Dont do this, at least i wouldnt suggest using acid based rust removers.
Say goodbye to your bases and sidewalls if you do.....
Vinegar(or baking soda and water til its pasty) and a wire brush carefully,
followed by industrial steel wool(can find it right next to sandpaper in EVERY tool store)
If this combo doesnt take care of it or if its still has black spots that means the rust has pitted itself into the metal and is to deep to be removed with hand abrasives and will keep reoccuring
If the metals pitted or rust keeps reoccuring frequently a fresh edge tune and keeping them dry from there on out will do the trick.
I also cover my edges in wax in the offseason, like glob it on, its super humid in the summer where i live....