In response to a lot of off-list questions about varathane and it's application here's another url that tells some more about the qualities of flecto: http://www.polyclay.com/flecto.htm
Me personally I sand the comb flat on a polished marble surface starting with 120 and going to 320 or 400, (not completely grinding out all the marks, just creating a relatively smooth surface). The first coat I brush on VERY lightly, because you can get a lot of warpage etc. if you load up or dip the comb. Then I sand very lightly on the flat surface between coats till I'm satisfied with a smooth sealed, flat surface to meet the reedplates (usually 5-7 coats) being careful not to build up too much in the slots, edges, front teeth etc (yeah, I always gargle and brush afterwards...). then I wait a few days before attaching plates after final sanding (and redrilling of the holes).
