Where the
world gathers for metal finishing
Q&As since 1989


-----

Removing dings after passivation

2004

The company I work for makes parts for the aerospace industry.

Sometimes we are required to sends those parts to be passivated and occasionally they come back with dings and scratches.I would like to know if removing the dings and scratches would compromise the integrity of the passivation.

thank you for your help,

ODILE ROYEA
aerospace mfg quality control - HOLDERNESS, NEW HAMPSHIRE, USA

---

Yes, removing those dings will compromise the integrity of the passivation. The mere presence of dings and scratches is a good indication that the passivity has been compromised (how do you know they occurred before passivation rather than from banging into steel after passivation?).

To me the question is not how to remove the dings, but why do you accept the dings?

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004

---

As Ted says, you cannot mechanically do anything to the surface after the passivation step without destroying the passive layer. The passivation, rinse and drying must be the last thing you do before packaging and shipping the parts.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2004