No passwords, No popups, No cost
we earn from your eBay & Amazon purchases

Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Adver-
tise
Help
Wanted
Current
Q&A's
Site 🔍
Search
curated with aloha by
ted_yosem
Ted Mooney, P.E. RET
- Pine Beach, NJ
finishing.com -- The Home Page of the Finishing Industry


  pub
  The authoritative public forum
  for Metal Finishing since 1989

-----

TARNISHING OF ZINC PLATING AFTER HEATING




OUR COMPANY IS MANUFACTURING METAL HOOKS. SOME OF THE HOOKS ARE CHROME PLATED AND SOME ARE ZINC PLATED. IN ZINC PLATED HOOKS WE ARE GETTING SOME PROBLEMS. THE HOOK BEFORE FITTING IN THE PLASTIC HANGERS ARE HEATED AT THE TIP. THIS IS WHERE THE PROBLEM BEGINS THE AREA ABOVE THE HOOKS GET BLACK OR THE PLATING IS TARNISHED IN THE AREA WHICH MAKES THE ZINC PLATED HOOKS UNACCEPTABLE BY THE PARTIES. COULD ANY SUGGEST ME SOME REMEDY ON THIS PROBLEM.

KIRAN PAMKAR
MANUFACTURERS OF METAL HOOKS FOR PLASTIC HANGER - BOMBAY, MAHARASHTRA, INDIA
2003



2003

Mr. Pamkar,

This may help.

1) Zinc Plate after blue passivation cannot withstand temperatures exceeding 55 centigrade. any higher and the film can degrade.

2) Hanger manufacturers mound the hanger with hook in place, rather than heating the hook and inserting it into a hanger.

3) Another possible reason for black color on heating could be the inclusion of organic impurities in the zinc deposit. It can help to run a carbon filter every 200 hours worked.

4) Hooks are best not heated.

Regards,

asif_nurie
Asif Nurie [deceased]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016



Dear Mr. Nurie,

In the hangar hook business they use a candle to heat the tip of the hook and twist it into the moulded hangar. Production rates fall once they try moulding the hook along with the hangar.

I suggest a zinc iron black passivation that will not discolor the hook tip on a candle flame.

Khozem Vahaanwala
Khozem Vahaanwala
Saify Ind
supporting advertiser
Bengaluru, Karnataka, India
saify logo
2003




(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:

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


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