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"Tarnishing of copper plated parts"



2005

Hello
I have a doubt about tarnishing of copper plated parts. Plated from cyanide bath(Metallic cu-35 gms/lit, Free cyanide-25 gms/lit (KCN)),chromic acid dipped,polished with soap water,final dip in de-ionised water and anti tarnish dip found brownish colour change on keeping (with in 2-3 days). What to do, please.....

jose george
Jose K G
- Cochin, Kerala, India
^


2005

Mr.Jose

Use of anti tarnish is better.When you use antitarnish no need of chromic acid. try to introduce temperature to antitarnish and good rinses in between plating and antitarnish will solve your problem.

p gurumoorthi
P. Gurumoorthi




electroplating process chemicals
Chennai, Tamilnadu, India

^


2005

Hi Jose,

Use 20 gpl of Sodium Dichromate for a minutes rinse in slightly warm water, it will work for your purpose.

Khozem Vahaanwala
Khozem Vahaanwala
Saify Ind
supporting advertiser
Bengaluru, Karnataka, India
saify logo
^


2005

Hi,

Please go for an acrylic or poly - urthane spray or dip lacquer if you really want to resist of tarnishing problem for a very long time........for your information now many suppliers hav chrome free antitarnish even chemisorption antoitarnish can be used which is used for silver protection can be also used , but seems to be little costly.

Regards,

praveen kumar
Praveen Kumar




plating process supplier
Mumbai, India

^

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