by Thom Fitzpatrick
How rusty is the part you intend to blast?
For really heavy rust on frame pieces I use #30-#60 copper slag. It will mar the metal, but the pieces I was using it on were being cut out anyway.
For nicer work, I use #80 garnet. I used this to do some wheels, and it came out beautifully.
If you're just removing paint, use medium to fine walnut shells. I used these on a Datsun roadster, and it works great! I can take paint off one single layer at a time with this stuff!