Metal finishing Q&As since 1989

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Lacquering passivated fasteners

2004

Dear all of you,

In our company,we have been involved in the manufacturing of ground support equipments for aircrafts. At present we are green passivating the fasteners used. my question is, will it be 100% corrosion free if I go for an extra lacquer coat (2 microns).

Thank and regards,

Manickaraj Silas
engineer - Coimbatore, Tamilnadu, India

Mr Silas,

The corrosion resistance of Green Chromate will increase if a suitable lacquer is used. If the fastener is plated in a Zinc Iron alloy bath the corosion resistance can double and go up to Salt spray failure of 450 Hours before white rust. I will suggest you look at the standards of Quality expectation from you customer first, then the real answer in terms of Salt Spray Test life will be clear. Thereafter you can select the right process.

Regards,

Asif Nurie [deceased]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016
2004