My centerboard seems to stick from time to time. I have removed it cleaned and polished it. Still it sticks - but only sometimes. Does anyone recommend lubrication or will that collect dirt and make matters worse? If lubricatoin helps, what should it be?
If it isn't the gasket, the centerboard's pivot has a grease that feels just like the axle grease from my tailer. I imagine that it is something a little different though, because it has to be waterproof.
Another thing to check is the centerboard slot. On some older boats, it sometimes happens (rarely) that the sides of the slot become deformed and the board rubs against it. This is easy to check, just run the board slowly up and down while watching it from above. If so, you might be able to sand the board enough to make it slip by. Keep in mind older boards have a foam core, so don't overdo the sanding!
Another place where the board could bind is the upper "lip" of the slot. If so, the lip is easy to grind down with a coarse sanding disk.
The lip on the slot can be cut all the way back to the case walls. On Coronado 15s with gybing strips on the centerboard, sections of the lip need to be cut off to allow the strips clearance. Cutting the lip off won't solve rubbing issues however, as they are happening further down in the case.
The metal pin and sleeve on the fiberglass inside the board does not need grease at all. In my experience, boards don't like to come up or go down becuase:
1. stuff on the board rubbing against the gasket
2. A a stiff gasket(my C15 has a really nice sailcloth one that seals the well beautifully, but makes the board not want to move as areault of the "grip" the gasket has on the board. The factory rubber ones, unless they have become hard, shouldn't give you trouble.
You don't use gybing strips, do you?
How much effort are you putting in when it becomes difficult to get the board up? Often, a good nudge on the head of the board will coax it all the way up. Unless you have bottom paint on the board, there should be pletny of clearance to get the board up. You might be having the cb hangars rubbing against the board. You can space them away from the board with some nylon washers.