Here is the situation: Building a propane smoker. Interior is metal (34" x 28" x 70"). Solid box. Only way for heat and smoke to escape is thru 3 dampers (one on each side and top). Frame and exterior is wood. Reclaimed pallet wood. A lot of gaps, nail holes, etc. Insulation between wood and metal. Smoker is located outdoors. Questions: 1) Does the exterior need to be sealed? 2) If yes, what works best? Any help/suggestions are appreciated. Thank you, Folks. Otownhaji.