what i did was take a piece of airfame- 6" length for body tubes 2" and up- and cut about a third out of the length of it. glue a hand block on the back then put some of the 3m sticky back sandpaper inside. sands body tubes pretty good.
Yeah. That's how I usually do it -- I picked up a lifetime supply of 2" wide industrial sanding belts on ebay -- but you have to secure the airframe in order to use both hands. Now if I only had a lathe...