Summary for metallic coatings removal Discussion
metallic coatings removal depends heavily on the specific coating/substrate pair, so there is no single universal method. In the thread, Ted Mooney explains that stripping procedures vary widely: copper from nickel would require different chemistry than nickel from copper. He says many removals use immersion or anodic treatment in an acid that attacks the coating much faster than the base metal, and gives examples such as cadmium, chromium, or zinc being stripped from steel with HCl or H2SO4. He also notes that some cases call for complexing chemistry, such as nickel removal from certain substrates using an anodic cyanide-based stripper. Mooney says he does not see a general pattern, but points to a useful table of stripping methods in the Metal Finishing Guidebook. The original question asked for references and procedures for metallic and inorganic non-metallic coating removal.
Q. I am interested in collecting information about different methods for coating removal as a part of my Msc research. I have found different references addressing the removal of organic coatings. But I was not able to find adequate references about the removal of metallic and inorganic non metallic coatings. I would be grateful if some body would help me find some reference or would brief me about the most used procedures for the removal of metallic coatings and the removal of inorganic non metallic coating.
Yahya Hamed
student – Berlin , Germany
2004
A. The removal of metallic coatings cannot be easily capsulized because there are so many metal pairings, and the removal procedure depends on both the substrate and the coating. Consider for example that the removal of copper coatings from nickel would obviously have to involve chemicals and procedures utterly different than the removal of nickel coatings from copper.
In many cases the procedure involves immersion or anodic treatment in an acid that rapidly attacks the coating but only attacks the substrate minimally if at all. For example, cadmium, chromium or zinc is removed from steel by immersion in HCl (or H2SO4). Some times a complexor is the way to go, for example, nickel can be removed from a number of substrates in an anodic cyanide-based stripper.
I don’t really see a useful ‘pattern’ , but there is a nice table of the methods to strip different coatings from different substrates in the Metal Finishing Guidebook.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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2004
Dear Mr Ted Mooney
Thank you for your kind reply.
Best Regards,
Yahya Hamed
– Berlin, Germany
2004