How much prep for mild frame rust?

[TRevs]

I dropped the fuel tank yesterday because I was smelling gas fumes back there. Getting that all fixed up but while the tank is out I want to treat the mild rust before it gets worse.

(My skid plate is starting to rust through, so it’s being replaced

My question is, how clean does the metal need to be before coating with something like Rust Reformer? I can’t get a wire brush or sandpaper into all the nooks and crannies, and even if I could, it would be incredibly time-consuming. Mainly its that crossmember in front of the tank that needs attention.

 

[TRevs]

 

[ytradio]

If frame is still solid, that is a good strike with a hammer does no real damage, I would pressure wash away the mud dirt and grease let dry and the use Eastwood rust converter. All of the rust does not need to be removed. In fact they recommend that it not be. You can also use the rust encapsulator over it all. These products come in quarts and gallons and spray cans. It can be sprayed or brushed.