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From: Tom MacNaughton
Date: 14 Jan 2008
Time: 14:58:48 -0500
Remote Name: 66.252.35.229
You don’t want to cast bolts into the lead. If you do they can’t be removed if they ever corrode enough to require replacement. Now normally a silicon bronze rod made into a bolt will last a very long time. Of course occasionally someone does something stupid like wires the keel bolts to a “bonding” system, or “lightning protection” system and manages to create a situation where they get eaten. I’ve even seen keel bolts with a battery charger carefully attached to them thus guaranteeing they’d be eaten up in the shortest possible time. Normally the right bolts should last longer than any one person would ever own the boat. However I have seen boats that have been owned by the first owner as long as 60 years. In that case one change of keel bolts might be needed I suppose. My feeling is that there is always the possibility of damage and the need to repair the boat and you might as well make it easy for your descendents or subsequent owners who may have to replace those bolts someday. Normally I would set up cores in the mold for each bolt with a larger diameter core on the bottom end where the bottom of the keel was so that you ended up with a hole for the bolt and a nice recess to put a nut into inset into the bottom of the keel. This way you have a nut on the bottom and a nut on the top which gives you plenty of options for getting things apart. A slightly nicer way to do it is to arrange the mold so that rectangular pockets are cast into the sides and a hole goes up from there through the top of the casting. This allows you to have the nuts in a pocket that is not right on the bottom of the keel. That makes it easier to work on the keel bolts and less likely that the bolts themselves will be damaged in grounding. Just for completeness I should mention that you can also drill or cast circular holes through the side of the keel into which a large diameter piece of round shafting can be set to form a nut for the keel bolts. These round pocket nuts require the most care in drilling but when trimmed flush with the side of the keel look very nice. The disadvantage is that you can’t loosen these nuts from the outside, which other pocket nut types are sometimes arranged to be able to do. This means that all work on removing the bolt is done on the inside, but it most often is anyway. So far as I know this type of pocket nut, which is also excellent for holding together deadwood parts was unique to our shop. I’ve never seen anyone else do it. We’ve done some repairs that some people said were impossible with this type of fastening which has a wonderful ability to draw parts together without problems. There’s a lot more that can be said about keel bolts. They are only scary in contemplation. Once you work out a step by step procedure and given that you don’t try to “ace” anything, you’ll do just fine. I will say that with keel bolts the only people I’ve ever seen get in real trouble were people who were trying to figure out a “simpler” way rather than just use conventional methods.