The metal thickness isn't all that thick, but what's between the metal sheets is 2" on most of the BWS models. That 2" of high temp insulation is effecient all year and heaven when you're smokin in the winter.
The outide sheet is powdercoated for protection against the weather elements and sheet inside the firebox is far enough away from the actual fire to stay in good shape. The inside sheet inside the smoke chamber only requires some seasoning from time to time to keep it protected.
If you don't put it away wet, it should provide many years of enjoyment
Backwoods Gator (former smoker)
Backwoods Party (former smoker)