Auto body repair & detailing: body work - fillers, cheese grater, plastic body filler

Question
I am repairing/restoring an old truck.  I have the body off the chassis and have sand blasted everything.  I'm now ready to repair minor dents.  I have purchased USC body filler because I was told it is a very good filler.  My question is how do I stop my sandpaper from loading up with the initial "tacky" or "gummy" surface of the body filler?  It wastes sandpaper and my time trying to sand with paper that is loaded up fast. Once I get by the surface everything sands fine.  I am using Norton 80 grit as a starting point for my initial sanding.  I am using an Ingersol Rand air board for most of my beginning sanding work.
Doug

Answer
Hi Doug,

Many auto body technicians start with what is called a "cheese grater file" in the industry. This removes the top layer of material and actually it will allow you to work the area sooner than you actually could with sand paper. Here is a link to give you an idea of what I'm referring to: http://www.repaintsupply.com/pd-surform-cheese-grater-blade.cfm