As a layman, self-taught panel-basher and sprayer, I always thought I had investigated the technology thoroughly.
To me, a primer, is just that! it primes (prepares) the surface for further treatment.
seems I'm wrong!...
I usually prepare aluminium panels with a Scotchbrite pad (like the green domestic pot-scourers) wipe off with Acetone based thinner until the paper towel has no black streaks, then coat with 2-pack, high-build etch-primer.....this is activated with a Phosphoric acid -containing compound.
Always good results, the phosphating kills the surface corrosion even on pitted panels.
I use 2-pack, isocyanate colour coats....It sets like epoxy cement. high build high durability , low solvent content, so low shrinkage (but you must wear a respirator! )
So, after mechanically cleaning the surface, what do you recommend to passivate and prepare the surface? i appreciate adhesives and paint are different, but as you said, the bond has to be there!