I was recently chainsaw cleaning up some knuckly pieces and now have a good stock of wood pucks. I have just put on a nice 6"d x 11"diam Beech puck. Hot bed of coals required and 1/2 draft on insert. Good heat pouring out. A few times , just about an hour or so in, I prop up one side with a smaller Ash split to keep the heat up. Anybody else burn "pucks".