Fillform corrosion on new tank skin

I peeled back the blue plastic from a tank skin the other day and noticed some corriosion in the new skin migrating in from the aft edge of the skin about .25 inches. I have only had the kit for about 6 months and it has been stored in dry conditions (although humidity does get high in the winter when the wet car is parked in the garage here in Seattle).

What is the best approach for removing and stopping this. It is on the outside so I would rather prime it when painting the entire plane. Is it best to leave it alone for now or to adrade it off and Alodine it.

This is also making me reconsider where I store the completed parts until final assembly

I had the same problem with skins last year including the tank skins. All I could do was sand as best I could and use the alodine pen and a little primer. I have no idea if that will do much.