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Stripping Hard Coat Anodize

2005

What is the best way to strip hard coat anodized parts? Pitting and base metal etch is not an issue. Solution must be able to operate out of a stainless steel tank.

Bill Griffin
- Waterbury, Connecticut

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2005

Bill,

Try straight Caustic Soda [affil link] and heat it up to 160-180 °F - same as hot caustic etch. Otherwise might try chromic / sulfuric mix found in most trade references, however, this likely to attack stainless. While chromic / sulfuric is more gentle on the basis aluminum once the anodic layer is stripped, the hot caustic etch can't discern the difference between aluminum and aluminum oxide - it's not likely to pit but will remove appreciable aluminum!

Milt Stevenson, Jr.
Anoplate Corporation

Syracuse, New York

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2005

We have had good success, without base material problems, using a solution makeup of 20 g/l chromic acid and 85% phosphoric acid at 3.5% by volume operated at 212 degrees F.

Tim Martin
plating shop - Springfield, Massachusetts