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What type of plating should be used on steel before powder coating

2007

Hi,

The company I work for produces test systems for the electronics industry. The outside panels and frames of our systems are made of CRS and are plated with yellow chromate over zinc. We currently paint these panels and frames in-house but our one painter has left the company so we are looking into powder coating instead, using an outside vendor. The entire system is not painted; we mask off the edging around the door openings and do not paint the interior. After powder coating and curing at 400° F, will the un-powder coated surfaces corrode or will the chromate hold up. If it will corrode, how should we plate these parts before powder coating to achieve good adhesion with the powder coating and provide good corrosion resistance for the un-coated areas?

Thanks,

Mitchell Oachs
Customer - Minneapolis, Minnesota, USA

You may try to optimize your chromating process time to 20~30 sec. Per theory, the chromate will have maximum protection if the chromating process is done correctly. The maximum allowable for chromate to break down is 200 °C. It should be enough for you to use in powder coating. The reason for the breakdown is the chromating process is not done at correct timing.

John Corr
- China
2007