On Wednesday night, I stopped at the hardware store and bought epoxy, silicone caulking, and the tools I needed to do my fin repair.
On Thursday morning, I stopped and picked up my boat and threw it on my car roof. At lunch on Thursday, the weather was nice, it was warm enough to use the epoxy and silicone, so I put my boat on slings in the parking lot and set to work.
Job one was to extract the fin without doing any more damage to the boat. So, I sliced the existing caulking on both sides, and front and back and then slowly worked the fin out of the fin box. Then it was on to caulking removal. I was able to get all the caulking off the fin and most of the caulk off of the outer surface of the hull. I was able to cut the caulking away from the top of the fin box where the seam was between it and the hull of the boat. I cleaned this up with the knife as much as I could and I could see where the seam was delaminated on both side from about half way back to the stern.
I mixed up some epoxy and delicately smushed it into the crack all the way around trying to avoid getting any drips down the sides of box. Then I waited about 10 minutes for the epoxy to setup and stop being tacky. The last thing I wanted was to permanently glue the fin in with epoxy. That would be bad. While I waited, I put down masking tape on the hull marking the outside line of where I wanted caulk. I did the same thing on the fin.
Once it was dry to the touch, I carefully reset the fin in the box. It appeared that the box stayed laminated all the way around during this process and the fin appeared to my eye to be aligned and in the same position as before. At that point, I put down a big bead of caulking along both sides, trying to make sure that all voids were completely filled. I then took a caulk bead tool and used it to form a small 45 degree fillet between the hull and the fin along both sides. I carefully faired the caulking at the front and back to make sure that it was completely filled and smooth. Then I pulled away the tape. It actually looked pretty good for an amateur job.
I left the boat as it was for the afternoon, and when I left for the night, the fin was stable in the slot. I suspect that it is not entirely perfect, but this morning when I used the boat, it tracked straight and didn’t leak, so I think it’s good for the rest of the season. I might get a pro to look at it this winter.