Summary for za27 plating Discussion
ZA-27 plating is discussed as a special case because its high aluminum content makes standard zinc diecasting pretreatments unreliable. Joaquin M. asked what extra steps are needed beyond solvent degreasing, and Steven M. asked about corrosion-protective coatings, including plating, anodizing, and chromate conversion, for ZA-27 and similar ZA-12/ZA-8 alloys. The most detailed answer came from an unnamed contributor in 2020 responding to Steven Baynham’s nickel-plating problem: they said ZA27’s 27% aluminum is likely why zinc-diecast processes are failing, especially the copper flash adhesion and blistering. Their recommendation was to treat ZA27 more like an aluminum die casting than a zinc one: avoid electrocleaning, use only a mild non-etch aluminum cleaner, follow with a mild acid dip, then zincate before the copper strike. Baynham replied that this matched his thinking and that he would discuss the process with the plater and possibly seek another shop.
Q. Die casting Alloys ZA-27, which has the highest aluminium, presents special considerations for plating– for example degrease with solvent. What other special considerations are there for plating application over ZA-27 die casting Alloys? Thanks.
Joaquin M.
– Medellin, Colombia
1999
Q. Concerning ZA-27 Die cast alloy:
We are currently looking for an acceptable method of coating the ZA-27 parts in order to protect against corrosion. Do you have any suggestions? What kind of plating? Is there an anodizing method that works? How about chromate conversion? Also, do you have similar experience with ZA-12 or ZA-8?
Thanks,
Steve M.
Steven Macri
– New Hope, Pennsylvania
2000
Ed. note: Thread 18416 addresses anodizing of ZA-27.
Need nickel plating service onto Zinc-Aluminum alloy
RFQ: I am looking for a shop that can plate nickel onto ZA-27. looking for larger volumes of small parts to be plated.
Jim Portmann
OEM – Delano, Minnesota, USA
September 29, 2009
Ed. note: This RFQ is outdated, but technical replies are welcome, and readers are encouraged to post their own RFQs. But no public commercial suggestions please ( huh? why?).
High Phos Nickel Plating on Zinc ZA27
Q. I have a situation where we are using a Zinc ZA27 part that needs Nickel Plating for corrosion/reactive resistance to E85 fuel. We have been using High Phos Nickel plating for many of our zinc parts (Made of ZA3 and ZA8) but this particular part made of ZA27 has been giving us issues. The part is copper flashed first and the copper flashing does not seem to be adhering correctly. The final part after Nickel plating shows blistering in many locations. Any suggestion on how to mitigate the issue will be of help. I am the specifier of the product not the plater.
Steven Baynham
– St. Louis Missouri
March 30, 2020
A. Hi Steven.
ZA27 contains 27% aluminum which is surely why processes designed for zinc diecastings aren’t working well. Although I don’t actually have any experience with this alloy, I am pretty confident that treating it as an aluminum die casting rather than a zinc one will work. In other words no electrocleaning (only a mild non-etch aluminum cleaner), followed by a mild acid dip, zincating, and then the copper strike.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
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April 2020
Thanks for the response. That is exactly what I was thinking but I am not the plater. The plating company I am using now has been very secretive about their process which I understand. I will follow up with them again and begin talks with a new plating company as well.
Steven Baynham [returning]
– Pacific Missouri USA
April 7, 2020
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