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  for Metal Finishing since 1989
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Cleaning anodized aluminum

We are looking for ways to clean anodized aluminum on an exterior application. I have been told anodized aluminum can oxidize no further but this appears to be the effect we're trying to remove.

LAURIE S DAVIS
1996

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Hi, Laurie. Anodizing can eventually corrode, especially outdoors.

Anodizing, believe it or not, is nearly glass clear. It is even used on highly polished reflectors such as most street lights and many dentist's lights. So I don't think you would want to remove the anodizing. But unfortunately, anodized surfaces look like a honeycomb; and if they are not well sealed they readily absorb dirt into the honeycomb that is very difficult to remove.

Aluminum cleaners work at least somewhat, but I think you're going to find it hard to get a bright and durable finish put back on that aluminum in place.

One possibility is to strip the anodizing, polish the aluminum to a good shine, and clear coat it -- but let's see what additional comments your letter gets. Good luck.

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

Can exterior anodized aluminum siding be cleaned, primed and repainted? My siding was installed 28 years ago, but the finish is now beginning to run and discolor the stonework. Does anyone out there know of some way to refinish this product?

J collins
- Canada
1996

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Hello, J. You can paint anodized aluminum siding. Scrub it well and use a primer for metal, and I think you'll be satisfied. Good luck.

Regards,

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

To get off anodized finishing, Easy Off oven cleaner ⇦this on eBay or Amazon [affil links] works well. it contains a solution based on lye, so I suppose lye itself would work if of a lesser concentration.

Allan Stewart
- Worcester, Massachusetts
2000