In preparation for this season, I notice rust along the keel and hull connection, Hunter 30 1991 bolt on keel. I also notice small rust spots all over the keel. I have begun cleaning out the keel Hull connection, first question is do I try to get rid of all the oxidation on the iron? In some spots it's 1/4 to 3/8" thick. The small little spots not associated with the connection, is this from failed sealer coat? Do I need to blast the whole keel down to raw metal? and if I do what do I put back on before bottom paint? the keel bolts in the bilge look ok no rust. The rust spots are slightly blistered.