Like other metal jewelry, guitar string pieces can also rust because of various factors. But, one sure way to prevent guitar strings from rusting is to store them properly. It s best to keep them in a cool and dry place. You can also prevent rusting by washing your hands before you wear your jewelry. Also, make sure not to apply lotions or perfumes while wearing your pieces. These items can contribute to the damages, so it is best to avoid them. It is also an excellent idea to clean the guitar string pieces regularly. Doing so will help you remove the oils and sweat from the item that can make it rusty.