Never adjust the fire with the stack baffle, and I do mean never. The only reason the stack has a baffle on it is to keep rain and critters out of your smoker. The stack needs to be ran WFO always, or you see what will happen, your smoker will start to creosote over, which is a bad thing . Take a plastic pot scrubby and some soapy water and scrub all of that crap out of the whole smoker and inside the stack if you can fit your hand in it.
Then rinse well with the hose, once it's dry start a small fire and let it dry 100%. While it's drying, spray a little vegetable oil on anything that will rust to season it, like you do with cast iron pans. Keep the fire going for at least an hour so the oil carbonizes and forms a layer of protection over the steel.
From now on, never use the stack during a smoke always WFO, you control the heat by adding more fuel and more air to the fuel by adjusting the damper or dampers on the firebox only.
Good luck and have fun.
Dan
