I cannot comment since I have only owned it for about 30-days now, however, water and metal are not a good combination (you can see naval military ships rust too, with all the care they get and the quality of material used), so, I suggest to always leave the lid open when not in use to let water left in cracks and crevices to evaporate (unless you have a pet which may jump into it, in that case, train your pet not to do it :-))