Defects in silver plating: blisters, nodules, and pits

A. Hello Chua. The short answer is that the plating process is defective (although the plating shop might perhaps validly claim that the material is not suitable for plating). As a customer, though, there is usually only so much you can do to fix the problem, but it starts by simply insisting that the parts are not acceptable if they blister or if they have nodules and pits.

The plating shop presumably has years of experience at this, so realistically you're not going to learn enough from an internet posting to be able to improve their process for them. Your usual option is to tell them they must do better, and then locate another supplier if they don't. But I suppose you could insist that they retain a plating consultant. You could get a few books on electroplating from our "must-have booklist" (if you don't have them already) which probably would help you acquire a deeper understanding of the technical issues causing some of those defects.Good luck.

Hi Ted,

Thanks for the reply and pointers.

What you have said is true; it is not possible for a customer to know enough to resolve the problem. I have encountered more problems recently like poor adhesion, peeling off of silver plating, etc.

As a customer, I wish to play my part to support the Supplier in achieving Quality Product. I am even thinking of introducing PMP and FMEA to help Supplier monitor and document processes for improvement.

Q. It has not been easy to locate a good silver plating supplier, especially for our product which requires two different plating areas but with same thickness. Presently rubber masking has been used but leakage occurs. Any good suggestions to prevent leakages? We are supposed to plate two different size internal diameters, with min. plating thickness of 25 micron. Internal diameter have been machined and controlled at tolerance of ±0.012 mm before plating, ±0.017 mm after plating.

Please assist. Thanks.

Regards

A. Hi Chua. As a general rule, plater's tape or stop-off lacquer will provide a more leak-free masking than a rubber seal because they adhere. But I don't know whether those are applicable to your production situation.

Regards,

A. This defect is usually called "Burning" which is caused by variation in flow of current.You need to set a proper rectifier to minimize current fluctuation.

A. Hi Hemant. I'm not sure if you are starting onto a different problem on the same parts here, or clarifying your previous posting, but I would have to agree with Rahul that the previously posted pictures reflect burning (or possibly roughness from unfiltered particles), not porosity.

Assuming this is an additional problem, can you tell us a little about the cleaning, activation, zincating, underplate if any, and silver plating process? Do you do the plating in house?

Regards,