Well, Joe, you are the best judge, but I sometimes find starting with the
finer grades preferable because it takes a lot of effort to clean up after
something like 80, or even 100 on some woods.

That said, and without waiting for anyone else, I feel confident in saying
that the longest-lasting are resin-on-resin papers. Where wood is to be
moved and the least time wasted in changes, such as in surfacing, it's the
choice all through woodworking. The grit sticks through heat and cool, and
you can even clean (unload) it several times and have sand on the face.
CraftSupplies USA carries resin-on-resin (red) in both velcro and power lock
types. Only difficulty is that it's not available in open-coat varieties,
so the finer stuff can heat a surface if you don't take care. For me, care
means sanding with a flexible shaft, using my toolrest for support of the
handpiece, and barely touching the surface. Saves paper, checks, and
case-hardening, and is less likely, since I'm not pressing, to dish into
soft areas, face grain, or round the edges of bark-up stuff.

I feel confident in agreeing with the rest of the woodworking community that
stearated and open coat papers load and thereby heat, less than resin on
resin, and stearated, open coat paper least of all. Sanding with
lubricants is super-stearating. The trade-off is in the rate of removal
against load and final surface. I consider all the empirical data has been
weighed by the passage of time and sorted in the marketplace on the above.

Another tradeoff is between flexibility and grit retention. The adhesives
available are not as flexible as the backing to which they are attached, and
do not hold well if you're flexing a lot, which, once again, is something I
can control somewhat by not engaging in full-contact sanding, rather letting
the work come to my supported disk.

I guess I'm a lot less concerned about mesh tolerance than you. Most folks
I've found who have the scratch in smooth syndrome have done one of two
things - burnished (case-hardened) the surface with heat before sanding the
last grade's scratches out, or they didn't wipe between grits, and are still
kicking loose chunks of the last around with the current. If you sand one
grade beyond adequate, especially with the grain, you've got that one well
covered.

Take a peek at supported sanding at
http://personalpages.tds.net/~upgeorge/pin%20two.htm It's a beautiful
thing.

"Joe Fleming" wrote in message
...
Lyn,

Mike Mahoney has given this advice many time. Use sand paper like it is
free. I follow this advice and generally do not try to milk every last
bit
of sanding power out of a piece of sand paper or a sanding disk. Heat
checks are too nasty to risk on a few cents worth of paper.

With that as my criteria, I don't care so much about long life. I do care
about grit sizes, grit consistency and loading. Also, I don't have much
of
an ego on this - I generally start with 80 grit. To sand for minutes with
a
120 or 180 is silly when several seconds with 80 gets you off to a great,
quick start to your sanding routine.

Joe Fleming - San Diego
"Lyn J. Mangiameli" wrote in message
nk.net...
Ah, the sanding article, bane of my existance. I have two segments to
go. One on accessories for power sanding (pads, extensions, etc.) that I
just can't get very excited about, and the big study of the abrasive
types that has been driving me nuts. It is much harder to objectively
measure sand paper in a meaningful way that I expected.