Paint your keel
Yes you can paint your keel while on the trailer. If it is partly hidden, you must first lift the boat about 5 inches above the bunks. This yu can do with a hydraulic jack, placed once at midpoint near tansom (with good padding), then blocked on the bunk. This will let the bottom of the keel swing down to expose most of it. If you wnat to do more, then go forward and lift forward of the keel again midpoint latterally, and block. This will let get to the 4 bolts that let you drop the keel out of the tunnel. Only do this with suitable lateral support to the keel, and use a floor jack carefully. Also, be careful that you don't twist off the bolts. They say use only 30 lbs. torque when you put new ones with washers back in which you would surely want to do if you get this far. With the keel now below the boat, it is a good time to check for wear on the pin and keel hole. Look in Catalina Direct for replacement parts if you need. At same time check cable at bottom of keel. You can then paint up in the tunnel with bottom paint too. This is strongly recommended especially if you are in salt water. I recommend one of those little sponge strip mop heads about 4 inches in diameter as a paint brush, attached to a dowell. Strangely, I just completed this job including retrofit hanger on my 1975 Cat 22 so I know it can be done. But it takes some time, perhaps a week of a few hours every day. My main problem was the boat moved a little sideways when I initially raised it which ultimately made realligning the bolts difficult. Next time, I'll be sure its all straight at that point. Also, I had to drive about 150 mi. round trip to get a machine shop to mill the new carrier to the right slot size. And yes, if you use your boat in salt water you surely should get bottom paint over all surfaces. All kinds of marine organisms might otherwise find a nice home. You should also put on new zinc's on the keel close to the pin assembly. to lessen corrosion problems. If you can find the technical manual put out by the Catalina Associationn, they provide most of the "how-to's". Good Luck, Dick