Horstman 45 rudder mod

When I bought my Tri-Star45 I noticed the main hull depth was 36" while the spade rudder is 42" . Now I find the rudder shaft has crevice corrosion just as we are ending a stay in the yard, so I am looking at options.
1. Replace w/ similar -- it's a heavy beast, 2" shaft and 4 or 5" of plywood w/ FRP sheath, I would like to go hollow shaft and foam/skin, but no carbon fiber tube seems strong enough, primarily in torque/twist.
2. Move it to the transom. This presentsproblems of how to get vertical from a counter stern, relocation of steering cables/quadrant, and changes in performance and steering. I would now have to consider a) a welded framework similar to windvane, b) cassette with retracting rudder or c) direct to transom with/without skeg to protect and suspend lower end.

The Tri-Star 45 is a big, heavy (18ton USCG) boat so the rudder must be well-reinforced. Horstman just died (wasn't very communicative before) and a designer I contacted wanted a set of prints and 2 hrs retainer, an ante of ~ $1500.

 

The rudder lasted quite a long time. Build it the same, but use a corrosion resistant alloy like Aquamet 22 and it should last for decades. Also, make sure there is no stray current grounding through the rudder. That will create electrolytic corrosion which looks similar to crevice corrosion.

 

Sad to hear of Eds passing . The spade rudder and kick up rudder are the same profile as the dagger boards . So your options would be going back with the spade rudder , converting the kick up rudder for the 31 to a 45 , or a dagger board rudder .

 

I just stumbled on this thread. Ed is very much alive I spoke with him this morning. I am building a 27-9. The plans I have include a kick up rudder. You could probably get a similar design from him for your boat.