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West Mexican smiths worked primarily in copper during the initial period, with some low-arsenic alloys, as well as occasional employment of silver and gold. Lost-wax cast bells were introduced from lower Central America and Colombia during this phase, along with several classes of cold-worked ornaments and hand tools, such as needles and tweezers.
These are mostly gold or a gold alloy (with copper or silver) and have been found to be largely cold hammered and sand-polished alluvial nuggets, although a few items seem to have been produced by lost wax casting. It is presumed that at least some of these items were acquired by trade from Colombia. [39]
A wax pattern used to create a jet engine turbine blade. Castings can be made from an original wax model (the direct method) or from wax replicas of an original pattern that need not be made from wax (the indirect method). The following steps describe the indirect process, which can take two to seven days to complete.
A wax model is obtained either from injection into a rubber mould or by being custom-made by carving. The wax or waxes are sprued and fused onto a rubber base, called a "sprue base". Then a metal flask, which resembles a short length of steel pipe that ranges roughly from 3.5 to 15 centimeters tall and wide, is put over the sprue base and the ...
10th century BC – Glass production begins in ancient Near East; 1st millennium BC – Pewter beginning to be used in China and Egypt; 1000 BC – The Phoenicians introduce dyes made from the purple murex. [1] 3rd century BC – Wootz steel, the first crucible steel, is invented in ancient India; 50s BC – Glassblowing techniques flourish in ...
A very important advance in glass manufacture was the technique of adding lead oxide to the molten glass; this improved the appearance of the glass and made it easier to melt using sea-coal as a furnace fuel. This technique also increased the "working period" of the glass, making it easier to manipulate.
Window glass was formed by casting into flat clay molds then removed and cleaned. [12] The texture in stained glass comes from the texture the sand mold left on the side in contact with the mold. [12] Polymeric composites also made an appearance during this time frame in the form of wood.
Tumbaga objects were often made using a combination of the lost wax technique and depletion gilding. An alloy of varying proportions of copper, silver, and gold (typically in a percentage ratio of 80:15:5) was cast. It was burned after removal, turning surface copper into copper oxide, which was mechanically removed.