The Casting Process of Yongle Great Bell

The Ming Yongle bell was cast by the clay modeling method (one of the three traditional casting techniques in China - the clay modeling method, the iron modeling method and the lost wax method). First dug a large pit on the ground, with grass and wood and soil to do a good job of the inner wall, painted on top of the fine mud, write a good scripture of the rice paper pasted back on the fine mud, engraved yin character, heating and firing into pottery, and then a circle to do a good job of the outer model. Casting, dozens of furnaces at the same time, the furnace fire, the flame rushes to the sky, the gold splash, copper juice gushing, metal liquid along the mud made of grooves injected into the ceramic model, a casting.

After repeated studies and testimonies, scientists have been able to clearly describe the method and process of casting the Great Bell. This is the first two thousand years ago in the Shangzhou era of the Tao Fan method. To the Ming Dynasty skilled craftsmen have long been in the hands of skilled, pure craftsmanship. They created a spectacular and grand scene: in the ground dug out ten meters square deep hole, first according to the design of the bell model, seven sections of the production for casting the use of the outside of the model, low-temperature drying, baking into pottery. And then according to the bell body radius and thickness of different sections of the design car scraper mold, make the bell of the inner model. When the seven ceramic outer ring in turn butt as the shape of a seven-stage Fudu, the bell of the outer model of the integration of the success of the assembly.

This is a seamless operation, the slightest gap, minute difference will cause "running fire", incurring total failure. In order to withstand the pressure of casting and ensure sufficient strength, the outer model around the undoubtedly filled with soil and layers of tamping. Four imperceptible scars on the side of the knob give away the exact location of the four casting ports. We saw the most typical rain shower casting method: dozens of furnaces lined up along the four channels, the furnace fire flowing gold, copper juice boiling; pit inside and outside the mold at the same time high-temperature preheating. When full of furnace dendrobium gold soup phase rate run out, the ten thousand bell will be completed in one fell swoop. Looking back at this scene, five hundred years ago, the handmade workshop production, clearly has been through the modern scale of large-scale industry and the atmosphere.

The bell contains other trace metals such as zinc, aluminum, iron, magnesium, gold, silver, etc. Although the number used is very small, but the smelting of these metals and the technical requirements of the technical content is the same, such as the world's leading level of zinc refining in the field here. Add a small amount of zinc, according to the then known copper, zinc ratio can be dissolved together to produce brass principle, it is estimated that in order to add some of the golden luster in order to seek visual effect, and add a small amount of gold, silver is thought to show the preciousness of the Brahma bells.

Cooling is another deadly process. Inside the pit is a mass of unquenched earth and streaming flames, and the rate of cooling must be controlled to prevent the bell from exploding. The world-famous Russian bell cracked due to a lapse in the cooling process and was reduced to a mute bell. The pit where the Yongle Bell was conceived is a natural automatic cooling system. It can be imagined that the laborious craftsmen paid how much care and attention to ensure that the Yongle Great Bell in the safe cooling peacefully born.

The bell cast, to be in winter, first every mile to dig a well, and then along the road to dig ditches to attract water, splash water icing, and then began to carry; bell on the road step by step skating dozens of miles to the palace. Then slide to the ice on the mound, and then build the bell tower, bell hanging on the roof, spring thaw after taking the soil and bell hanging. Bell bracket four arms eight forked, bell button divided into upper and lower two sections, the middle of the piercing nails fixed in the beams, with a wooden pestle gently hit, it will send out the heart-stopping sound of the bell. Yongle bell is cast in the De Shengmen within the casting of the bell factory, cast and stored in the Hanjing factory (site in the production of today's Songzhu Temple area).