: A mistake I made sanding was that I sanded with 60 grit on a small pad before
: I went to a fairing board. After sanding through several grit with the
: long fairing board I put a precoat of epoxy on the boat. I noticed the
: epoxy darkened in a few areas and after checking I noticed that these dark
: areas still had some of the 60 grit sanding lines in them and soaked up
: more epoxy than the finer grit lines thus making these area’s darker. I
: will check my sanding much closer the next time.

In general I try to go from large to small and stiff to soft as well as course to fine. A stiff, large fairing board will bridge over low spots to knock of the high spots. However, a stiff backer will cause the sander to make deep scratches. A soft backer will conform to the surface and won't make as deep scratches.