: 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.

Once runs, sags etc. dry, will take longer than the rest of the finish, they can be sanded flush. You should be sanding between coats with 220 max., with 400 you're not getting a good mechanical bond between coats. Sand before the final coat with 320 enough to dull the surface, no more.

Bill H.