I have a small blaster with rubber nozzles shaped to fit against various shapes, and a bag to catch the sand. It limits the amount of sand that goes everywhere. Got it from Grizzly Industrial. Probably wouldn't work well except for small areas, but a consideration for you.
I had my entire cab blasted by a guy who came to my place and set up a tent to enclose it. It was noisy though.
Interesting!! Did they primer it for you as well? Or did you do that afteward on your own?