Metal finishing Q&As since 1989

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Hard coat electrical insulation values

 

Hi,

I am looking for information on hard coat anodizing. Specifically, I am looking for electrical insulation properties. Can you help me. What is the insulation value (volts/in or similar) for the coating, assuming not on a thread or scratched.

Chris Sperry
- Plymouth, MN, USA

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Pages 715 to 716 of the book The Surface Treatment and Finishing of Aluminum and Its Alloys by S. Wernick, R. Pinner, P.G. Sheasby (vol 2) deals with the subject you might be interested in.

Dado Macapagal
- Toronto, Ontario
 

Hi Chris,

Of course Hardcoat is reputed to be an excellent electric insulator. Now, depending on the kind of the process you're using you'll obtain different breakdown voltages. In fact, there are some processes which produce a hard coat having breakdown voltages as high as 1000 to 1500 volts D.C. on a flat surface with a coating of 2 to 3 mils, and up to 5000 volts D.C. on a flat surface with a coating of 7 to 8 mils. However, a somewhat lower voltage breakdown is always expected at sharp corners or edges.

Wishing a merry Christmas and happy New Year to all of the finishing.com family, I'm hoping this would help.

Hocine Djellab
Verdun Anodizing Inc. - Verdun, Qc, CANADA