Surface rust repair advice - floor boards, headliner, rear cab

[Airborne Janitor]

Pulled the carpet/interior on my 89 MJ and was pleasantly surprised to find nothing but surface rust. Floorboards passed the "screwdriver puncture test" with flying colors.

 

 

I plan to wire wheel, vacuum, soap & water, then POR-15 to treat the floors.

The headliner area is a little different issue:

 

 

The roof is little more rusty than the floorboard, but I plan to do the same treatment: wire wheel, vacuum, soap & water, then POR-15.

The big issue is the area behind the roof where it meets the back of the cab (outlined in red). There is severe surface rust inside the channel that is impossible to get to:

 

 

What are the recommendations for treating this area? Would also appreciate any additional advice/tips in regards to prep/repair of surface rust. Thanks.

[Dzimm]

The only thing I can think of is use a piece of sandpaper and a plastic scraper and use the scraper to push around the sandpaper back in there but even that won't do a great job. There really is no good way to get into areas like that other than media blasting and doing that inside the cab would be a freaking mess.

[mark 39]

        Eastwood has a rust encapsulating spray with a flexible tube that fits on the nozzle. It's designed for use in blind spaces. I use Fluid Film spray in frame channels, rocker boxes, lower door panels, etc. myself. It's a lanolin oil base, doesn't dry out, has a not totally unpleasant odor for a week or two. Google "auto rust prevention", you"ll find more info than you'll want to read on fixing your problem.

[DirtyComanche]

I'd try the Eastwood product personally: http://www.eastwood.com/internal-frame-coating-w-spray-nozzle-qt.html

 

You may want to drill a few more small holes in the channel to help get in there better.

 

Everything else would be an insane PITA to do, and short of actually drilling the welds out a removing the piece I doubt you would get any better of results.