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Passivation problems in mechanical plating

August 16, 2009

Dear Sir,

I am mechanical plating applicator in india. The main problem I am facing is of passivating the mechanically plated products to increase the salt spray resistance. As done in the case of electroplating, we dip the electroplated products in the solution of hex or trivalent chrome (standardised solution) followed by a wash in water and then a sealer. I am following the same steps but couldn't get the desired salt spray life. Please guide.

Secondly we also tried zinc/tin mechanical plating by adding the zinc and tin powders in the plating barrel alternately to increase the SST but couldn't get the desired results. We tried to coat up to 20 micron coating thickness. The target is of 1000 SST(RR). Please guide.

Manjeet Khosla
Plating shop employee - India

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Your first step should be to contact your suppliers - whoever supplies you with Starter (or Surface Conditioner), Coppering Formulation, and Promoter (Accelerator); you should also contact your supplier of your chromating/passivating solution. They should be able to solve your problem.

Tom Rochester
CTO - Jackson, Michigan, USA
Plating Systems & Technologies, Inc.


August 20, 2009

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August 22, 2009

My suppliers are not able to solve this problem. I am looking forward for your support.

The passivations and sealers we got it and tried from different suppliers but the resultant is same which is no salt spray protection.

Thanks and regards

Manjeet Khosla

Manjeet Khosla
- Ludhiana, India

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Hi, Manjeet. I think the implication of Tom Rochester's reply was that if your suppliers cannot help you solve this problem, then you need to find new suppliers who can. There is a lot involved, and we are talking about proprietary chemicals --such that the readers are not even going to know exactly what formulations you are using, let alone how to tweak the formulation for greater success. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 23, 2009