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


-----

Is this advisable to use agitation in hard chromium while bath is running?

We are using hard chromium plating in out process shop. Our deposition range is 5-8 microns. Still we have improper deposition. I expect one of the reasons for improper deposition is improper agitation. We use to agitate the bath once per 10 lots. Is it enough for distributed chemistry and temperature in bath? And Is this advisable to use agitation while bath is running?

Thanks in advance...

V. Ranga Bhuvana Balaji
Process Shop - India
2005

---

Continuous air agitation is not a problem usually and can be an excellent idea unless you use a partially soluble fluoride catalyst designed to settle to the bottom of the tank.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

Slow mechanical agitation, if it is feasible, can also help even deposition of chrome on your components.

K.V.Phadnis
Balmer Lawrie-Van Leer Ltd. - Mumbai, India
2005

---

Thanks a lot for your response...

Actually before we were using continuous agitation. But at that time we got some defects like pitted deposition and peel off. So we stopped continuous agitation. Is it possible that continuous agitation can cause above mentioned defects?

V. Ranga Bhuvana Balaji
Process Shop - India
2005

---

You didn't answer my implied question about whether you use a sparingly soluble fluoride catalyst or not. If there are solids in the bath, keeping them in suspension will cause that kind of problem. If the bath does not require solids, it is possible to filter them out. In other words, my guess, until you tell us about the bath, is that suspended solids rather than air per se is causing the problem.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005