Matt, I've only ever worked as an electrician on Tornados and now Typhoon but I know a bit about it. Most (if not all aircraft) fuselages are made from aluminium which I guess limits the corrosion to dissimilar metal corrosion between components. The Harrier, Typhoon & most other new aircraft are increasingly made of composite materials so they don't corrode in the traditional sense but we do have problems with cracking & delamination etc. I'm pretty sure they just use an etch primer (pale green in colour) and then top coats.

The aircraft do get washed, NDT'd (non destructive test) & painted periodically and a corrosion control register is maintained so any corrosion would be be noted and dealt with as and when required.

So, the answer to your question is: No, I don't think so.