Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Although I didnt understand a word Raphael, I believe you were lightly cursing in French  , I usually try very hard to not leave water residue in the boiler, in my shop I have an overhead furnace that blows down on my radial arm saw, this serves as my "paint drying/curing spot" & my "boiler drying out spot." it may be foolish on my part, but with boilers that are flame fired I have been known to apply a little heat for 30 seconds or so to dry up the few drops left over after I've thoroughly run compressed air threw the entire system.
I'm sorry you had problems with a boiler stored away with water in it.