An interesting post. I did almost the exact rebuild for my C&C 27 spade rudder.NACA profile and heavy reenforced internal SS flat stock across horizontally. I also extended the internal tabs to extend aft of the trailing edge to hang a self steering trim tab. 75 lbs lighter and probably 10x stronger.
Also rebalanced to reduce the helm
A couple of comparisons might be informative:
the difference in rudder performance I now question - the NACCA profile may not be as effective/ responsive and there is some literature that says that a simple plate actually works better - comments?
there may be an error in using stainless steel for internal reenforcements. SS anticorrosion properties depend on oxygen to form a protective barrier. My original rudder plate was heavily corroded with black hematite and I thought that it was actually carbon steel. I now realize that it wasn't . It may be better to use carbon steel and have it galvanized. I have quite a large milivoltage on my sacrificial zincs and can not retain a collar on my prop shaft for more than a month. The trim tab extensions where there were welds has corroded off. Comments?
I got this thread from looking for info on a newport 30. Can you tell me what the hull profile is? Spade and fin or full keel?