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Anodizing 1100 Aluminum thru 1 mm thickness (possible)?

Is it possible to anodize piece of 1100 aluminum as deep as 1 mm? I'm using a 100 mm x 100 mm x 1 mm thick aluminum. I run a gross check process (not maintaining the temperature) of acid anodizing process for 7 hours, but still I'm not about to anodize the complete thickness of 1 mm. Can anyone help?

Ron Ng Ah Hock
hobbyist - Bagan Serai, Perak, Malaysia
February 17, 2008

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Pleased explain your full situation, Ron, because what you are describing bears little resemblance to conventional anodizing so I find that I can't understand the question. But even hardcoat anodizing is rarely ten percent of the thickness you are looking for.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February 22, 2008

I'm referring to anodizing 1 mm thick, which will enable separation of one piece of Aluminum into 2 electrical terminal for small electrical current application for decorative purpose, e.g. low power LEDs decoration (more on hobby and good challenge too :)). I know normal anodizing will only be as thick as less then 50 um, is the thickness is a function of time? which mean, if I would have anodize the same piece for a week, I will finally get the anodizing thru the 1 mm thickness.

Ron Ng Ah Hock
- Bagan Serai, Perak, Malaysia
February 24, 2008

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No, you won't get a 1 mm coating with conventional sulfuric anodizing. I've produced/seen functional anodized coatings in the 200 µm range, but not much higher. Yes, anodizing thickness is partially a function of time, but it's also a function of current density. As you anodize aluminum, you are also dissolving the substrate, which is referred to "the rate of dissolution." Eventually, the dissolution rate ends up being higher than the rate of which you are applying the Al₂O₃, and the coating ceases to grow.

Marc Green
anodizer - Boise, Idaho
February 26, 2008