More info needed from you about what surface you are polishing, but ...No advice, no answers?
If you've ever seen a corroded airframe, you'd know that's not true.Paint is a waste of money, time and weight.
Depends on the plane. I considered polished finish but big square slab sides do not lend themselves to it - they show every crease and ripple. You really need a curvy fuse, like Spacey's Hummelbird or a Ryan ST (or a Lockheed Connie for that matter) to really look nice in polished ally.All really good aircraft have a polished finish. Paint is a waste of money, time and weight.
I agree with wrap where needed. Easy to apply and remove without effecting the skin.