Skim Coat or Sand?

The walls in my home have a number of coats of paint, and have lost their smoothness. Which would be better, skim coat with joint compound, or just sand them with an orbital disk sander? The latter seems like less work, although messier. I am concerned about the longterm adhesion of the skim coat to the existing flat paint.
Appreciate any comments.
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Both. But first get a good painter's lamp, so you can easily see the irregularities on the wall surface. Using a medium-grit (120-180) disc, use a ROS to remove any old bumps and lightly roughen depressions you'll be applying joint compound to. I'm assuming you don't have grease/oil on paint, else you want to use TSP too. (I'm also assuming your ROS has built-in dust-collection, else you really want that.)
I'd apply compound as little as possible to smooth surface, using lamp as above to see what you're doing. Too little on a given pass is much preferable to too much. (Don't insist on one pass.)
John
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Thanks. Should I then use a PVA primer, or something like Guardz?
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On Fri, 21 Jan 2005 16:39:41 -0500, "Buck Turgidson"

Gardz is THE answer. It will penetrate & bond any unsound layers underneath. Suprised you'd heard of it.
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Forget the power sander. Painters use these large sanding tools on sticks to smooth out walls in a few minutes, Vacuum, touch it up with patching compound, recheck and sand then paint. If the current paint isn't peeling you should be ok.

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I have used a pole sander with 80 grit sandpaper to take out all the nubs and irregularities on old overpainted plaster walls. Use drywall mud to fill divots and depressions.

their
just
skim
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