Zinc Nickel vs Brigh Zinc

[tnkayaker]

I am looking for data that compares the salt spray results of zinc nickel with an iridecent chromate conversion with that of bright zinc. The questions I'm trying to answer are how much better is zinc nickel than bright zinc and will zinc nickel stand up to immersion in water over a 2 year period? Any help would be greatly appreciated.

Erik

 

[TVP]

A good place to start is information from engineering standards like ASTM B 633 for zinc plating and ASTM B 841 for zinc-nickel plating. For a 5 micrometer coating of Zn or Zn-Ni, the corrosion requirements are as follows:

Zn: no red rust after 96 hour salt spray test
Zn-Ni: no red rust after 500 hour salt spray test

You can also find good information from the websites of better plating companies. I have found the following to be particularly good:

http://www.modernplating.com/corrosion.html

http://www.surtec.com/Publications.html

http://www.macdermid.com/industrial/zinklad/index.html