Probably a dumb question, but I want to be sure not to put any spots on my practically cherry Jotul 118 (the old green enameled one). The top is not meant for cooking and does have the green enameled finish on it, but I'm assuming it is just fine to place an iron kettle on it to generate some humidity. I won't see any change in color or anything beyond scratching (if I'm not careful) right?!