How are antique bronzes made?

Wax loss method. (1) Master Mold Making: To make a good bronze ware, there must be a perfect master mold, which is the most critical step in bronze ware making. If it is a copy, it is necessary to use the professional rust removal method of bronze ware to clean the ancient artifacts before copying the mold; If it is an imitation, it is necessary to carve the same master mold as the original antique. The manufacturing method of the master mold is: according to the picture or the original antiquities, mold paraffin or treated gypsum is used to mold the shape similar to the ancient artifacts, and whether the shape of the ancient artifacts is accurate or not can be modified when carving patterns. When sculpting according to pictures, it is impossible to determine the specific position and size of the original patterns, so we take the symmetrical midline of ancient artifacts as the starting point, and calculate the positions and sizes of coarse flowers and back patterns according to the size of ancient artifacts and the size of photos. Then engrave a pattern on the molded shape. When there are differences, adjust the molded shape until the patterns are evenly distributed on the surface of the shape. When carving a pattern, the base of the pattern should be flat, the lines should be smooth, and the carving depth of the pattern must be consistent with the original antiquities. According to this method, if the patterns on the ancient artifacts can be evenly engraved on the molded artifacts, the production of the master mold will be basically completed. Problems in the process of making master mold: burr and circular pattern are easy to appear when mold wax is used as material. In ancient times, patterns were carved on mud lines, and the surface of male lines was flat and square.

(2) Moulding: Previous moulds were all made of gypsum. Because gypsum is fragile and loose after solidification, the three-dimensional sense of the pattern of the mould is not strong, the lines are not smooth enough and the utilization rate is not high. After completion, decorative patterns often deform and lose the charm of the original antiquities. Nowadays, molds are generally made of vulcanized silicone rubber in greenhouses, which is not only simple, but also very effective. In particular, the mold copied on the original antiquities can copy the shape, pattern and charm of the original antiquities without distortion. The disadvantage of this method is that the overall shape is slightly smaller than the original antiquities, but the proportion is very small. If it is not compared with the original antiquities, it is difficult for the naked eye to distinguish the feeling of shrinkage.

(3) Mould shell manufacturing and casting polishing: Now EPC is generally adopted. This method is simple and quick, and can cast bronzes with particularly complicated technology without losing the charm of the original shape. Disadvantages: uneven sidewall thickness. When casting the lost wax shell with silicone rubber mold, it must be trimmed inside and outside. Appearance, the surface of wax shell should be smooth without deformation; Internal correction should be uniform in thickness, angular, smooth and flat. Manufacturing specification for bottom gauge wire and gasket. Casting adopts precision casting method, which is not detailed here. Casting objects should be finely ground and polished. When polishing, we must protect the original shape and pattern of the copper tire, and try our best to make the pattern clear, natural, exquisite and smooth. Finally, the copper tire is old.