Blasting media - glass bead, soda etc.

I'm not adverse to buying more/different shot for the job.

I need to clean up engine cases, so I don't want to do anything radical, but I want a nice finish when I'm done on the exterior. So, is a multi-stage shot an option? I understand it's not like sanding, where you start with a corse grit and move to a finer grit.

I haven't used the glass yet - I'm also wondering about recommended PSI/CFM. You can tell I've never done this before.

Sandblasting is all about the CFM, the PSI only increase the speed and impact of the media.

Cafe_to_go you may have an issue with CFM, nozzle are normally match with the airjet to increase the suction of the media.
Changing out the nozzle is not always the cure if you don't have the volume of air. What is the screen size of the walnut you are using?

To get the hose in sand type of media up to work better, it a quick fix of inserting a pipe in the end of the hose then into the media and drilling a small hole in the pipe just above the media to allow a air and media mix. Much kike a carb mixing the fuel and air, it prevents purdging. (too much media and not enough air).

Tintin feels free to call me next week at work and I'll fix you up.

FD