When I tried to put the boat's dagger board into its trunk prior to my first sail, it would barely enter the trunk at all and got completely stuck after only a few inches of insertion. I tried to sand it a bit, got almost nowhere with a random orbital sander and 60 grit paper, and instead tried lubricating the board with soap. That worked well enough for our initial launch, but it was clear there was a bigger issue that needed to be addressed.

I consulted an online forum and received advice to both sand down the board to make it fit, and to try to fix whatever was wrong with the trunk, which appeared to be no longer in the original shape, perhaps due to some wood swelling over the years. The structure around the trunk seemed sound and secure, however, and rather than take apart something I was unsure if I could get back together properly, I decided to sand down the board.

A friend from my sailing club loaned me a small belt sander and I used 50 grit paper to take off the old varnish (which was still in pretty good shape), and then used the belt sander and an orbital sander with 80 grit paper to take the wood down and fair the board. After quite a bit of time, I got it so slide smoothly into and out of the trunk, and it performed well during a subsequent sail.

I debated whether to epoxy the board and then varnish, apply epoxy alone, or some other approach. My belt sander friend offered that varnish alone should be sufficient, and I'm going to go with that for now. Next step is to continue sanding with finer sandpaper, up to probably 180 grit, and then apply varnish, hopefully just enough to protect the board and not make it too thick to go back in the trunk.