Zincate treatment for steel

"The Surface
Treatment &
Finishing of
Aluminium and
Its Alloys"
by Wernick, Pinner
& Sheasby

(note: this book is two volumes)

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A. Hi, Siji. Sorry, but I haven't heard of it. The only application I know of for zincate before EN is onto aluminum, per chapter 14 of Wernick, Pinner, & Sheasby .

Regards,

A. Siji, perhaps you would like to share with us your thinking on how and why a zincate process will be of advantage in coating either mild steel and stainless steel with electroless nickel. There are other proven technologies for doing so, but I, for one, am always willing to learn new arts and skills.

A. In my case the use of Geomet 650 zincate coating on my companies outdoor radio mounting screws and cover fasteners allowed us to endure 1000 hours of salt fog tests to a successful completion. Stainless steel is not perfect and at this extended test requirement we found many screws corroding and the corrosion affected powder coating at the interface to the housing allowing galvanic interactions that created extensive damage to the housing.
The Geomet 650 is a dip and spin process that is applied post fab of the screws or whatever part that may need additional protection. In the salt fog tests the screws would turn a white color as the sacrificial zinc was slowly consumed. Galvanic issues were no longer an issue.

Zincate

 Hi Jon. Thanks for the interesting input. We're having a semantics problem here, though: to me, Geomet and similar zinc flake dip-spin coatings would not be called "zincate"; to me, zincate is Zn(OH)₄^-2 typically used from solutions of 40-100 g/l ZnO and 400-500 g/l NaOH, and whose main use is in forming an immersion zinc deposit onto aluminum so that it can be electroplated or electroless nickel plated. Thanks again.

Regards,