Rusty Frame
 

I have a 2005 Hummer H2. The frame looks like crap. It's rusty and the dealership coated it with some undercoating that's peeling https://cimg1.ibsrv.net/gimg/www.hum...1fe9a40cc2.jpg
https://cimg2.ibsrv.net/gimg/www.hum...2474f31089.jpg
off. Does anyone have any suggestions on how to clean the frame up and what to use to coat it? I want something that's going to last awhile!

I had light surface rust, nothing like that but I used an assortment of air die grinders and wire wheels/cups to remove the rust. Then I cleaned those spots with brake cleaner, and covered the bare metal with 2 coats of POR-15. With that must rust you might want to consider sand blasting, going that by hand would take a while.

Got the same problem, not as bad but was curious if dustless blasting would work better than traditional sand blasting. Whatever you decide hopefully you will document the process...

Looks like someone sprayed the frame with undercoat at some time. Undercoat is one of the worst things ever invented. When it delaminates from the metal, it leaves a space for water and dirt to accumulate and over time you get RUST! And it is usually much worse than what you would have found, if the frame were not undercoated ! I agree with the previous post, scrape it all off, grind it down and hit it with an anti rust / etching primer and or Por 15.