Keel Repair
You did not say if it was lead, cast iron, or encapsulated fiberglass. Also if it is a swing or fixed keel.Lead: Smooth out the broken area and get some two-part PC-7 epoxy.. the grey type. Mix the two equal parts together, but mix in some lead shot. Clean the area with isoprophyl alcohol. Fill in the area and smooth while still uncured. Sand, prime and paint.Iron: Again if is not to large you can use the PC-7, sans lead shot. Follow same procedure. Fiberglass: Same procedure, but check to see if the keel area is structurally sound. An opinion by your friendly yard service manager would help. Hope this helps.