Jay Shirey's Firebrick Forge Need a little more space than a single brick forge affords? Jay Shirey built this firebrick forge using 7 soft insulating firebricks. The body of the forge is comprised of 6 firebricks carved as show in the diagram below and the "doors" are composed of a seventh brick split in two. The forced air burner runs off of a standard 20# propane bottle and has an adjustible high pressure regulator, shut-off cock valve and needle valve inline to provide control and operation. For a blower, Jay salvaged a small squirrel cage blower off of an old kerosene heater.