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Need input on ways to tint, dye and seal aluminum articles

I'm attempting to do "anodized" coloring on aluminum to make small jewelry components. I used a technique published in a book for kitchen-table anodizing: soaking the piece in a lye solution for a few minutes, then dipping in household fabric dye. It sort of works...if you want muted, worn-looking antiquish sorts of mild tints which happens to work for my purposes. The real problem: The tinting (which the book implied would be permanent) rubs off with minimal effort or can be scratched with a fingernail. I need a way to seal the piece with a durable, long-lasting, commercial-quality lacquer or sealer to make a wearable piece. Any suggestions for improvements to either the coloring or sealing process would be greatly appreciated.

Michael G. Axtman
- Beaumont, California, USA
2002

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You're not really anodizing your parts with that lye--you are only etching them. You can try putting your parts in boiling water for 10 minutes, which is one way of sealing aluminum; but in view of the fact that you haven't really anodized them, I'm not confident. See what happens, though, it just might work.

The step you are missing is the actual anodizing process. That may be what you have to do to get freedom from ruboff. On anodized parts the dyes are actually down at the bottom of a deep honeycomb where they are readily absorbed and can be protected by closing the pores with boiling water.

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