Abnormal to have cracks in the keel stub joint, IMHO. Usually an indication of the joint being compromised. Until our boat struck a rock, the joint was crack free. Dropped the keel, cleaned and re-bed the stub joint with 3M-5200. After putting everything back together, no leaks, no cracks after thousands of cruising miles. That was in 2004.
Hi Terry - did you notice any signs of water intrusion when you dropped the keel?
I agree with
@Tally Ho, cracks are very common in keel-hull joints, but I'm not sure if they're not signs of trouble further down the line due to water intrusion in the joint. I see boats everywhere, on the hard, with joints that weep after rain. To me, that's a sign that the keel-hull joint is starting to come loose. How deep water is intruding into the joint is the big question, and I'm not sure if it's readily obvious how much water is getting into the joint without serious excavation.
Keel-hull joints are one of the most mystifying parts of sailboat maintenance for me and other sailors. There isn't a lot of information out there on how to maintain them. I suspect the first and most important part of maintaining the joint is to make sure that keel bolts are torqued, but how much torque to put on them isn't obvious. Since the keel-hull connection is loaded in opposite sides on each tack, I think it's important to maintain enough tension on the bolts to keep deflections in the joint on the windward side of the connection to a minimum.
The mfg's stay kind of silent on the issue (with some exceptions - I've seen specific recommendations from J-Boats and Hunter, but the torque values recommended for similar diameter bolts are very different). Most sailors I know never torque their keel bolts, and I think that's because there just isn't a lot of good information out there about the issue. There's a lot of concern about breaking the bolts or crushing the laminate, from what I've seen.