Rudder cleaning / treatment?

Any recommendations on cleaning and old rudder blade?  I painted the head and the blade really looks bad!  Sand it?  Chemical treatment?  Should I put anything on it after it clean?

Use a white sandable primer spray paint made by Rustoleum. It dries soft for easy wet sending and is durable enough so that you do not need any other finish. The tip is from the Neff's. FS 3512