Letter 11002

Alodine electrical conductivity issue 

I understand that Alodine is electrically conducted coating, which does not affect grounding. Is it true?

Lev J. Balanovsky
- Feasterville, PA, USA

Yes, a thin coat to Mil-C-5541class 3 is often used in grounding areas. See AMS-C-5541 [link is to spec at TechStreet] and there are some numbers for this.

Martin Trigg
surface treatment shop - Stroud, Glos, England

Calling the chromate conversions "electrically conductive" is really a misnomer. The Class 3 coatings are so thin that when put under pressure, they short through and those shorts conduct, the coating is not in itself conductive.

The variables involved are both the thickness of the coating, and the surface finish of both mating surfaces. If you had a highly polished pair of surfaces, it would be difficult at best to cause the neseccary "punctures" through the surface thus allowing electrical conductivity. Conversely, extremely rough finishes would allow conductivity with very little pressure.

Bob Denney
- Tampa, FL

Hello,

I am trying to find value (number) for relative conductivity of alodined aluminum.

Andrey Gleener
- Port Moody, BC, Canada

I want to post a question on a different subject.

 

I want to answer or follow-up on this question publicly (in non-commercial fashion).

 

I am a supporting advertiser and want to reach the inquirer privately.