Re: Secret to building
Doesn't look too bad.
If it were me, I'd first check and repair any deeper cracks or holes.
Then I'd carefully grind away the gelcoat on the keel area and about an inch up on either side.
Then lay progressively smaller strips of glass in resin until you're near the thickness you want, starting with the first strip being as wide as the ground area.
When that hardens, sand it to profile then smooth the shape out with marine-tex or gelcoat, then final sand. If you don't gelcoat I'd recommend some paint.
An alternative quick/redneck repair would be to put enough filler (marine-tex if you have the cash, or resin mixed with cabosil and milled fibers) in a fat line down the center of a piece of flexible plastic or plastic coated paper to make up the height, then wrap it around the keel like a mold. Wait until it hardens then peel off the paper and sand.. it should form a nice rounded corner. Easy to mess that up, though.
Erik
