Coppersmith extensive degree it must be annealed. This process involves heating the metal and then rapidly cooling it in water. The cooling stage is known as quenching. By heating the copper, the molecules in the metal are relaxed, and thus able to align themselves in a more uniform fashion. This allows for easier shaping of the metal. In order to keep this uniformity within the metal, it is cooled instantly. This prevents the molecules from moving around and causing tension in the structure of the metal. Unlike ferrous metals—which must be cooled slowly to anneal—copper can be cooled slowly in air
Glass-to-metal seal glass, it is an advantage to get a thin bright red containing layer between copper and glass. This is done by borating. After W.J. Scott a copper plated tungsten wire is immersed for about 30 s in chromic acid and then washed thoroughly in running tap water. Then it is dipped into a saturated solution of borax and heated to bright red heat in the oxidizing part of a gas flame. Possibly followed by quenching in water and drying. Another method is to oxidize the copper slightly in a gas flame and then to dip it into borax solution and