The authoritative public forum
  for Metal Finishing since 1989
-----

Effect of blast media (glass bead/baking soda) on Chromium oxide layer of stainless steel

We are currently evaluating baking soda and glass bead blasting to assist in the cleaning of stainless steel (T304, T304L, T316L grades)chemical storage tanks prior to reconditioning. Small residuals of dried spilled chemicals, paper pulp or other dried debris were tanks were used, labels, label adhesive, rust and stencil paint are among the many items that can be effectively cleaned by this process. Can the glass bead &/or baking soda effect the chromium oxide layer(COL) and make the stainless steel less resistant to corrosion? Media selection, size and technique can vary the surface finish from "as is" smooth to an aggressive "rough" appearance; would that likewise have bearing on the (COL)? If so, is passivating or other processes advised to restore the expected corrosion resistance?

Thank you,

Don Umbriaco
- Chicago, Illinois, USA
2003

---

Use the soda blasting alone. There is a media that does not change the surface profile. If you "open" the surface, it will be harder to clean the next time, and will cause your contaminants to adhere even worse than before. After soda blasting, rinse with good quality water (no iron) and it will repassivate to a degree.

Dan Weaver
- Toccoa, Georgia
2003