Official Luthiers Forum!

A also use a 5" ROS for top and back, and a small "mouse" sander for the sides. Cutaways get the hand treatment. It pays to have an assortment of blocks, different in hardness and shape. 1" and 1 1/2" cut dowels faced with cork are great for tight curves. PSA sandpaper rules.
To avoid the corduroy effect on spruce I find it better to sand cross grain until, and including, the very last grit (220 for me, and if I sand by hand, which occasionally happens). Then do a few passes along the grain. A hard block helps.
I have a run of the mill DeWalt 5" ROS and I connect my VAC to the back, it is the cleanest you can get and I have no use for a downdraft table. The combo is heavy and perhaps cumbersome, but I have two hands, and how long does it take to finish sand a guitar?
In terms of technique, 2 simple things works for me: change the paper often and sand lightly (do not dig in) in order to avoid deep scratches. Let the paper do the work. Last passes are always along the grain.
I dry sand the finish with 400 grit until the penultimate coat, I then switch to wet 600, then wet 1000 before the last coat. I wet sand 1000 and 1200 before buffing with Menzerna olive, then ivory bars. If I missed something wet sanding, I dry sand the area with 2000, and go back to the buffer.
Buy the best (and correct) paper you can get, it pays in the end.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Laurent, I think I'll try your sanding schedule.
If you didn't have a buffer,
what would you use to buff by hand?
Also, where would rottenstone fit in there,
if at all?
I'm not looking to get a super high polished finish.
Thanks!

One of my first wood working jobs was in a fancy furniture refinishing shop in Wayne Pennsylvania, where all I was permitted to do was sand. I got into into it and learned to really bring out the details of any particular wood, until it was perfectly clear. There is definitely a Zen to it IMO, and I credit it to my appreciation of the beauty of wood, something I never had to that extent before.

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"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.

I wouldn't. I buffed a lot of guitars with a couple of 12" wheels in the drill press. It works, you just have to be a little more careful. You have a drill press, don't you?
There is absolutely no way you can get equivalent results by hand.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I have and use the Dewalt 5' ROS. I also have an old Craftsman 1/4 sheet regular sander with a ROS capability. Question: what is the difference between ROS and a regular sander? I know it's dumb..

The only think I can think of is the regular sander is less aggressive. Is there an advantage/disadvantage from using one over the other? Should one use the regular sander for some situations and the ROS for others?

Steve

From Wikipedia:

"Random orbit sanders, also called Dual-Action or D.A. sanders (referring to the rotation of the disk and the head) are hand-held power sanders where the action is a random orbit. They were first introduced in the early 1990s and quickly became tremendously popular. Random orbit sanders combine almost the speed and aggressiveness of a belt sander, with the ability to produce a finer finish than that available from a standard, slow speed, orbital finishing sander.

"The random orbit is produced by simultaneously spinning the sanding disk and moving it in an ellipse, which ensures that no single part of the abrasive material travels the same path twice. Because of this unique random sanding action, the tool does not leave swirl marks, and it is not sensitive to the direction of the wood grain." [For the rest of this brief article, go to http://en.wikipedia.org/wiki/Random_orbit_sander]

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Tim Allen
"Never hurry, never rest."