I work in the surface preparation business, manufacturing portable shot blast and grinding equipment, mainly dealing with concrete surfaces, and steel surfaces such as aircraft carrier decks and storage tanks. Though I do not have first hand experience with soda blast, we have had customers who have used that process with good results. One downside of water/soda blast is the slury thats left over when you're finished. Depending on how much soda you inject into the water jet, this could range from a light haze on the ground to a soupy mess. Clean up can take as long as the job itself. In many locations, the contaminates that were removed and are now mixed in with the slurry are an environmental concern as they are washed away in the water stream.
Don't get me wrong , it's a very efective process in the right situations. Soda blast is used largely for the removal of hazardous coatings and contaminates, the residue of which is disposed of using hazardous materials guidlines. But it also is used in auto body prep because it leaves behind a clean light profile.
One thing I would be concerned with what you're talking about would be putting water on your freshly blasted white metal finish. It doesn't take long for rust to start setting up.
Glass bead blast works well also but can stick into the metal and produce fisheyes in the finish if you don't catch them during prep. I have a hand held blaster called a Speed Blaster that works very well on small or narrow items such as frames, axles, wheels, trim etc. I run glass beads or sand in it with good results. You could do large body parts with it but it will take longer that a larger unit.
Personally, I would stick with the sand blast as it can be contained easier, plus you can recycle you blast media. Or you can just blast away in your back yard and just rake the sand in when your done..... Hard to do with soda.
Rezman
