i really mean spanwise, when i worked at schempp-hirth 6 years ago they always sanded spanwise for finish sanding. and i have been doing it that way at a nationally known glider refinishing company for 12 years.

On Thursday, March 24, 2016 at 5:30:06 PM UTC-4, Michael Opitz wrote:
i take sections of wing and draw a line with pencil from leading edge
to
tr=
ailing edge every 18 inches or so. then, with 800 (you can use 600)
you'll
=
sand two sections at a time using spanwise strokes, working from
leading
ed=
ge to trailing edge.

Did you really mean spanwise and not chordwise??? When I worked at
S-H, we NEVER sanded spanwise. It was either chordwise or
alternating 45 degrees off chordwise. FWIW......