[C320-list] Help with a smile you don't want

[Warren Updike]

At the leading and trailing edges of the keel where it joins the hull I have a thin crack that runs for about 6 inches.  I've not had hard groundings, well not too hard and not on rock, just mud.  It just seems like the putty is old.  

What is the stuff used to fair this joint?

Do I need to remove all of it or can I patch just these sections?

Warren & Pattie Updike
C320, #62, 1994, "Warr De Mar"
Frog Mortar Creek, Middle River
Chesapeake Bay