Corrosion protection

[R Rinker]

I'm building a Zenith 750 Super Duty kit. I'm an A&P as well as having owned Cessna's and have seen the progression of corrosion on aluminum as well as other aircraft part over the years. This one may also go on floats. The factory recommends and uses Cortex, which is basically a soft rubber barrier prevention. I've seen Alodined and Zinc Chromated parts that have survived many years in good shape. I have a tendency to suspect that for the tail & wings especially, zinc chromate would be better than the cortex for the long run. I'm running into a lot of confusion as to all of this. Can I apply zinc chromate on bare aluminum?....or do I need some prep cleaner (other than plain water), or etching prep or...??? Is there more advanced products that are easy & simple to apply that are as effective? I've seen panels that were zinc chromated and 50 years later are still in good shape, but unprotected adjoining panels were degraded. I suspect Zenith recommends Cortex because it is totally safe to use and they don't have to worry about builders learning safety procedures or liability issues.
So, anyone knowledgeable about this please chime in & help out....