Guys, it really depends on WHAT "scuff pad" we are talking about. Scuff pads DO have a "grit" just as paper does. It can be used JUST as sandpaper so "scuff" something for paint,primer or clear. It can't be used to "level" a surface as you do with sand paper, but to "scuff" it for simple adhesion, you bet your bippy they can be used.

The "Red" #37447 (they call Maroon) 3M for instance is great for scuffing primer prior to more primer being applied or for chassis parts and things like that. Anywhere that you will be applying primer or something with a little "fill". It is rated at something like 320 grit as I remember.

Gray scuff pads like 3M # 34448 is much finer and about 600-800. It is used everyday in the autobody industry to prepare panels for paint and clear. "Scuffing" a panels OEM clear for a blend for instance, it is used every single day across America, it is the "standard of the industry" for this use.

White scuff pads (don't remember the 3M number) 2404 is the Martin Senour number available at NAPA auto parts stores. It has no grit, and must be used with a "scuffing gel" that HAS abrasive (not all do). It is used on things like plastic bumpers so they don't get scratched.

Scuff pads are the only way to fly when doing things like under hoods and door jambs and stuff like that. But again, it is not for "surfacing", but merely for "scuffing" for adhesion.

Brian