The material started to have spots that look like rust and I’m not able to keep it clean. I have a black round charcoal that my sister gave me has an anniversary gift and it still looks great after 6+ years. Im concern about this “new one” since for no reason it’s getting this small rust like spots on it. I like to take care of my grills. Any chemical you recommend to see if it take care of it. Don’t want to use something that could be to strong that could cause more damage. I do have a cover and use it.