Greetings all. This winter I intend to build a new rudder for my 1968 Venture 21. It currently has a fixed rudder and I would like to make it retractable. One design I'm considering would use a piece of 1/2 inch thick aluminum 6061-T6 for the lower section (basically the part below the water line) instead of wood. I already have plans to build the top section out of 6061, it will match up to the 6061 tiller I built last winter. My experience is in metal working, so I have the resources to do a professional quality job in cutting, fastening, fitting, etc.
I only question this in wondering if the lack of a foil shape on the rudder will really be that noticeable (I know, the fanatical purists are cringing at this point
). Do you think it will flutter in the water at 5.5-6 knots (hull speed)?
I think strength will be ample, does anyone disagree?
My original rudder is teak and wrapped in fiberglass and is in very good shape. I intend to save it and don't care to use it for a donor. My only source for teak is on-line, wow! Its very expensive!
Please notice what I'm sailing, I'm not made of money. I can do the aluminum set-up for about $150 total. I only sail on fresh water, so I'm not too worried about corrosion.
Thanks for your thoughts. Flat.