David, IMO, the leading edge is subject to impact from "stuff" in the water. In my area after a big rain event, I see all sorts of things in the lake. Just think it's a good practice to prepare for hitting something.
Similarly, I think a trailing edge should be repaired with high strength material. Not sure about others, but Touche's keel's trailing edge is shaped to a fine 1/4 inch square edge. I wanted high strength there due to the thin shape. Using a lightweight fairing compound on the keel sides should fine. Touche' has Awlfair to smooth and shape the sides and underbody. If the keel has been sand to bright lead, many recommend a primer prior to painting. The lead will begin to oxidize immediately so speed is apparently important. The neatest technique for coating bright lead I've ever heard about is to apply epoxy with a scrubbing pad. The pad removes the oxidation and applies the epoxy all at once. I want to say that came from Wally but not sure. Dennis C. On Sun, Nov 22, 2015 at 10:03 AM, David Knecht via CnC-List < cnc-list@cnc-list.com> wrote: > Hi Dennis- Why would you need such a high strength material on the leading > edge of a keel? This seems like a pretty low stress area. I tend to think > I should worry more about adhesion strength and the different materials > have a large range of surface preparation procedures for adhesion to the > lead. I have talked to a few people about keel repair and no one has had > problems with the repair failing and the materials have ranged from > thickened epoxy with chopped glass to marine tex putty to lightweight epoxy > putties (Interlux/pettit). > Here is what I have found so far on properties > > Marine Tex: > tensile strength 4000 psi > compression strength 13000 psi > > West system epoxy resin > tensile strength 7000 psi > compression strength 11000 psi > > One other question- is the lead keel normally coated with something before > bottom paint? I am having the bottom stripped this winter and not sure if > a primer is needed on the keel before bottom paint. > Dave > > On Nov 21, 2015, at 11:03 AM, Dennis C. via CnC-List < > cnc-list@cnc-list.com> wrote: > >
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