DIY Soda Blasting

I have sent several batches of parts to a soda blasting service, and been very happy with the results (see here). However, for a couple of reasons I decided that it would be nice to have the capability at home.

There is a fair amount of information on the web, but I never could find a clear guide that fit my needs and circumstances.  Here I will document what worked well for me.



Prior to this endeavor, I owned zero compressor equipment and tools.  A compressor with enough CFM to power a soda blasting setup is fairly expensive.  Fortunately, my father and brother-in-law both own  Harbor Freight Compressor Model #62380 (here) and let me borrow them (thanks!).

Key Compressor Specs

• 2.5 CFM @ 90 PSI, 3.4 CFM @ 40 PSI
• 6-Gallon
• 150 PSI max, 120 PSI trigger
• 1.5 HP
• $130, frequently $100 with coupon

By connecting two of these in parallel, the CFM, storage capacity and HP are all doubled, so you get a 5 CFM @ 90 PSI compressor.  There are other guides available on how to connect two compressors in parallel, but I will mention that these compressors are rated at 9.8 Amps and there's a good chance your electrical circuits are rated for 15 Amps max (check your circuit breaker rating to determine).  I recommend running the compressors from outlets on different electrical circuits.  

Since soda blasting requires a near continuous supply of air at 70-90 PSI, CFM @ 90 PSI is the key spec.  Soda blast guns should tell you how many CFM @ 90 PSI they consume, although numbers are hard to find and of questionable accuracy when available.  For instance, I ended up buying the Craftsman Portable Media Blast Kit 16707 from Summit Racing (great customer service!).  The Sears website gives the average CFM as 1.8, while the product manual gives the air consumption as 9.5 SCFM, and neither one specifies @ PSI.  At least this gun comes with 3 different air-jet sizes, which should change the CFM required.  In the end, I just used the mid-sized jet that came installed and could blast nearly continuously at ~80 PSI with the two compressors in parallel    

My Setup

The Craftsman blast gun is a siphon-feed type and I had been concerned about how well it would feed, but it worked well.  The only problem I had was on a relatively humid day when the desiccant in the compressor's drier was used-up and the tip started clogging.  Fitting a new drier solved the problem.  I did keep the soda on a cart so gravity could help a bit.

For soda, I purchased a 50 lb. bag of the Armex XL (coarse) Soda from Harbor Freight. The medium grade probably would have worked too.  I reclaimed the soda and filtered it with a kitchen strainer I had on hand.  If I had been worked on a painted or highly polished surface, I would have been more careful about filtering reclaimed soda.

Aluminum Oil Tube, Before

Aluminum Oil Tube, After

Here are a few notes on how soda blasting affected different materials and surfaces.

Rubber Hoses:  worked great

Hard Plastic:  worked great, but left a slightly rough surface

Aluminum, polished:  cleaned well, but left a matte finish

Aluminum, rough:  cleaned well, no noticeable change in surface

Stainless steel, polished:  cleaned well and preserved polished finish

Steel, yellow-zinc plated:  cleaned well and preserved plating