[Shop-talk] Question on Dryway sanding / cleanup

[Wayne]

Hey Guys....

I'm prep'ing a room to paint for the first time since it was built.  The 
drywall in this room and several others is "nappy" -- there seem to be 
fibers from the cardboard facing or somewhere else that were raked up 
and stick through the primer and paint.

The wife and I have been attacking this for two days with an electric 
sander to knock down the fuzzies, and clean up some of the mud joints. 
This is going slowly and making a HELLUVA mess.

Questions;
* Any ideas what would cause nappy drywall?  Moisture exposure perhaps?

* Any better methods for sanding?  Since we're starting with a painted 
surface, I don't think the "screen" type abrasive cloths I've seen sold 
for drywall work would work well.

* Any suggestions on cleanup?  The vac' is still leaving all kinds of 
crap behind.  I'm thinking maybe tack-cloths like the body-work guys use?

   -Thanks for any input!
       Wayne