Maybe I'm missing something. When you say "grind on the rudder", what part of the rudder are you talking about?
Right now the rudders are fully raked, which means that the rudder is touching the casting. In order to get more rake I'd have to grind the rudder in that area.
Actually, because the rudders have been fully raked for a while, they've already started the process just by wearing against the casting in that area.
