Justin,
Recently tore my whole boat apart to glue the tramp frame together (too much flex!!) I decided that while the boat is apart and in pieces, I would get all of the cast aluminum parts re-anodized. This operation results in a hard, durable and off the shelf looking part. All of the parts were done for about $50 Canadian.
The parts included the corner castings, the mast step, rudder and tiller castings.
Just an other alternative to painting
Tim