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Electroless Plating and Coating

Hi, I am looking for the method of electroless Zn plating. I am really wanted to know some more details of electroless coating so any help will be GREATLY appreciated.

Jagadeesh Kumar M.
- Bangalore KARNATAKA India
2000

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I was not aware that zinc could be deposited in an electroless process. Are you sure you don't mean electroless nickel? Electroless nickel (EN) is a common process.

Tim Neveau
Rochester Hills, Michigan
2000

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'Electroless' is an unfortunate word in electroplating because it means different things to different people. To most platers and others in the trade, 'electroless' means autocatalytic; that is, the surface of the metal being deposited (like nickel) or the metal you start the plating on (like steel) acts as a catalyst that causes the complexing solution to decompose and continue to deposit more metal.

To students and people not in the trade, 'electroless' means 'immersion plating'. For example, copper sulphate ⇦ this on eBay or Amazon [affil links] will deposit copper onto steel in an immersion deposit or electroless way: an atom of iron dissolves into solution and an atom of more noble copper plates out in its place. To platers, immersion deposits are largely worthless because they lack adhesion and they are self limiting (as soon as an atom of copper covers the steel surface, the copper plating ceases because there is no more exposed iron to go into solution).

So, in one sense, electroless zinc certainly exists. The familiar alkaline 'zincate' solution we use as the first step in electroplating onto aluminum forms an immersion deposit on the aluminum. There may be autocatalytic zinc solutions, but I'm not familiar with them either.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2000