-- The Home Page of the Finishing Industry
23+ years of serious education, promoting Aloha,
& the most fun you can have in metal finishing smiley
    no popups, no spam
on this site
current topics
topic 11292

Staining in brass plating


We are plating brass on plastic parts, but in this moment brass is staining after one day.

The cycle is:
after bright nickel electroplating:
brass plating-one minute
Electrolac (I think is a electrolytic chromate)
Electrodip (immersion chromate)
This process has been used for many time and the problem appear one month ago. Let me to know your recommendations and if some product similar to Electrolac.

Carlos Godoy
PEMSA - MÈxico, D.F.


Most brass plating is cyanide based, and I assume yours is. Cyanide plating solutions are very prone to 'bleed out', and they require excellent rinsing to prevent it. Is it possible that the problem is really back in the rinses after plating, rather than further into the process?

Ted Mooney, Teds signature
Ted Mooney, P.E.
Pine Beach, New Jersey


Mr Mooney is right about the rinsing. You need three DM water rinses pH aroud 6.0 to 6.5 after Nickel and again after brass. After brass you need a 2 % H2 SO4 rinse before the lacquers/ anti-tarnish.

Khozem Vahaanwala
Khozem Vahaanwala
Saify Ind supporting advertiser
Bangalore, Karnataka, India

saify logo

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.