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Electroless nickel (EN) suffers non-conductivity

We had some aluminum shelves electroless nickel plated. They came back with a yellow hue and were non-conductive. Any ideas?

Truman G. Glasscock
- Huntsville, Alabama
2003

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First of two simultaneous responses --

Does your electroless nickel plater also do anodizing?

Todd Osmolski
- Charlotte, North Carolina, USA
2003

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Second of two simultaneous responses -- 2003

Probably, an adhesion bake at an excessively high temperature oxidized the surface. Adhesion bake on aluminum should be at 375 F for non-heat-treatable alloys, or 250 F for heat-treatable alloys (MIL-C-26074 [on DLA]E, Classes 3 & 4, respectively). A straw colored tarnish suggests a hardening bake > 600 F, as performed on steel (Class 2).

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.

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The symptoms you describe indicate that the aluminum was not electroless nickel plated but rather it s anodized and dyed gold. Come back with more information. Electroless Nickel freshly plated, especially only after a few days WILL conduct. Anodizing is insulating.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2003