I can't say enough about how much useful information I have found in this news group. As I don't like freeloaders, I think I can contribute something here.
As my nickname suggests, I do a LOT of sanding...and I mean a LOT. And because I learn so much in this NG about my first love, woodworking, I am more that happy to share what I have learned about sanding since the days when solid surface countertops only came in 4 colours. (now 400)
Envision this: a 4-ft x 6-ft kitchen island top.
Black or very dark colour.
Windows everywhere.
At the point of purchase, the customer signs a waiver.."This is black, ma'm...it will show everything. Do NOT call me if the electrician drags his tool-belt all over it."
But, as it is over 30" wide, I need to make a seam during fabrication. And I get to sand it till the seam disappears. Then I get to make it shiny..semi gloss. And optically flat. Only the guys at Mt. Palomar Observatory have a more daunting task when they polish their mirrors... ok..I embellish..
The most important things to remember,
1) Buy the best you can afford. One can drop a $1000 on a sander/sucker combo. Fein comes to mind. My current favourite is Festool's Rotex 150 with a CT-22 sucker. Not only does the Rotex suck dirt off the work, it also blows air in the middle of the pad. See animation under Products>animation>RO 150EI also use a LOT of sanding sponges..fine on one side, medium on the other. Handy little things, those... CAREFUL when you sand along the edge of an oak board along the grain. Large splinters can travel up through the sponge and accordion into your right hand's index finger's second joint, requiring surgery and enough antibiotics to make a grown man puke. Or so I'm told.
Hope this helps. Rob
PS.. I am not affiliated with Festool, Mirka, Pfizer, Heineken, Chivas, Bentley Motor Cars, or Meg Ryan. And the rumour that my Aunt Bee is a lesbian, is just that.... a rumour, okay??