Metal finishing Q&As since 1989

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How to Strip Anodizing Before Repolishing

Someone gave me some parts that are anodized in blue, I want to strip the anodizing off so I can get them polished. What inexpensive way can I do this?

Steve Oravec
- Marietta, Pennsylvania
2001

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The best way is to take them to an anodizing shop which will have a hot chromic-phosphoric acid stripper, which will remove anodized coatings without attacking the aluminum substrate.

But if you insist on doing it yourself, I am told that anodized coatings can be stripped with Easy Off oven cleaner [on eBay or Amazon], and I know they can be stripped with caustic soda [affil links] (Draino). But not only are these materials dangerous to work with (one drop in your eye can blind you), they don't stop when the anodized coating is gone, they attack the aluminum--so it's not as good as the chromic-phosphoric stripper which attacks only the anodized coating and not bare aluminum. Good luck.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2001

5% caustic (sodium hydroxide) and 95% H2O (water) in a bath heated no less than 140 degrees for 3 minutes. Cooler temps require more minutes. I think you can buy this stuff at Lowes.

William Nelson
- Jemison, Alabama USA
2006