"Leo Lichtman" wrote in message
...

"George" wrote: Ah, the power of the placebo!
^^^^^^^^^^^^^^^
I asked my son's shop teacher about this, and he said, "Just reverse the
sandpaper."

However, I think I can explain why reversing the rotation works: As
sanding progresses in a singoe direction, short hairs of wood fibre are
pressed down and not removed. When the rotation is reversed, these fibres
meet the sandpaper head-on, and are at least partially removed.

Of course you are not dealing with flat stock where the grain climbs or
dives pretty much on the whole board, but a bowl. Means there will be a
pair of points while rotating in either direction where you pick up,
pressing down at the opposite. Solution to one problem creates another.
That you reverse and do more sanding may remove more wood, certainly makes
you feel involved (placebo), and if power sanding results in a crossing
pattern in reverse if you use the opposite clock position on the disk.

As to visibility, not sure. I can see the other side of the bowl better if
my hand isn't in the way, especially given the hams I have at the end of my
arms. Since things are rotating, I see everything I need to see, just a bit
later. Would simplify dust pickup placement, but that which carried and
ejected from the rim would be more likely to affect your nose, coming at you
as it would be.