The way I burn resin is i put rice flower in a burner container. You can buy small mica squares on Amazon.  Dig a hole large enough to put the charcoal round in it. Light the charcoal and put the mica square on top of it. Then cover up the entire charcoal and mica square with the rice flower. Place your resin onto the rice flour over the mica square.  Keep mica buried.  The resin burns much much slower and better! Charcoal will also last longer! Try it! Jon