Monday, February 21, 2011

Upper Rudder Supports (Rudder Shelves)

     Sea Ray uses a cast upper rudder support as a rudder shelf. The casting is bored to fit the top of the rudder stock, and provides additional bracing and support to the rudder port bearing. The factory packing gland and lock nut are located between the rudder port and rudder shelf. The previous post detailed the new rudder seals, and how they replace the packing glands. Fortunately, the new seals fit below the rudder shelf castings with room to spare. And, since I can keep the factory castings, I need to bring them up to my self imposed and extremely anal standards (on a boat, anal equates to "safe" and "reliable", so I take it as a compliment).
     Step one was a thorough cleaning, followed by sandblasting. Again, be sure to mask off any threaded holes or other areas of concern before blasting. In this case, the 1.5" bored hole for the rudder stock was carefully masked with tape. After blasting, both castings were placed in my hydraulic press, and straightened. For some reason, they were both bent - I can only assume they were used as steps or seats by previous owners/mechanics, or maybe something was dropped on them. Anyway, they are nice and straight now.
     Next, I placed the castings in my milling machine, found the center of the bearing bore, and threaded the castings to accept a standard grease fitting.
     I then carefully cut a small groove inside the bore, to accept and distribute the grease. Now I can grease this pivot point, and the grease will be distributed around the entire circumference of the rudder stock. As a finishing touch, I masked off the bearing bore a second time, and clear coated the casting with catalyst dried urethane. Just need to install them now...(Installation of these requires that they be precisely located over the rudder stock, and then also shimmed such that they are at a precise 90 degrees to the rudder stock. These steps will be detailed in a later post.)

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