Letter 907

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We want to zinc plate + black oxide seal some powder metal (MPIF 35, F-0008-25) parts. We need the black to look good esthetically and not fall off in our hands. We need the parts to pass a fifty hour salt spray test. The parts are small, about on cubic inch, and all have an 1/2 inch through hole.

Grant Bryant -
Indiana Mills and Manuf., Inc.

I have never heard of black oxide on zinc. It may be done, but I doubt it. Are you asking for a black chromate on it?

James Watts - Fl

Zinc and black chromate should easily pass a 50-hour salt spray test when applied to a suitable substrate. However, depending on the quality of the powdered metal parts, they will probably be very porous, and basically unsuitable for plating onto. I'd suggest that you may need to investigate vacuum impregnation with a supplier to prepare the parts before plating.

 
Ted Mooney, P.E. - Finishing.com Inc. - Brick, NJ

Sir: I would like to know more about the market on zinc powder, that is where I can purchase it at a wholesale price in quantities of a 100 lb. pail. Please send any info. you may have.Thank you.

Arthur Trujillo
- Amarillo, Texas 79102

Message for Mr Grant Bryant

Vacuum Impregnation is an important prerequisite prior to any kind of plating operation for a sintered component. Vacuum Impregnation helps to seal the porosities in the components , so that the plating acids do not pose a problem of leaching after the plating operation is completed .

Best regards,

Mr Saibal Sen / Mr Probal Sen
Pune 411007 , India

I would like to economically plate 1100 series aluminum to a black conductive finish. The part is an impact extruded cup housing 1" dia .75 tall with .060 wall thickness. Quantities would be approximately 10 to 50 K annually.

Joe Donahue
- Hingham,Ma

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