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Anodize almag 35

How do you black anodize with 99 to 100% good with no leaching spots?

Jeremiah Little
- MO
2005

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2005

Any chance you'd be willing to clarify your question? Also, what is happening and being done with your parts now - that information is important too.

Thanks, Jim

Jim Gorsich
Compton, California, USA

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First of two simultaneous responses -- 2005

White speckles come from 2 common sources: (1) pits in cast and powdered metal parts which can be overcome by modified rinsing and extended neutralizing between the sulfuric anodize and the dye and (2) galvanic attack between titanium racks and the aluminum parts typically in the dye which can be overcome by using aluminum racks or with titanium racks using magnesium electrodes which will preferentially be attacked over your anodized parts. I'd love to look at the problem - can you post a photo or E-mail me one.

Milt Stevenson, Jr.
Syracuse, New York

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Second of two simultaneous responses --

Aluminum in the surface is anodized. Magnesium in the surface is not anodized. Many alloys come out with magnesium rich spots on the surface. These magnesium rich spots will never uniformly anodize. Certain alloys and some heat treatments are impossible to get 99% uniform anodizing.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

2005