A DIY Metal Furnace

Dig a pit approximately 16 inches deep and 12 inches across. Dig a trench starting 26 inches away from the pit, sloping downward as it approaches it. This trench should connect with the pit about 4 inches up from the bottom.

Set cement blocks around the rim of the pit, in a square. Face the solid sides toward the pit. The pit and block wall will function as the base of the metal casting furnace. The charcoal will go in here, to a depth thick enough to make a very hot fire.

Lay the pipe in the trench so that a fraction of an inch sticks into the pit. Bury the pipe in soil. Insert the nozzle of the bellows into the end that is sticking out of the ground.

Break apart the pieces of charcoal until none of them are bigger than 1 inch across. Use real wood charcoal, and not BBQ briquettes. Keep the charcoal dust remaining from the grinding, which is referred to as the fines. Put the fines into the bottom of the pit. Fill the rest of the base on top of the fines with pieces of charcoal.

Cut out a notch in the base of the flue that is 3 inches tall and 6 inches wide. Use a little drill bit to create a line of holes that outline the notch, and then knock it out the inside piece using the hammer.

Tear the cellulose apart and set it in the wheelbarrow or tub. Mix the clay up with the insulation until they are completely blended together. After the shredded cellulose is entirely coated with clay, wet it and mix it with the other ingredients until it all has the texture of cold pudding.

Cover the entire flue using the clay and cellulose mix. Once it has been coated to a thickness of approximately 1 inch, tightly wrap the chicken wire around it to keep it in its place. Twist the ends of the chicken wire together to keep it from coming off the flue. Place the flue on top of the bed of charcoal.