text: metal rusts the most where?and rusts the least where.? im kinda wondering...like cause metal stuff in my house is rusting everywhere and i like to know more about it...i mean im pwetty stupid on that.and if you can,please give websites on it metal only needs one thing to rust, oxygen.  water and salt are catalyst, but really it's metal oxidizing.  paint helps prevent rust because it keeps oxygen from making contact with metal.  so metal will rust more when there is a lot of heat and oxygen (heat speeds the oxidization).