Rudder replacement

[Andrew Harvey]

When we purchased the boat in 2001 it had a fin keel. For any of you familiar with Georgian Bay, a fin keel is not the best scenario.
Fortunately another member of located in Michigan was looking for a fin to replace his shoal keel. Our respective boat yards chopped off keels. I trucked it down to Detroit with a borrowed truck and trailer. It was really interesting crossing customs but that is another story. Along with my new keel came an elliptical rudder which I never installed. From what I have read, this rudder in conjunction with shoal keel will sail better and reduce prop walk. Does anyone have any comments or tips on the rudder replacement project ?

[Ron Hill]

Andrew : There is a specific elliptical rudder for a fin keel and another different elliptical rudder for a wing keel!! 
Look in the late 1990's Mainsheet Tech notes and you'll find the diagrams that I published.

Look in WiKI because there have been numerous posts on the "how to problems" you might encounter in replacing a rudder. 

The elliptical rudder make a world of difference especially on "heading up"; not too sure about the other claims. 
I modified my rudder into an elliptical design about 10 years ago and it solves the heading up, but with more surface area behind the pivot point it does make for a slightly "heavier" rudder. 
In the MkII boats that was compensated for with a larger diameter wheel (more mechanical advantage!!).

A few thoughts

[Clay Greene]

Andrew,

We replaced the original rudder in our 1989 C34 (wing keel) with the elliptical rudder.  A couple of thoughts:

1.  You may need to drill new holes in the rudder post.  I would not expect that the existing holes (if there are any) will match up with your quadrant in relationship to the rudder cap, although you may get lucky. 

2.  I don't know how new the elliptical rudder is but at a certain point Catalina went to a twin-walled rudder post.  We needed to go to a specialized machine shop in order to get the rudder holes drilled and the rudder post cut down to the appropriate height.  Even so, it was reported to be quite the project for them and they were off by about a quarter inch, which necessitated us running out to get the rudder cap ground down.

3.  Taking off the steering cables and removing the quadrant is easy enough but you need someone small who is mechanically handy in order to do it.  It is a very small space in the aft lazarette.  Fortunately, I have a wife who is both of those things. 

4.  The larger, elliptical rudder definitely helped with the weather helm issue and the boat generally steered better.  It was probably a little heavier of a feel but not anything that I felt justified a larger wheel.  Ron, of course, is absolutely right that the Mark II boats came with a larger wheel and that is a logical reason. 

Good luck!

[Steve_in_lex]

Any comments on this non-standard design, offered by Catalina Direct?

http://www.catalinadirect.com/index.cfm/product/2557_343/rudder-for-c-34-c-36brhdpe-unifoil.cfm

[Ron Hill]

Steve : I haven't gone into any exacting measurements, but I don' believe that there is enough rudder surface area on their proposed replacement rudder!!
 
The whole idea of an new elliptical rudder was to increase the rudder surface area so the C34 wouldn't unintentionally head-up into the wind when the breeze go to 18kts.
That was the problem with the original rudder - Not enough rudder when the boat nose in and heeled.

Any rudder replacement - I'd stick with Catalina factory NOT Direct!!

A thought

[Ron Hill]

Guys : My comments are primarily for the WING Keeled C34 boats.
 
The comments that I've received from the fin keel owners, say they have not experienced that dramatic a performance change -- when changing to the new elliptical rudder.