No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

Zn-Ni alloy stripping




In stripping of electroplated Zn-Ni deposit, we alway found black ash on surface and this ash can only be removed by rubbing. Is there any cleaning method can remove this black ash?
Thank you for helping.

John Su
Engineer - SHENZHEN, CHINA
February 14, 2008



You haven't told us about your situation, John, so that we can guess what the black ash is and how to prevent it or remove it chemically. How do you strip the parts, what are they made of, is the stripping electrolytic, what is the solution, is it done on racks, in plating barrels, or in bulk?

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February , 2008



February 17, 2008

Originally we would like to strip off the bad quality Zn-Ni plated (13-14% Ni) articles (Rack) by 50% HCl, but we found that the surface was covered by a layer of black ash even long time dipping in the acid. Soak cleaning and Electro-cleaning (anodic) seem no help to remove this black layer. The only way we found to remove this layer is by rubbing and so we would like to know if anyone can suggest us an alternative method to remove this layer easier.
Thank you.

John Su
- China



I have only a hunch, not facts, but I suspect that the plating is stripping off easily but in the course of doing it you are causing the substrate to get smutty by too heavy an acid treatment. Try reducing the concentration or immersion time.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February 21, 2008




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"