Summary for zinc plating is low quality Discussion
zinc plating is low quality only when the shop is low quality, and the thread’s main advice is that zinc itself is not inherently the problem. The questioner, a small manufacturer of specialty tools, described recurring issues with outsourced yellow zinc: long lead times, cost, adhesion failures, bubbling, inconsistent color, lost parts, and missed deliveries, and asked whether a different coating could be run in-house on mild steel with minimal dimensional change and some corrosion resistance. The source text notes that good zinc plating shops and top-quality zinc plating are available, so the first option is to improve sourcing rather than assume the process is bad. It also points readers to books on zinc plating, including Ted Mooney’s cited resources, implying that in-house zinc plating may be feasible for a small shop if properly set up. No single alternative process is named in the excerpt.
Q. We are a small manufacturer producing specialty tools for industrial customers. We end up with a part mix that is fairly low quantity but lots of variety. Mostly mild steel and small enough to hold with one hand. Historically we’ve had them plated with yellow zinc, but it’s been a real pain.
Hard to say which is the most painful issue but, lead time, cost, adhesion, bubbling, color, consistency from one week to the next, lost parts, missed deliveries, and more.
Considering that we spend $20-$30k per year for this, I’m wondering if there might be a plating/coating process we could do in-house and avoid some of those issues.
So…
Looking for a plating/coating process for mild steel. Needs to have at least some corrosion resistance. Needs to be reasonably robust that it doesn’t come off under handling. Minimal dimensional change (maybe 1/2 thou ok) and most importantly, the process needs to suitable to add to a ~10 person shop.
So, is there a different process that might be suitable for our needs that we could run in-house?
-Thanks
SUGGESTED ZINC PLATING BOOKS
for Shops, Specifiers & Engineers
“Electroplating of Zn-Fe, Zn-Co & Zn-Ni” by V Narasimhamurthy (2020)
from
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Amazon
“Zinc Electroplating” by Muralidhara & Venkatesh (2018)
from
eBay,
AbeBooks, or
Amazon
“Alkaline non-cyanide zinc plating with reuse of recovered chemicals” by Jacqueline M. Peden (1994)
from
(U.S. EPA)
“Zinc Plating” by Herb Geduld (1990)
from
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“Tin-Zinc Alloy Plating” by Tin-Zinc Alloy Plating (1952)
from
eBay, or
AbeBooks
“Zinc Cyanide Plating Solutions” by William Blum (1921 Classic Reprint)
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“The Composition and Comparison of Zinc Electroplating Solutions” by John Elder Pyron (1917 Classic Reprint)
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Amazon
(as an Amazon Associate & eBay Partner, we earn from qualifying purchases)
Denny Esterline
Engineering Lead – Tucson Arizona
November 15, 2024
A. Hi Denny, I understand your frustration. However, $20-$30K per year, even if it seems a lot to me and you, is nowhere in the range of what would be needed to justify bringing a process in house. And if you do in-house plating the regulatory issues alone will cost that much, while driving you crazy.
The basic problem is that painting or powder coating is probably inappropriate for tools, so you need a metallic process, and zinc plating is the least expensive metallic finish, so it is often associated with junk — and there is a lot of competition at the low end, with quality often suffering.
What probably needs to be done, frustrating as it is, is to find a plating shop who will consistently deliver quality on time. You may or may not have to pay more, but there are such shops.
Alternately, you might search for a shop offering zinc alloy plating (zinc iron, zinc cobalt, zinc nickel). These finishes are somewhat more expensive than plain zinc and somewhat more corrosion resistant, so specifying such would at least eliminate some of the bottom-of-the barrel plating shops from the potential vendor list.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
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