It is almost impossiable to kill a cast iron pan. A well seasoned pan that has been put away wet and then out of service for a while can get a little surface rust. Often this rust can be easily removed with a little cooking oil (olive, peanut, vetgetable, whatever is handy) and a paper napkin just wipe it out rinse in water (no soap) and rewipe with oil again and you are good to go. If this didnt work to your satisfaction then use the cooking oil and some steel wool, scour until satisfied. Wash the pan with a small amount of liquid soap, rinse thoughly, wipe dry, coat oil all surfaces inside and out with cooking oil, put into an oven at 300 for an hour or so to reseason. Helpful maintainance hint: After cooking with cast iron just rinse and wipe out the pan do not use soap as it ruins the taste of subsequent meals and also attacks the non stick seasoned surface. To sterilze the pan after cleaning put in 150+ oven or stove top at medium for 10 to 15 min. If you think that you might not use pan for a while then lightly coat the pan with cooking oil before putting it away.