Yesterday I decided to test my new 14.5" WSM by doing a test cook. I loaded the charcoal bin and used the Minion method for the burn. I covered the outside of the water bowl with heavy duty foil and filled it with hot water. I left the racks out as I wasn't actually cooking anything. Placed the lid on the top and away we go. I kept the temp within the smoking range on the lid thermometer. The "cook" lasted about five hours. When I was finished, there was still water left in the pan which was ok. My odd result is that the inside of the main portion of the smoker as well as the inside of the lid are now covered with a rust colored crud. I'm wondering what I did wrong. I have pictures, but it appears I can't attach them to this post.