Summary for hard chrome plating zinc Discussion
Hard chrome plating of zinc based metal is discussed as an unusual and generally poor fit, especially for zinc diecastings. Danny Masalonga asked what chemicals and methods would be used to chrome zinc-based metal. Ted Mooney, P.E. replied that readers should first review the FAQ “Introduction to Chrome Plating” and then Guffie’s book “Hard Chromium Plating” for process details. His main caution was that hard chrome on zinc diecastings may not add much wear resistance because the zinc substrate is too soft to support the hard chrome layer without cracking. He compared it to using eggs as an abrasive: the shell is hard, but the overall assembly may not hold together. In a follow-up, Steve Rockow agreed that it is a strange material choice for a cutting tool.
Q. I am an employee of a plating shop that my brother set up late in the 80’s. I have encountered customers asking if it’s possible to chrome zinc based metal. And so, I used the internet and found this site. I like to know if there is, and if so, what chemicals are to be used and how. I would appreciate it very much if you can help on this matter. Thank you.
Danny Masalonga
employee – San Pedro, Laguna, Philippines
October 17, 2011
A. Hi, Danny.
Please see our FAQ: “Introduction to Chrome Plating” for some general info on the subject. Then you could move on to Guffie’s “Hard Chromium Plating” book for process details. Hard chrome plating of zinc diecastings is unusual because the very hard surface might accomplish little in terms of adding wear resistance when the base is so soft that it can’t properly support the “shell” from cracking. It would be a bit like trying to use eggs as an abrasive or blasting medium; the shells are hard, but the assembly may not hold together. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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October 17, 2011
I have a zinc die cast paper punch. I need to extend punch life from 1000 to about 2500 cycles. There’s no question the paper is rounding off the edge of the punch and inducing a burr. I understand the substrate is very soft. But, the loads are relatively low. Is there any hope hard chrome could do this? Would it flake off in a size noticeable to the naked eye?
Steve Rockow
– Maumee, Ohio, USA
January 31, 2012
Hi, Steve. I don’t think it’s impossible for this approach to work. In fact, it will probably outlast your life cycle a hundred fold. The chrome will not flake off of a properly prepared substrate, and you are probably right that the loads are light.
But it is hard for me to picture how chrome plated zinc die-cast punch pins would be better and more economical than chrome plated steel pins or nitrided pins.
Hopefully your inquiry will draw additional responses. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
January 31, 2012
Hi Ted,
Thanks you so much for answering my question.
I agree. It’s a strange material choice for a cutting tool.
Thanks again.
Steve
Steve Rockow
– Maumee, Ohio, USA
February 3, 2012