Here’s a discussion of dyed chromate conversion coatings.
Thanks for the info!
I didn’t see in that article where it mentioned adversely affecting electrical conductivity but I found some other related articles that do speak to the various dyes, especially the darker ones, contributing to the thickness and therefore reducing electrical properties. The conversion coating isn’t the issue, it’s dyes that may be added afterward to change the color. Not much different than top coating after conversion except the dye is being adsorbed into the chromate. I particularly liked they used the correct term there 
Thanks for the help!
We found that heavy, undyed chromate conversion coatings had less electrical conductivity than desired. Our QA folks checked for that. GSFC is (well, was) very conservative. I’m not sure now because of the mass “executions” that took place at the center. They were always known as the most conservative NASA center.
I used Alodine a lot when I was in the Navy. Anytime an aluminum surface was taken down to bare metal, it had to be alodined before it was painted. Never heard it called “Alodized”. When I was in an A-7 (aka SLUF) squadron, I Alodined a lot of radar frames which were made from magnesium. Magnesium corrodes much faster than aluminum in a salt water environment, and because it served as a ground plane, it could not be painted. Never heard of any conductivity problems with it. On the rest of the aircraft, we would use a zinc-chromate primer before the final coat of paint.
When I transitioned to F-14 Tomcats, Zinc Chromate was banned so it was just Alodine and paint. We didn’t have any magnesium in the radar, or anywhere else in the aircraft as far as I know.
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