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Electroless nickel plating on already plated parts

Our company received electroless nickel plated parts on which the plating thickness does not meet the requirement on the drawing for the part (thickness spec is .001 inch, plating is between .0004/.0006) The parts are machined from 4140 steel, each weighing about 150 pounds. It will be MUCH more costly for us to strip and re-plate as opposed to plating over what is already there. The plating on the parts looks great, it is simply not thick enough. Is it safe/possible to ENP over already plated parts, or is stripping and re-plating the only way to go? Thanks in advance.

Andy Lamb
sales engineer - Cleveland, Ohio
February 3, 2010

Strip and replate. It will pay off

Guillermo Marrufo
Monterrey, NL, Mexico
February 4, 2010

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February 5, 2010

If the parts do not meet the spec on your PO, send it back and have the plater fix the problem.
If the PO did not specify the thickness, replace the person that did the PO.
If this was done in house, Mgt needs to ask why they missed the amount. Wires or razor blades are wonderful ways to check plating thickness before removing the parts from the tank. Plating thickness is easy to control by qualified platers.

What the previous reply did not state is that it is difficult to activate any nickel flawlessly and EN is extremely difficult to activate flawlessly. A very very low probability of success by a plater that can not control thickness.

James Watts
- Navarre, Florida