the hole with slightly thickened epoxy - it took a while for it to dribble down.

In the same picture (click on the picture for a better look) you can see the rudder gudgeons. Another small surprise - two different brands - Ronstan and Riley. The Ronstan (the ones with the flange filled in) were on the starboard rudder box and the Riley on the port. Ronstan (RF905 - no longer available nor is the RF2505) have a 52mm gap (the rudder boxes are 52-53mm) and Riley (RM591) have a 51mm gap (they measure 50mm). There will have to be some sanding and repainting to fit them. I will also place Ronstan on the top and Riley on the bottom - just for symmetry. At least something will be symmetrical- more on that later...

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