are alternating layers of high-carbon and high-nickel steel. He uses an arc welder to attach a steel handle to the rectangle. This also immobilizes the wafers, allowing Duncan to control them during the forging process. Then, like a baker stuffing a loaf of bread dough into an oven, Duncan places the billet into the forge. We pour ourselves a cup of coffee and wait. Within minutes, the billet reaches welding temperature, which is about 2,300 degrees. This is the temperature at which steel molecules separate into a semi-liquid state, allowing them to bond. At this point, the 10 layers will be hot enough to forge into one solid billet.
Duncan removes the billet from the heated forge and puts it under a hydraulic press, which squeezes the layers of steel into one homogeneous mass. He creases the middle of the billet after pressing the layers together and expanding them to the right length. This allows Duncan to fold the billet in half. Now, instead of 10 layers, the billet contains 20 layers. After reheating, he'll fold it again to form 40 layers, then 80, then 160, on up to however many Duncan desires.
"The more layers you have, the better it is from both a visual perspective and for strength," Duncan said. "But, you want to see the layers when you etch it, so I stop at around 300-400 layers. People like that because it's pleasing to the eye. Personally, I like my billets to have about 300 layers to get the effect I want."
During repeated weldings, it is important to seal out oxygen. For this, Duncan douses the billet with regular laundry borax (without soap) before putting it back in the forge. This process is called "fluxing." It prevents oxidation from occurring between the layers and ruining the billet.
With each fold, Duncan presses the billet flat, squeezing the layers ever tighter. With each stroke of the press, flux squirts out in all directions as far as 15 feet. The scars on Duncan's arms are souvenirs from years of being splattered by molten flux.
"You can avoid that by wearing burn-resistant clothing," Duncan said, "but you feel how hot it is in here now. Imagine how hot it gets in here in July and August. If it's 90 degrees outside, then it's 120 degrees inside the shop. You can hardly stand it. Sure, you get burned sometimes, but