Carburetor Body Finish Improvement
We are in the business of manufacturing two wheeler carburetors in India. Presently we are working towards improving finish of our carburetor bodies (Zinc pressure Die cast) by way of passivation.
What should be the best pre-passivation, passivation and post passivation process to bring a silky smooth finish with a slight glow on our component. It should be able to pass 48-72 hrs salt spray test.Kamal Wadhwa
auto components - Faridabad, Haryana, India
Dear Mr Wadhwa:
Zinc diecast carburetors can be passivated directly as possibly you are doing and their finish is to a point acceptable.
A second possibility is to plate the carburetor body with Alkaline Cyanide free zinc which is the preferred solution on account of its very high throwing and covering power . it covers the deepest recesses and passivates very well to provide a uniform Blue bright or a white finish that will last for anything from 48 to 96 hours salt spray.
I am reasonably sure platers in FBD who are aware of Alkaline cyanide free zinc will be able to give you the right answer. QC and Plating at Yamaha Faridabad too have plenty of inputs on the subject.
Asif Nurie [dec.]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016