Anodizing Question

[N1ESE]

Does anyone know if the anodizing process reduces the conductivity of aluminum? I'm wondering if an aluminum chassis would still make for a good ground point if it is anodized.

Thanks

- JT

[Aengus]

Anodised portion is an insulator. If you want to use an anodised chassis as ground, you have to scrape away the anodisation at the connection point. Typically, one uses a bolt with a star (lock) washer to dig into the chassis as well.

Regards.

Aengus

[N1ESE]

Originally posted by Aengus
Anodised portion is an insulator.

That's what I thought and wanted to confirm. Thanks mate.

- JT

[Stuart Easson]

IIUC exposed aluminum will oxidise and eventually render itself partially or completely non-conductive. The anodisation process simply makes the layer of non-conductive material much thicker and pretty.

Thus I think the step of using the star washers is actually needed even on what look like 'shiny' surfaces, if a good connection is to be maintained.

Stuart

[N1ESE]

Originally posted by Stuart Easson
Thus I think the step of using the star washers is actually needed even on what look like 'shiny' surfaces, if a good connection is to be maintained.

Yup, star washers are a given on all ground source materials. I just needed clarification on how much of an insulator the anodizing process creates.

[sam9]

Allodyne (sp?) is conductive and often used instead of annodizing just for that reason.