For a non-directional matte finish, get a hook and loop backing pad for your random orbital sander and cut yourself some circles from maroon scotchbrite. They'll stick well enough to the hook and loop for use like this so long as you've got the sander in the random mode and not the spinning mode. Keep the surface wet, as this prevents bits of aluminum from clinging to the pad and scratching the surface. Pay attention to keeping the pad flat on the surface, and don't let it rock up on edge, and the resultant finish will be very uniform.
For a brushed finish, a pneumatic sander which resembles a dough rolling pin can be purchased. It has handles at each end and the drum rotates. Does an excellent job, but the sander itself is very expensive, on the order of $600+ US last time I noticed. |