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Aluminum coloring

I am wondering what chemicals change colors on aluminum.

Jeff
- Lakewood, Colorado
2002

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Anodizing dyes color aluminum. They are fairly similar to fabric dyes like Rit, but made for dying metal. But the thing is, they have to be applied at the right point in a finishing process called anodizing. First the process strips off any soil and the naturally forming oxide finish, then it removes any non-aluminum alloying materials from the surface,then the anodizing step per se forms a honeycomb like structure on the surface of the aluminum, then the parts are dyed and the honeycomb pores absorb the dye, then the walls of the honeycomb are swelled by a sealing process that locks the color in.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002