Metalworking in Bronze Age China: The Lost-Wax Process By Peng Pe ...

appendages of the Zeng pan either were left by the liquid wax as it cooled¹⁴ or, more likely, were formed from a series of small, staggered wax slices set in a laminated manner, whose purpose remains unclear (fig. 71). The irregular shapes and wrinkled surfaces of some of the rods within the rim appendage of the zun were also likely a byproduct of handwork on the wax model.¹⁵ It is notable that many rods in the famous jin (altar table) from the mid-sixth century BCE tomb Xiasi M2 in Xichuan County, Henan Province (fig. 26), another probable lost-wax casting, lack consistent thickness (see figs. 33, 34b), probably because the melting components of the wax model were pressed and fused together.¹⁶ In the method proposed by Perspective 2, such rods would have been produced in a tunnel-drilling manner, which cannot explain the inconsistent thickness of the rods. Moreover, an abundance of handmade marks, including rubbing and pinching imprints, are present on these same types of rods in the jin table, making the validity of Perspective 2 still more unlikely.

The lost-wax casting method requires the use of a usually complex gate/venting system (fig. 25) composed of pouring and venting channels that were originally made of wax and attached to the model.¹⁷ Once the casting was complete, these channels took the form of bronze rods that had to be removed from the finished vessel except when they were concealed inside it. In comparison to the section-mold process, the lost-wax process allows for easier construction of a greater number of runners and vents, which were needed to prevent the formation of air pockets in the casting of complex shapes.¹⁸ A number of the bronze stumps that are evenly distributed on the back of the rim appendage of the zun are likely the remains of such a venting system, removed after casting. Some of the mistakenly identified “runners” for the “individually precast” pattern elements asserted by Perspective 1 (fig. 18) are probably simply the scars created during the removal of the bronze strips (the original “vents”) from the pattern elements on the finished piece. The Xichuan jin contained a similar irregularly shaped inner structure with many bronze rods in mild disarray, an obvious feature of the lost-wax venting system¹⁹ (fig.