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


-----

Iron content in chromic acid anodizing

2007

Can anyone help me with following?

1. What is the role of iron in chromic acid anodizing process?
2. What is the generic control limit for iron?
3. HOW TO ESTIMATE IRON IN ANODIZING SOLUTION?
4. How to reduce or remove the iron from anodizing solution?

We are doing chromic acid anodizing of aluminium rivets and have been asked to check the iron content by our customer, but are not getting any technical help in analysing the same.

Thanks in advance.

Biren Desai
Plating shop employee - Bangalore, India

---

Dear Biren Desai

The content of iron in Chromic acid anodising should be as in Sulfuric Acid Anodising (50 ppm). It could be measured by mass spectroscopy and it is very difficult to remove from the tank due to the chrome reduction, so the easiest way is to dump the bath.

Best regards,

Anne Deacon Juhl
- - Trustrup Denmark
2007

Thanks a lot for the help.

Biren Desai
- Bangalore, India
January 7, 2008

---

can any one help me teach what exactly is the purpose of anodizing/de anodizing of rivets. dhinesh rao - Bangalore, India January 23, 2009 Hi, Dhinesh. Anodizing provides a corrosion resistant, hard, decorative finish on rivets, letting them match the aluminum they are attaching. Regards, Ted Mooney, P.E. Striving to live Aloha finishing.com - Pine Beach, New Jersey January 27, 2009