Hi Roberta - questions, questions questions...
Can the copper just be roughed up with sandpaper instead? Probably
How exactly is that done? What type of equipment is a sand blaster
exactly? How do they fit in a studio setting? It must be very messy.
It's done with a sandblaster - very easy, when you have one. Our
sandblaster is a plastic box about 18" square with rubber gloves -
like a clean room thing. We got it at Otto Frei, though I altered
the nozzle and valve for better flow, but you can see it there. The
other essential ingredient is a genuine air compressor, which is
often the hard part. A little putt-putt air brush kind of thing will
either not work or not very well. Ours needs 100 psi and a fair
amount of CFM. That means a real compressor, mostly. We have a few
uses for ours, so we need it anyway. Once you get it and plug it in,
it's incredibly simple to use.