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topic 59475

Black spots on Nickel/Chrome plating

November 30, 2013

Q. Dear Sir,

We are a nickel/chrome plating company that recently suffers from black spots on the nickel/chrome plating.
The spots become visible after about 24 hours and occur on about 10% of the pieces on the same rack (different location on the rack each time).
We've cleaned all anodes, changed the pre-treatment multiple times ... but we can't seem to find the right solution to avoid these black spots.

They are black spots that are difficult to see in a normal environment, but very visible when you let the chrome reflect on a white paper.

I was wondering if you've seen this problem before and if you would have suggestions/solutions for our problem?

The new test that we are going to do now is adding ACTANE 70 ^ KT (product from Enthone) into the activation process.

I have offered photos of the black spots.

Kind Regards,

Megs Tests
- Gent, Oost-Vlaanderen, Belgium

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Plating Process Engineer [Wenatchee, WA]
Plating Supervisor [Chicago]
Plating Quality Inspector [Chicago]

December 2, 2013

A. Megs,
I am sorry, I do not see the photographs but one might look into two possibilities. 1. It would be good to check to be sure the incoming material is not defective in terms of pits. 2. One might add some hot and cold rinsing to help clean out the pores. This can be done during pre- and post-processing.

blake kneedler
Blake Kneedler
Feather Hollow Eng. - Stockton, California

The 5 photos from the .pdf file can now be viewed by clicking here

December 5, 2013

A. Hi,
This problem of black spots which you are facing seems related to base material defect which you might have failed to notice during pre cleaning stage and the same is appearing over a period of time once plating is completed.

All the best,

- Bangalore, Karnataka, India

December 5, 2013

A. Please check layer thickness
Could be too low

Reasons mainly poor contact
distance to anode
Any other

Just a possibility

Daniel Hernandez
- Bucaramanga, Santander, Colombia

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