Centerboard Tube

Centerboard Tube Overhaul

While the centerboard was out of the boat, I decided to check the condition of the cable tube and the blocks top and bottom. The deck block is housed in a sleeve in the under-deck part of the fitting; the on-deck plate serves as a protector for the cable and block. This is what I found when I opened the deck fitting:

The fitting was both sealed and shimmed using the original silicone-based sealant. (What is this stuff?). The under-deck part of the fitting did not fit flush with the underside of the deck but was about 1/4” low on the stb side. This was why the bolts turned so easily! The pulley was jammed against one side of the sleeve and was damaged beyond repair. After cleaning everything I put it back together, re-aligned it, and cast an epoxy shim on the underside of the deck using the under-deck plate as a mold/base. Now I can actually tighten the bolts when I do the final assembly. Then I found that the newly-aligned fitting caused the pulley to jam on the top plate, so I had the machine shop make me a new, correctly aligned on-deck plate along with the new top and bottom pulleys they were making out of the same plastic they use for rudder bearings, with a stainless steel bushing in the center.

Now for the fitting at the top of the trunk. I discovered that this pulley is pinned inside a shoe that fits into the top of the trunk, and the shoe was sealed using a rubber gasket and plenty of the silicone stuff. It bolts into a plate which is, in turn, screwed and sealed into the fiberglass.  

Top of Trunk Shoe Plate w/bolts out

Trunk Shoe

Trunk Plate

 I made a new gasket out of 3/16” neoprene.  There is a “keeper” pin in the fitting to prevent the cable from moving too far aft and jamming. This was the old one.  It was worn almost all the way through by the stainless steel cable:

Before I put everything back together I carefully checked the condition of the tube itself. That, at least, was OK. Now everything is back together, the blocks actually turn, and the new 3/16” dyneema pennant is threaded and runs freely, awaiting the re-furbished centerboard.