Just finished my artic tern 17'(novice builder); so far 3 coats of varnish. I'm going to finish with five coats then going kayaking. My questions are: 1)when I get a small run can I just sand the run then varnish that area... and how do I blend the varnish to that area? 2) before my last coat how much sanding to I do? Do I take the varnish down to a dull finish or just pass the sand paper lightly over the boat? I'm sanding between each coat using 400 grit wet.