Keel Zincs
Roger: I'll tell you how I did it. Mabye it will give you some ideas. I drilled straight through the keel and used 1/4-20 threaded rod. Originally I used brass threaded rod, now I use stainless steel, either one will work. I then put nuts onto each end of the threaded rod. I should also mention that I modify the zincs by increasing the diameter of the counterbore that they come with. Usually the ones that I buy have a 5/16 nut pressed into one half, and a socket head cap screw (Allen head screw) in the other half. I don't use these. I use 1/4-20 stainless steel nuts which sit in the counter bores. The threaded rod is cut flush or below the top surface of the zincs. I assume that you will be mounting these with the boat on the trailer. You must put them AFT of the pin that supports the keel, and I recommend that you put them at least 1/2 inch down from the bottom of the hull. Remember that when the keel is lowered, you don't want them to be rotated into the slot in front of the keel pin. That's why they must be aft of the pin. I have had some variation in the diameter that I could purchase, and that I why I recommend that you put them so that there is at least 1/2 inch clearance from the hull. I counterbore them on a little lathe that I have, but you may be able to do this with a spade bit if you do apply your zincs the way I do. I then fill in the counterbores around the nuts with silicone sealer to make everything smooth. Remember you have to remove the bottom paint from under the zincs to have them work, and don't let the silicone sealer coat the surface of the zincs either. I actually have 2 sets on my keel. The second set is an inch or two aft of the first set. I replace one of the 2 sets every year, so I have a new and an old set on every spring. They do corrode away. This is good, because it shows that they are working. The water where I keep my boat is slightly salty. I hope this helps give you some ideas. It's been a long time since I drilled through my keel, and if I remember correctly, the metal was very hard. (It might be tough to tap threads into the keel, but others may have a comment on that. Just don't break a drill bit or a tap. The other precaution I want to give you, if you do it the way I did, is that you should try hard to get the bit aligned so that it is straight through, otherwise one side will be higher than the other and the zinc could be too close to the keel slot. Aldo
