I have to store my dutch ovens in the garage, as a result I am getting rust on the outsides. The insides are fine and even when I don't use them for a long period of several/many months I don't get rust there as there is good seasoning. I alternate between putting a piece of paper towel over the rim and doing nothing.
My garage is very damp, my tools often get rust on them but I will not put a dehumidifier in it due to the cost. I keep all my Coleman lanterns (about 25) and Coleman stoves (about 8) there and haven't noticed anything but they are painted.
Other than taking them out and re-seasoning the outside and baking with them or putting them on the grill to season over and over does anyone have any ideas?