Soda blasting

[tom1394racing]

I use both soda and bead blasting on a regular basis in my home shop to clean parts. I have the Eastwood large blasting cabinet and a Harbor Frieght pressure blast unit with the soda blast conversion. I have plumbed the pressure blast unit into the blast cabinet by simply running the discharge hose through the hose opening in the cabinet. I can switch over from soda to bead and vice versa in about 10 minutes.

I use the glass bead for anything not delicate or where contamination is not an issue like heads, suspension parts and exhaust parts. Blast pressure with bead is a control factor. On really rusty or greasy parts, I run about 80 lbs and on more delicate stuff I back it down to around 40 lbs. I get probably 5-10 recycles on bead depending on how greasy the parts are.

I use soda on anything where contamination is a concern or where the surface texture or coating/plating needs to be preserved. Typical uses are cases, pistons, fan center hubs, fan straps, distributors and carb bodies. I usually run about 40-50 lbs pressure with soda. Recycling soda does not work well for me.

[304065]

My first job out of school was running a startup company that specialized in sodium bicarbonate blasting. Tough business, particularly because you were competing against sand and pressure washing and chemicals in a fairly capital intensive business with no regulatory barrier to entry. I'll save the rest for the MBA lecture . . . but what I learned was . . .

The reason the soda doesn't recycle is that it's fairly soft and shatters after impact. If you look at a soda crystal under a microscope, it has a number of very sharp facets that cut into the surface. Once that happens, it basically crumbles.

Now a little "rocks for jocks. . . " . Soda has a Mohs hardness of around 2.5-3.0. Aluminum oxide is a 9.0. Silica sand is around a 6 or 7. Glass beads are a 4.5-6.5. So how do you get good results with something that's soft? It's the sharp facets that do the work.

Church & Dwight, the manufacturer of Arm & Hammer baking soda, makes a number of different grades of soda-- from less aggressive to more, based on crystal structure and size. The stuff you want is called Armex Maintenance Formula XL (or "XL") for short-- biggest crystals, suitable for depainting.

I learned a lot in that business. . . enough to make me go to law school . . .

[Mr9146]

Not behind the Orange Curtain, but there's Anacapa Soda Blasting in Oxnard, CA.

http://anacapasodablasting.com/