Hey all - glad to be part of the group! I snagged a free 'under the counter' fridge on the side of the road and am looking to make my first smoker. I've got it pretty well gutter, my last concern before installing heat element and vents is if I should re-insulate the inside. Right now, it's just a metal box with a door. I'm worried it won' hold heat well. Any suggestions on what to put back inside for insulation?