Brian Johnson turns steel cable into Damascus steel bars, bending and forging as many as 56 layers for strength and appearance. The steel bars, or "billets", are used for making knife blades. He has also made a steel vise, anvil and a multitude of other tools out of the metal. To reshape the hard steel, he uses heating and forging furnaces that he built himself using a beer keg and a propane tank.

"My single burner forge furnace puts out more than 2,600 degrees F," says Johnson. "The body is a 16-gal., stainless steel beer keg with castable refractory interior."

Making the flux-proof forging furnace was a more complex job. The easy part was cutting a hole for the fire chamber. The refractory cement had to be poured all at once.

"I cut one end off the beer keg and centered a cylinder for the fire chamber inside the keg," recalls Johnson. "Insulation anchors had to be welded  inside the shell to anchor the refractory material should it crack. I bought  some anchors and made more, placing them every 6 in. on center. They give  the refractory mud something to hold to while it cures." Refractory material also had to be formed for the furnace mouth. An earlier  furnace had a steel mouth, but it oxidized with heating and cooling. With  this furnace, he made an outside form for the door and mouth with an inside  square tube. Once the refractory cement was poured and cured, the form and  the inside tube were cut away, and Johnson had a furnace with no interior  steel to oxidize.

Johnson reattached the keg end, first fabricating 1/2-in. grooved rings in each edge. Using 3/8-in. thick, 1-in. bar stock, he made a steel ring to fit inside the two grooves for a tongue and grooved effect.

"I split the ring so it can expand and contract as the forge heats," he says. The forge sits on a 10-ga. steel cone with a shelf and door. The cone serves as both a base and storage for fluxes and other materials. Heavy-duty caster wheels provide mobility. Each wheel is mounted on a He also fabricated a Venturi tube to feed the burner. He describes the Venturi as a tube within a tube that he slides back and forth to achieve the right mix of oxygen and fuel to the burner. Because he runs the propane at tank pressure, the flow of fuel pulls the air into the burner.

"I like a slightly fuel-rich flame," he explains. "If you have an oxygen-rich  flame, you have more problems with oxidation." Johnson mounted a small electric fan at the end of the mouth. It blows a  curtain of air across the handle of pieces being forged, keeping them cooler  and easier to work with. It also disperses heat coming out of the forge,  making it more comfortable to work around.

"The furnaces make it easy to work with metal, which I enjoy," says Johnson. "I make tools and Damascus knife billets, but not the knives. I let others do that."