This spring I chipped off loose rust with a screwdriver and a scraper before brushing on Fluid Film. It looked pretty good for a while but yesterday I noticed some peeling rust on the fender and looked a little closer. 

Come to find out, the deep-creep nature of fluid film actually loosens the rust flakes and paint with corrosion under it! I ended up re-scraping everything I did just 3 months ago. It actually looks way better now. The frame is smooth and there was even little spots of bare, gray metal poking through. So apparently fluid film is also a rust remover? Haha

To help out the next guy, I also wanted to mention that the best way I've found to get the loosened scale off is a combination of flathead screwdriver and a 2 cent air gun with a tiny metal nozzle and 120 psi. The air easily gets under the loose stuff and pops it off like a paint scraper with the added benefit of getting into tiny crevices, voids, and cup-shaped things like the lower trough of the frame rail, the rear axle shackles, and the hollow cross members. 

Trigger warning: the rusty frame in the photos is \*after\* both rounds of cleaning and before the second coat of fluid film. It looks bad in the photos but hopefully the metal that's left will stick around a while now the rust is gone and it'll be kept greased up

Fluid film in the rust belt