Bronze Sculpture Process Flow

Clay sculpture

Design sculpture modeling, first of all for the sculpture modeling of the overall structure and effect of the full design and make drawings, for the next clay production lay the foundation. The predecessor of each product needs a clay sculpture prototype, clay sculpture is after the sculptor in the original design manuscript on the basis of repeated speculation, after careful re-creation, the shape of clay sculpture, charm of the performance or not, the expression of the intention of a direct impact on the quality of the product in the future, an excellent bronze sculpture can not be separated from the outstanding sculptor. The concrete operation steps of the clay sculpture are: the selection of the material for the sculpture clay, the spraying of water to wake the clay, the building of the skeleton, the supporting device, the large clay on the clay, and the shaping. From this stage, the clay must be sprayed with water to keep it from cracking, and the plastic film must be covered halfway to keep it hydrated until the sculpture is finished, which is done by a professional sculptor. After the completion of large-scale sculpture, to inform the customer to clay modeling audit and put forward comments or modifications. Continue to refine the adjustment and details to achieve perfection, all finished modeling after the use of scraping the overall scraping.

Silicone mold

According to the size and fineness of the mould, different remaking technology is adopted. The sculpture modeling is bigger, the precision request is relatively low uses the gypsum, the glass fiber reinforced plastic to turn the mold; the sculpture modeling is small, the precision request is relatively high uses the silica gel to turn the mold. In general, the use of a combination of two ways to turn the mold. In the same sculpture transition, undulation, grain, detail relatively simple large-area modeling using plaster, FRP flip model, local detail features, complex grain and other modeling using silicone flip model. Turn over Gypsum, FRP mold, in the clay mold with sections of the block mold division design, and then spray release agent as isolation protection. Professional turnover technician ratio of gypsum slurry on the clay plastic cover, until gypsum harden and dry to start mold release, Mold release to fix the Gripper in the block, gripper with plaster and hemp wrapped wooden piles to make. After demoulding, the residual mud on the block mould is removed, and after finishing, the plaster mould is carefully repaired and polished. Glass fiber reinforced plastic die opening method is basically the same. Turn over the silica gel mold, in the clay brush according to the process on the silica gel. The silica gel is mixed with silica gel oil, curing agent and so on. First brush a layer, two with gauze brush together, generally need to brush three to five layers. Require even brush, gauze paste reasonable, prevent deformation. Then, a plaster is attached to the outer part of the silica gel to fix its type. After curing, open mold, finishing.

Wax model of statue

Now the common casting methods of sculpture art casting are“Lost wax method” and“Sand mold casting”. “Lost wax method” is an ancient metal casting method. The mould is made of wax, and the molding material is applied externally to form an integral casting mould. The wax is removed by heating to form a cavity mold, which is poured into a liquid metal and cooled to obtain a molded casting. This method belongs to the“Investment casting” category, generally used to cast very fine, very complex shape of the copper carving class of art. “Sand casting” is a casting method for producing castings in sand molds. Because the molding material used in sand mold casting is cheap and easy to obtain, the mold making is simple, and it can adapt to the single piece production, batch production and mass production. Generally used in large castings, relatively low precision. Now the cast bronze sculpture generally adopts two ways to complete with each other flat.

Sculptures Sand shell

The purpose of hanging the shell is to form a casting cavity outside the wax mold. Generally use silica sol hanging shell. This is a more traditional process. To do a good job of wax film in the silica sol slurry barrel for a certain time, and then with a layer of fine quartz sand to make a good wax shape hanging fine sand covered up. Every time you hang it, hang it dry. Then hang it up again. The sand shell is made 9mm (5-7 layers) thick, and the number of times of hanging sand is related to the size of the sculpture. The bigger ones should be hung ten to twenty times. It takes a long time. Forming a relatively hard casting cavity. The advantage of this technique is that the surface treatment of the artwork is exquisite, not to destroy the sculptor’s brush strokes. Basically maintain the original appearance of the sculpture prototype, the disadvantage is long cycle, high cost. Some businesses have cast the method such as gypsum cavity, short period, but slightly worse surface treatment, easy to appear common casting defects. More simple works such as flat relief, large copper coins, bronze Buddha’s back and other works of light surface without too complex process can be taken“Resin sandbox production.”. After hanging the shell, put into the high-heat 140-160 ° C oven or high-pressure steam pot inside the shell of the wax burned until the formation of hollow cavity. Then the hollow cavity is put into the sintering furnace and sintered at 800 ° C-1000 ° C for use. So the casting cavity is done.

Casting

1. Material Selection: brass, tin bronze and pure copper are the main three kinds of copper used in foundry. Brass is copper containing a certain element of zinc. Generally zinc content in 30-40% of brass is often used to do art casting. Brass has good mechanical properties, good plasticity in hot and cold state, easy cutting, easy brazing and welding, corrosion resistance. Gloss, fineness, rich artistic expression. In addition, the price of brass is relatively cheap, is the most commonly used modern copper carving process of a material. In addition to brass, copper alloy is generally known as bronze. Tin Bronze is one of the oldest alloys in use. In ancient times, our country often used to make tripod, bell, weapon, bronze mirror and so on. The tin bronze has good corrosion resistance, good toughness, easy processing, high hardness, small shrinkage and good durability. It is also a commonly used art casting material.

2. The casting process of the bronze carving is complex, which involves the professional operation knowledge and steps in all aspects. A brief introduction follows. The sintered spare hollow cavity is prepared. Measure copper and some metals such as zinc and tin in proportion, put them into crucible, and heat them to 1100-1500 °C. Until the copper and other metals in the crucible are completely melted and mixed. The copper liquid is then immediately injected into the cavity, cooling the outer sand shell will be broken, stripped out of the copper is the rough embryo of the product. It should be particularly pointed out that due to the pursuit of low-cost, Vicious competition, individual manufacturers often use unqualified raw materials such as impure copper, inferior scrap copper, and so on, coupled with the lack of technical clearance, the process plan is unreasonable, it can cause various casting defects in copper castings.

polishing

All newly cast bronze carvings and bronze carvings need sand cleaning, risers cleaning, polishing and other processes, so that the appearance of the bronze carvings more smooth and delicate, more noble bronze carving phase, this requires a serious and responsible auxiliary workers, rigorous and meticulous process operation.

Coloring

After the bronze carvings are basically finished, we can then proceed with the surface coloring.

Oiling, sealing wax

After coloring is the last step on the oil, sealing wax. After so many steps, a piece of bronze is cast. Oiling and sealing wax will keep our bronze sculptures up to date for a long time.