First of all do not overburden yourselves with the thoughts that your keel may fall. Such an occurrence would have dire consequences but is usually an uncommon one. Not all bolts are likely to be in the same condition and not all are likely to fail at once, save a real humdinger of a grounding. To be able to get an early warning of a possible problem you may re-torque the bolts and nuts periodically. A broken, weak or unseated bolt should be revealed at this time. If one or more should fail the torqueing process it may be time to have the keel dropped and all bolts replaced. A unseated bolt can be pulled out and if it is found in fairly good condition it can be replaced and reseated without having to drop the keel. In older boats trying to remove bolts that seem to be holding strong is taking a chance in causing a premature failure.
