Hahaha yeah the blowing up part. I had a bunch of seasoned brick from the fireplace I dismantled in the old house, I used that for the liner and concrete block with a layer of fire brick on top for the base, dug about 2 feet down into the ground. I then faced/stuccoed the brick liner with high heat mortar (7000degree rating) and heated that up with a blow drier to adhere it to the walls. The bluestone top is pushed back enough not to take direct heat. I'm looking for a square metal insert that's affordable to drop in but for now I've had over a dozen burns and it seems to be holding fine. I've got no problem rebuilding it in a few years if it begins to fall apart but I'm not too worried about it exploding on me. All in all I'm into it for about $125 bucks.