Heat is the issue. A board beaten into burnished condition by dull blades
or sanded unto ridiculous grits under power can turn back oil finishes. One
of the benefits of setting with water before final sanding - by hand - is
that it helps break this "case-hardening." Most glues are water-based to
some degree, so the benefits should extend to an edge produced by a
moderately dull jointer.


my jointer leaves a shine but it is very sharp just ask my hands (G) but I have
done sanding to 1200 grit with a palm sander and my oil and wax finish works
just as it does if I sand to 320.00

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.