Ask the Expert Question-and-Answer Archive
(Hard Chrome Plating)

by Randy Taylor, Advanced Tooling Corporation.
November, 2006

Agitation in Chromic Acid Baths

Q. During hard chrome plating process, we have agitated the solution by mechanical. But there is no improvement in product quality or speed of the electrolysis. Is it true that agitation will not improve the quality and speed of the electrolysis?

A. Yes, that is true in hard chrome as a general rule. There are exceptions, particularly where fresh chrome solution can not flourish, plating solution may become depleted and plating rate will slow.

Many factors affect quality and speed of electrolysis. Most important, is the use of well designed plating racks and fixtures and properly sized "conforming" anodes. Good tooling can usually overcome other variables such as, old equipment or plating bath, temperature variations or cold spots, bath contamination, or a lack of experience and training.

The tools one chooses to use in hard chrome plating can make the difference between slow plating, or a more desirable, and predictable rate of 0.0015 - 0.002 thick per hour and more, with or without agitation.

Q2. Thank you very much for your reply. On the other note, is there any reversable switches are available for etching operation in the same bath? Please let me know the companies that are dealing reversable switches.

A2. Reverse switches are often custom made for a specific requirement. They can get pricey according to size and amp capacity. Call the Darrah Electric Company out of CLE, Ohio and ask for John. They may have some items on the shelf, or will quote a price to manufacture. Good luck

Darrah Electric, Co. 216 631-9937 (business hours 8-5:00 EST)