The real stuff is a sandwich of thin copper with silver solder on both sides, this is how the manufacturers do it, when I worked for Kaiser steel, they made up brazed carbide tools with 1" shanks for facing and beveling the line pipe that they manufactured, the shanks were machined with a step, all the parts were degreased with trichloroethylene swabbed with flux and heated from the bottom with a torch with a pressure bar holding the carbide blank down, when the silver solidified they were put in a insulated box to cool. After I left, they got an induction heating setup, which was a much better way of doing the heating.