Summary for black zinc finish issue Discussion
Black zinc cosmetic finish issue: a supplier of large steel washers for a lighting manufacturer says the customer is complaining that the black zinc is not truly black and shows rainbow-like colors on the surface. The part is a cosmetic component, and the supplier has already tried to minimize the problem and rework the parts without success. The thread excerpt shown here contains only the question, so no technical diagnosis or remedy is provided in the visible text. The issue is framed as a finish-quality complaint on a 1.5-inch OD, 1/10-inch thick washer, with the concern centered on appearance rather than function. Ted Mooney’s site branding appears in the excerpt, but no answer from him or others is included in the provided text.
2003
Q. Dear Sir, My company is distributing-supplying a Steel washer in Black Zinc to a lighting lamp manufacturer. The washer is a large
1.5″ outer diameter with a 1/10″ thickness. This is a cosmetic part for our customer.
The customer have been complianing that the black zinc is not perfect black and has rainbow like colours on the surface of the black zinc. We have tried to minimise and to prevent this and rework but has not been successful.
Can someone help me suggest alternative coating, plating or painting, or other process that we should take note of to have a perfect black colour steel washer. I welcome any known source or referral to solve these cosmetic problem.
Thank You. Ronnie Tang
Ronnie Tang
EXIM & MFR ENTERPRISE – Singapore
A. My suggestion, Mr. Tang, would be to consider switching to zinc-iron plating. It readily accepts a stable black chromate.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
2003