I am considering a 1" steel keel shoe because it should be cheaper and tougher than lead, but also imagined an aluminum centerboard maybe 3/4" or so because it should be easier to shape the edges than steel and might provide more stability than wood. If I epoxy / fiberglass either or both items would galvanic action penetrate the plastic? fwiw, the project at hand is a Mackinaw which has a long straight keel which could come from a local (Chicago) steel yard, and if this seems workable I would prowl the scrap yards for the aluminum. Is this "smart but not wise?"