Around a month ago I was experimenting with a new fuel source, nut-coal from tractor supply, and with that in mind. Six of my fire-bricks were completely destroyed,looked like glass, looking back I wish I had taken pictures. Was thinking i wanted to keep using charcoal, but like the coal because of no fire-fleas. Has this happened to anyone other then me, and what can i do to prevent this, or a different lining, any help appreciated