Hi-

Check out George Dyson's book Baidarka. He uses stop signs for rudders and paddle blades.
6061-T6 aluminum. Great way to recycle!

Jack

: The stainless is probably fine, just difficult to cut. I made a retracting
: skeg for a plastic boat and found the best thing to use for the blade is a
: street sign. The aluminum material used for street signs is tough stuff,
: ever seen one broken? These signs flex in the wind for years. Years ago, I
: found these signss were the only things that would last for number plates
: on racng motorcycles I went to my local highway dept. and asked for an old
: used sign. They gave me a several. The best thickness is about 3/32"

: I used a jigsaw to cut the material and finished it with a stationary belt
: sander. I tapered the leading edge a little.

: Cant help you with design, I just made up my own for the stern skeg I made.

: Larry C.