Rudder design

[Gerald]

In the only hurricane ever recorded in Brazil my 23' O'Day hit the beach. I had anchored it in front of the haul out area with two anchors that would hold under any conditions, or that is what I thought. I took off for a three day run up the coast in my yawl and upon return there was Catcher, resting on the beach. Four bottles of rum, a case of beer and it was floating again. It is now resting beside my shop waiting for a rebuild so that I can sell it. I could go into the story of its sinking a few months ago but I won't. I hate that boat!!!!!!!!!
When it hit the beach the rudder was lost. With a reward of a Kings ransom it has not turned up. I now have the opportunity to play with the design and learn something in the process. The full rudder is originally hung from the transom and the top of the rudder rakes forward. I would like to run a tube, with nylon bushings, down thru the inside of the hull perpendicular to the water line and manufacture a rudder. I see boats with the rudder raked forward at the top and others raked back at the top. What kind of trouble am I getting myself into?
Gerald

[mattb]

What kind of trouble? Probably a little bit of balance trouble since the rudder is part of the lateral surface area underwater. Moving the rudder forward may give the boat more weather helm, maybe not noticable.

You should also consider making sure the rudder is balanced. Where the rudder stock is relative to the surface of the rudder will determine how much effort is needed to move the rudder when the boat is moving through the water.

If you hate the boat so much why not just stick another similar rudder on the thing and get rid of it? The boat will be worth more without the modifications.

[Gerald]

"If you hate the boat so much why not just stick another similar rudder on the thing and get rid of it? The boat will be worth more without the modifications."
Good question. The O'Day factory closed here in the 1980s and it isn't likely I could find a used one. I know how to make one but I wouldn't learn anything. Within the next few months I need to go thru the same process on my 36' er. When I say learn, it also includes rounding up the parts. In many cases parts are not available and a visit to the machine shop is required.
As for modifications. I have already installed a small diesel in the center, a galley, etc. I have a swim platform from another boat that I would like to hang on the back since there is currently no way to easily enter the boat.
I read into what you have written that changing the angle of attach won't make a big difference so I will continue down the current path.
Thanks
Gerald