It might happen that your grill(s) get a bit rusty. This is normal and easy to take care off.
To prevent this from happening it is best to season your grills after each use coat your grates with some vegetable oil.
You can also choose to use vinegar and salt to get the rust of your grills. Mix two cups of vinegar and one cup of salt in a bowl, place your grill(s) in a garbage bag and pour the mixture in it. Close the bag and place it flat on the ground. After soaking for a few hours you can wipe off the rust with an old rag.