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Q&As since 1989


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Black without anodizing?

The only reason I anodize my aluminum parts is to get a black finish. Can raw aluminum be dyed black without anodizing? And if so is that something I can do in house without plating equipment?

Karl miller
- Greenwood AR
1999

Karl - Yes, aluminum can have a black coloring imparted without anodizing. You don't mention any wear requirements or environmental factors, but a viable alternative may be room temperature black oxide. This process is very easy to set up in-house and requires very little equipment. Good Luck.

Dan Brewer
chemical process supplier - Gurnee, Illinois
1999

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If you were hoping to be able to just set up a few crocks or buckets you'll probably be disappointed with your results. To get a rich, even finish you'll need a complete Aluminum cleaning line. Also, black chromates scratch easily. Any abrasion will remove the finish quickly.

You didn't say what type of Al you have but there are blackening solutions for some alloys. We have our best results on 6061, although we have tried several other alloys. If you look in the Metal Finishing shop guide you can find a few vendors. As far as doing it in house: If you already have a finishing operation it probably won't be much trouble to do it. If you are starting from scratch then you may want to get the services of a consultant to get you set up. Due to the cleaning and etching chemicals, in addition to the blackening solutions, you'll probably need several state and federal permits (if you don't already have them). You'll also need to have a way to treat the rinse water from the operation. I would think a cost justification analysis could be done to see if it would be beneficial to put the line in.

Jim Conner
Anoplex Software

Mabank, Texas USA

1999