I had originally planned to submerge the door in vinegar to rerust it until I calculated that it would require 60 gallons so I opted to spend the money on a sandblaster. It's still cold here and it would have to sit for a very long time for that to work.
The door is too large to submerge in any liquid and the nearest place that dips parts is 200 miles away... I'm sure there are ways to do this. I've seen some of the hulks guys have pulled out of fields.
