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  for Metal Finishing 1989-2024
  

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Dust on stainless steel surface after wet blasting

In our shop we use to sand blasting the welded stainless steel components and other surfaces to achieve a unified color. The blasting is a wet process, i.e. water is mixed with glass bead. Subsequently the stainless steel surface is flush with high pressure water jet. No matter how thorough we do the flushing, there is always a layer of dust left behind on the metal surface. Can anyone be kind enough to suggest a reason and a solution how to remove the dust without manually wiping off.

Thank you.

Alfred B S Lee
- Hongkong, China
2000

I WOULD FIRST TRY A SPRAY OF 20% FLUORIDE. IF THAT WERE NOT SUCCESSFUL, I WOULD USE A NITRIC/Fluoride BLEND. THE Fluoride WOULD ELIMINATE ANY GLASS RESIDUAL AND NOT AFFECT THE STAINLESS TOO MUCH. THE NITRIC/HF MIXTURE MAY REQUIRE ADDITIONAL STEPS.

RICH PODOLSKI
CHEMICAL PROCESSING & ACCESSORIES - LINCOLNSHIRE, IL -USA
2000

Alfred: How are you passivating the stainless after your blasting process? The dust is "broken glass" that becomes a finely divided powder that is like trying to rinse talcum powder off a rough surface. A passivation step after blasting should help this condition and HAS to be done to properly condition the stainless.

Dan Weaver
- Toccoa, Georgia
2000