Yeah, that was me. Iused a soda blaster on my 73 Bronco.
It was OK, but I found it to be very slow, and VERY messy. If you don't use water, then the dust is incredible. If you use water, then the mess is incredible. I ended up using stripper on the main flat parts, aluminum oxide on the cracks and smaller parts, and wet sanded the rest. I washed the entire body with TSP in my power washer.
I then used a ScotchBrite pad on a rotary sander and scuffed the entire surface.
The soda blasted surface has a dark haze that does prevent flash rust, but, as borne out in the link you posted, this doesn't seem to be a very good painting surface.
My observation, after weeks of prep work, is that Al Oxide at 100 PSI does a fine job, and doesn't seem to have any negative effects. I wouldn't blast any large flat or modestly contoured panels for fear of warping, but those are easy to strip with wet sanding or stripper, followed by the scotchbrite pad.
I like the singature of one of the posts....
Good paint jobs aren't cheap; cheap paint jobns aren't good...
Pretty much says it all. I have probably 200 hours invested in stripping and prepping this car. If I had paid someone to do this, it would have cost $10K+
