I believe we use DuPont Variprime for our aluminum priming rather than a PPG product. It is indeed a self-etching, HERE is a link to more info. This primer is used fairly widely by kit builders coincidentally who are seeking improved corrosion resistance.
Though it is not on the price sheet, we can prime all the aluminum pieces for a new aircraft where it might be used around salt water for example. That option is $8,000 and we don't have a precise number on how much weight it adds. No one has asked, but we could probably do this for a kit as well, the price would be the same. For reasons Mitch indicates above it really isn't necessary for a land-based plane, or even one with floats used on fresh water during the summer but kept inside during the winter.
Randy Lervold
Thanks for the replies.
I guess I want the best of both worlds. No weight gain and corrosion proofing. That's why I was trying to understand if just straight alodining would be worthwhile. This would also result in no dimensional changes to the parts and maintain electrical bonding.
The aluminum will need to be etched so water lays flat on the metal. Then treat with alodine. I've also heard that a followup etching will restore more surface conductivity. It won't be a sea plane and will be based in an arid environment so really none of this is necessary. But if there is no weight gain and it's only labor and material, then it's a consideration. Anyway still trying to figure out what to do.
I'm still a couple yrs out from starting a CC kit build so I've got some time to sort it out.