Which blast media for plastics?

[Bennylava]

This guy seems to cover it pretty well, but he didn't mention plastics specifically. From this guide it seems to me like it would be walnut shell, but I'm not sure if walnut shell comes in different grits like corn. To clarify I'm talking about using it in a blast cabinet. I've got a lot of various plastics that I'm going to paint, and I want to prep the surface for adhesion promoter quickly. It would take forever and a day to sand all this stuff by hand. Thanks!

 

[Hammer1963]

Walnut shells will work on the more rigid plastics, however you should be aware of the heat from friction that can occur. You need to identify the plastic type and go from there. Sanding is not as bad as you may think provided you have the correct grits and use the proper procedure. I use a combination of methods including all of the above