Nickel plating

[aking]

Hello,
I recently had my vendor nickel plate 50 pcs of a 22 ga crs part we make. We inserted zinc coated hardware and shipped the parts to our customer. Within a week the cust called complaining about tiny rust spots on the parts. I am trying to get to the root of the rust problem, but my vendor is not helping. They believe it is because we inserted zinc hardware after the plating process. I understand the process of galvanic corrosion. The rust is not around the hardware but spread randomly across the parts. My GM believes the plater did not rinse the parts properly prior to plating them. What do you think?

[48Buick]

From my experiance the problem is in the process your plater used.
If he did not put a strike plate on the part or plate with the bright nickel for at least 40 min rust will show through. You can use regular bright nickel as a strike prior to copper, but if you use it as the only plate you have to put it on thick to keep the oxygen from getting to the base metal (most likely steel?) I belive this is because of the nickel chloride in the solution. I have had this happen also.
Sad thing is the only way to rid the parts of it is to either clean and strike plate over the existing nickel or clean, activate and build up the existing nickel for 30+ min.
Most likely your vendor doesnt want to redo the parts and therefore wont
Help you. Rework is a pain, but sometimes necessary.
48BUICK

[48Buick]

Oh.....one other note I forgot...If you have zinc and nickel together the zinc will destroy itself lonnnnng before it causes any problem with the nickel.
Sound like you understand the corrosion process so you know Zinc is a sacrificial metal and nickel is way up on the nobel list from zinc.
Hope this helps you get a better footing on the problem.
Let me know if I can assist any more.
48BUICK