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Ted Mooney, P.E. RET
Pine Beach, NJ
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Vibratory finishing leaves smut on stainless steel
Q. I recently purchased a Rosler E420 Vibe Bowl and Z800 Centrifuge. The equipment was purchased to debur some long thin flat 302 stainless parts. The deburring process is working well, but we are getting a gray smutty surface film on the parts that does not come off during passivation. Any ideas on how to eliminate the smut?
Kurt DubeEngineer - Southington, Connecticut
November 13, 2018
A. Kurt,
I'd reach out to your chemical vendor. I've seen smut on brass vibratory processes before and we pumped a low concentration specialty cleaner recommended by our vendor through and it cleaned them all right up. I had tried some homebrew acid mixes and other burnishes first and nothing was nearly as effective.
- Agawam, Massachusetts
November 15, 2018
A. Are your parts flat? If they nest during the processing, then you may want to look into dry organic abrasive process media
AF Kenton
retired business owner - Hatboro, Pennsylvania
December 8, 2018
Q. The parts are flat and narrow. .030 thick x .128 wide x 5-1/2 long. I've been working with a local chemist to come up with a solution to remove the smut. Conventional alkaline cleaners and nitric have not done a very good job in removing the smut. So far we found ultrasonic cleaning with a special formulated cleaner design to help remove the smut to be the best solution.
Kurt S. Dube [returning]Medical Components - Southington, Connecticut, USA
December 10, 2018
A. I am a big fan of ultrasonic cleaning systems; however, I you want to try a mechanical system, try a mass finishing system using dry organic media with pumice.
AF Kenton
retired business owner - Hatboro, Pennsylvania
December 12, 2018
Q. Thanks AF,
This week I tried running parts in corn cob media to remove the oil from the stamping operation, and it worked very well.
I then ran the parts in corn cob media after vibratory deburr to remove the surface smut, and this too worked very well. The two extra operations add some additional time and cost, but this option is still better than sending the parts outside.
Do you think adding pumice to the corn cob would be beneficial? If so, what ratio should I use?
Medical Components - Southington, Connecticut, USA
December 13, 2018
A. If you are having good results with dry media, stay with it. If you are taking too long, by adding 120 grit pumice you will speed up the cleaning cycle, but may still need the finish without pumice.
AF Kenton
retired business owner - Hatboro, Pennsylvania
December 18, 2018
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