Many boats (read: nearly all) with bolted on lead keels will have to deal with this problem eventually - it's not limited to Catalina's. First let me describe what's happening. The keel bolts to a keel boss, which is a short extension of the hull (usually 8" - 10")molded in during the building of the hull. The intension is to transfer or spread the stress loads into the hull, but as many of us know it doesn't work like it should and the result is a crack that often starts at the front of the keel/keel boss joint and extends back. On my '81 Pearson Flyer it also cracks along the back edge. In my case it doesn't cause any leaking, but it may with certain models. The cause is due to the relative flexibility of the hull compared to the stiff keel. There are important points to consider in deciding how to repair the crack. Does the crack cause leaking? How much work or money are you prepared to spend? do you want to make a repair that will be (hopefully) permanent? To repair it permanently requires adding sufficient fiberglass to make the transfer of stress loading into the hull as intended. This involves grinding the gelcoat off the hull a couple feet out from the keel boss and down the keel a couple feet past the keel/keel boss joint. We recommend using a biaxial glass of at least 15 oz. (like our Episize® 737 or 738). Consider the 0° direction to be a line running straight down the centerline and the beam extending down the keel. The glass is applied so that it maintains the +/- 45° fiber orientation relative to the 0° direction. The first layer of glass spans the entire ground out area - from 2 ft. beyond the flair to 2 ft. below the joint. A second layer is then applied that is about 8" shorter on both ends, then a third that is similarly about 8" shorter than the second. Once this is cured, it gets sanded, faired, and barrier coated. This stepped method of laminations should provide adequate stiffness and distribute the load over a larger area without inducing stress point at the end of the lamination. I expect this is what the $1500 estimate involves. If it's not leaking into the bilge, as in my situation, it isn't really necessary to make the repair outlined above. What I have done is simply grind out a trough along the joint about 5" wide centered over the joint, laminate some 4" biaxial tape in the trough then apply the fairing etc. sand it and call it good. I have seen the crack reappear but still get no leaking, so I have just ground the small cracks out a bit and filled it with epoxy filled with a high density filler (our 406 silica or 403 microfibers). The main point here is to understand the issues involved in a full structural repair so you can make an informed decision how you want to proceed.
Catalina Smile Repair
- Thread starter Rick D
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