Milton that is good advice !!! My C22 had some delamination around the keel locking bolt, there is a piece of steel that wraps around the aft end of the keel trunk that has a nut welded on to it than they drilled through the strap and tapped the strap so the threads go all the way through the nut and the strap. Than they laid up several layers of of fiberglass over top of the strap to totally incase it. The fiber glass on mine separated right where the strap is. I cut out the bad fiberglass, bent the strap out away from the port side of of the keel trunk and used a four and a half inch angle grinder with a course sanding dish to remove any rust from the strap and to rough up its surface for a better bond. Next I cleaned up the rust residue from the strap and keel trunk and using a new sanding disk I removed any additional bad fiberglass and roughed up that whole area. Next I bonded the strap back to the keel trunk by whetting out the surfaces to be bonded with West System Epoxy, than using a V notched spreader I put more epoxy that was thickened with West System microfibers. than used some wood blocking and a hydraulic bottle jack to hold the strap tightly in place for 48 hours. Next I cut out several different sized rectangles of fiberglass cloth an cut a round hole (slightly smaller than the the nut in each piece. I than sanded the entire area again for a better bond and laid up the fiber glass, one piece at a time, start by laying the first piece in place and using a 6 inch and 2 inch paint rollers with West System roller covers, roll the epoxy on top of the the cloth while smoothing the cloth as you go, than roll over it with some pressure to push cloth tight and squeeze out any voids and air bubbles. At this point the cloth should be transparent, re-roll or use a chip brush with additional epoxy resin on any area of the cloth that is not transparent. Repeat until all layers have been laid up. Most of the area that I laid up is about a Quarter inch thick and tapers out around the edges and I built it up so it was flush with the face of the nut than i whetted out the entire hole including the nut than added some epoxy thickened with microfibers to fill in the threads and build out the walls. Next I put 2 layers of fiberglass cloth over the nut, once it cured I re-tapped the threads, using the proper sized tap for the nut (I think it is a half inch course thread) and an appropriate sized wood twist drill bit for the tap, I was only drilling fiberglass and resin. Run the drill bit through the top 2 layers of fiberglass than through the hole and run the tap all the way through the hole so it is threaded all the way. Use a small wooden coffee stir or Q-Tip and put a moderate amount of marine grease on the threads in the hole and also on the Keel Locking Bolt an screw the bolt back in, DONE!!!!! No more leak.