[Jeff_H]

With all due respect nothing you are suggesting makes sense to me. There just about is no such thing as a ''solid glass rudder''. Most are foam rudders with glass skins and a stainless steel or composite rudder post and internal structure. If weight is not important, it is pretty easy to build a plywood outboard rudder and if you sheath it in a laminate of epoxy and fiberglass it will last for an extremely long time.

Painted wood will not be as strong or as durable as either of the above and solid glass would be obscenely heavy with no real gain in strength.
Jeff