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Green plating is not ok

November 17, 2010

Dear Sir,
I have to face a problem with green plating as rainbow colour, colour is not ok. some spot in head and what should be current passage in acid tank for that plating to become good?
And also clear me we use brightener either 1044M-1044R or 21M-21R for brightness of plated material. if in case brightener is more in tank than that, what problem may occur?
and what should be add in acid tank for that brightener to become less?
pl note that I have recently join finishing department.
With Regards
Hp Singh

Hamender Pratap
plating shop employee - Rohtak, Haryana & India

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bit of a problem, You mention proprietary chemicals that I am not familiar with and do not say what kind of plating you are doing.
Rainbow coloring is commonly caused by not enough plating in that area. That means you need longer plating time or racks with thieves and or shields to reduce the plate on the edges and send more of plate to the center of the part.

Note that you do not mention bath temp, anode to cathode spacing, amps per sq inch, concentration of the bath, level of trash ions and unwanted organics.

That makes it hard for most people to give you a good answer. We are not mind readers.

Have you contacted your tech services department of your chemical vendor. They are by far the most knowledgeable people for your plating line.

James Watts
- Navarre, Florida
November 18, 2010

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Dear Sir,
process may be acid zinc ,problem may be due to
1) excess brightener
2) low zinc metal
3) low thickness due to low dip time in plating.

rahul potphode
- Pune, Maharashtra, India
December 26, 2010

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January 2, 2011

Dear Mr. HP,

I agree with Rahul Potphode,

1- Excess Brightener in Acid Zinc Bath.
2- Low metal contents in Acid Zinc Bath.
3- Less plating time.

Most probably you are doing barrel plating, in screw heads you will find iridescent/ rainbow shades.

After passivation and final rinsing and drying we may notice rainbow shades where components are touch each other.

Regards,

Parashar S R

Sanjeev Raman Parashar
- PUNE, Maharashtra, India