Some one started rubbing the car years ago before I bought it. The high areas were exposed down to bare metal after rubbing and unfortunately left untreated. So over the years, surface rust developed. See the picture below
If I am treating a whole panel, I would strip it back as much as I can with wire wheels, flapper disks, etc then use something like De-Oxit then wash it down with water then wash it down with metholated spirit before etch priming. Can I follow the same process if I am only treating few spots (I mean not the whole panel)? What would De-Oxit do to the adjacent areas with paint and undercoat still on?
Raf

You should not get De-Ox on any other painted areas. Ideally you should strip the whole body back to bare metal at the same time. Soda blasting will remove everything but rust.

Check out Rust Bullet from PPS ...I am using this on my car ..the beautiful thing is you can paint over it ...that is the base automotive coating ...great results will follow!

Sorry PPC - Pacific Protective Coatings.... not cheap but good stuff never is!!

Have you heard of soda blasting??? I got a little info and it appears to be the goods ... non acidic and brings metal up to a like new finish ....... maybe worth a look???

I have been using Gibbs Brand Penetrating oil as rust stopper. Works great, gets into the metal pores, such a fine molecular structure, it gets between the metal cells(?).

Have a bare metal job siting for 2 months....ZERO surface rust.

Having said that, it would be perfect for those little patches, but for the right body job, media blast and protect with Gibbs. Without going that far, I would get the wire wheel and 3M disc to get the crap off, then protect with Gibbs.