49045

Black Zinc is rusting and rubbing off  

June 17, 2008

We are luggage manufacturer, Now in India Mansoon season, We have recd. screws with black zinc from our supplier which after one week obs. with white rust/corrosion. And also if we rub screws on cotton surface it removes coating.

Avinash Patil
Employee( QA Dept.) - Nashik

Hi, Avinash. I'm not sure what your question is but, yes, the parts are defective and you must get the supplier to fix the process or find a new supplier.

Regards,

Ted Mooney, P.E.  finishing.com Brick, New Jersey

Hello Avinash,

You need to specify zinc-iron plating instead of zinc plating with black passivation. This is a far superior coating although not bright and glossy and zinc with black.

A still better alternative will be Geomet coating with a black topcoat which will outlast the life of your product without corrosion.

regards,

Khozema Vahanwala Saify Ind   Bangalore, Karnataka, India