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Electroless plating starts fast, then slows to a stop

March 2, 2010

Hi dears;
I work in a ball valve manufacturer we plating all of parts that use in ball valve.
After plating start, rate is very good but suddenly plating stop.
What's the matter?

ALI KHODAEE
plating shop employee - TEHRAN, IRAN

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First of two simultaneous responses --

EN baths have to be "poisoned" or calmed down to control the catalytic reaction and avoid spontaneous decomposition. Bare ferrous surfaces are generally far more active or catalytic to the reaction than EN itself. So, it is normal to have a higher speed of reaction initially. Once a layer of nickel has formed, that speed slows down but it should not stop. If it does, it means your bath is out of balance. If you are buying from a dedicated vendor ask him. If you are using an empiric formula you are on your own. G. Marrufo-Mexico

Guillermo Marrufo
Monterrey, NL, Mexico
March 4, 2010

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Second of two simultaneous responses --

Ali,
What type of electroless plating are we talking here? Is it electroless nickel?

Mark Baker
process engineer - Malone, New York
March 4, 2010

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April 7, 2010

Yes it is electroless nickel.
Please give me more explanation about out of balanced bath.
BEST REGARD'S

ALI KHODAEE
- TEHRAN, IRAN

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First of two simultaneous responses --

Chain reaction. That is what an electroless bath wants to do. Certain chemicals are added to calm that reaction down. The amount added is very critical. If you add just a little bit more the bath stops. Most of the time it can be reactivated. But again, if too much activator is added, the chain reaction may start again. Not easy. That is why patented or secret chemistries cost more and still people buy them.
If you cannot or do not want to afford a patented formula, keep trying. When you have succeeded, if you do, it would be perfectly honest for you to expect a profit or a commercial advantage in return for your effort and expenses.

Guillermo Marrufo
Monterrey, NL, Mexico
April 8, 2010

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Second of two simultaneous responses --

I hope I am not infringing on Mr Marrufo's reply over a month ago. As you probably know there are make up chemicals and chemicals you have to add as the bath plates out Ni. Bath make-ups have different agents like a reducing agent, stabilizer, complexing, and Ni metal. One of these is most likely out of balance. A mistake could have been made at the time of addition. Lab analysis should tell you where the problem is but after a month, I'm sure you have the problem under control.

Mark Baker
process engineer - Malone, New York
April 8, 2010

If you are using a proprietary solution, confirm the stabilizer addition in your solution. More stabilizer cause slow plating. Are you seeing any patch marks over plated components? Try dummying before actual plating

ANVER SULAIMAN
- Mysore, Karnataka, INDIA
April 29, 2010