For my frame I used part silica and part fine play sand. The silica I got was too coarse so it plugged up the blaster. Make sure your sand is very dry or it will plug up the blaster. Make sure the air is dry or it will plug up the blaster. If you make sure the sand will easily fit through the nozzle and it is dry you will be ok.
I have been using stripper for the body panels.

Don't you know who I think I am?
I've been thinkin' about freaking out. If I could just find the time.
http://community.webshots.com/user/ifrizlfri