Disassemble the smoker by removing any parts attached by screws or bolts, which will allow you to easily reach all the areas where rust may be accumulating. Inspect the smoker completely and determine all the places where rust needs to be removed. Rust may be in hidden areas inside lids or in other areas that are not immediately obvious.
Brush all rusted areas with a wire brush to remove loose bits of rust and other debris. Use a circular motion to work out as much loose material as possible. You can rinse the brush with water to clean it out and continue using the brush on other areas. If there is a large amount of rust on the smoker, you should rinse regularly to keep the brush clean.
Attach 120-grit sandpaper to an orbital sander. Put on a protective mask to prevent breathing in rust particles. Plug the device in, if necessary, and press it against the rusty area of the smoker. Use the orbital sander to remove the rust from the smoker completely or at least take the surface down as thin as possible. Move the sander in circles and avoid keeping the sander in the same place or it will wear down the surface too much. Keep working in circles until the rust has been removed.
Fill a bucket with soapy hot water and use a sponge or scouring pad to wash down the entire smoker. This cleaning will wash away the remaining loose material left by the sander and remove any remaining dirt or smoke still stuck to the rest of the smoker. After washing is done, let the smoker dry completely.
Use heat-resistant spray paint, usually found in black, and spray each part of the smoker to give it a clean, new look. Black paint will hide the stains left by the smoke and keep it looking fresh in the backyard despite even the heaviest use.
Reassemble the smoker by replacing all the removed parts and inserting all removed bolts or screws back into their proper positions.