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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Hard chrome plating of zinc based metal
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 Masalongaemployee - 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
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
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
- Maumee, Ohio, USA
February 3, 2012
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