I just got a Weber Smokey Mountain 18. Got it used. Cleaned it up, replaced some screws and such because they were rusted badly. Rust also built up on the side bars and anything non black porcelain on the inside. A few screw were so rusted they could not be removed. Cleaned it all up and smoked on it yesterday. However I am getting the rust build up again on everything, new screws bolts, the water pan, the side metal bars, etc. Anyone have this happen and have a solution? Thank you for responses in advance!