Wrought copper process
Wrought copper is a process different from cast copper. It is created on a copper plate. The texture of the copper plate becomes soft after heating, and the hardness is restored after hammering. Repeat this process to finally produce wrought copper reliefs and wrought copper Sculptures and other round-carving works of art or other daily and industrial articles. With the improvement of people's living standards and aesthetic appeal, the traditional craft of forging copper is especially popular among designers and the public in the arts and crafts field.
Fire, hammer and chisel are the three important elements of wrought copper.
Small-scale copper wrought work or partial processing of large-scale copper wrought works can be heated by high temperature generated by oxygen and acetylene, while large-scale works need to be heated by blast furnace fire. This part of heating is relatively easy. The heated copper plate should be flattened with a leather hammer.
Appropriate proportion of raw materials such as rosin and soil are melted in a container, and then poured into a workbench with a 3-5 cm high edge around it to fix the heated copper plate. This method is stronger and stronger than the original sandbag method. The hammer chisel feels good.
The use of hammers and chisel is the key to the whole copper forging process, which is why "wrought copper" is also called "hard copper". Every copper forging master has hundreds of chisels of various forms in his hands. Using these chisels to outline the ups and downs on the copper plate is called "wire routing". It will take several years to quickly and accurately wire the wires according to the drawings. Kung fu, especially some key parts, such as the facial features of the characters. Large-scale copper forging works require the cooperation and collective creation of multiple copper forging craftsmen. Some processes require the cooperation of the craftsmen to be very tacit. For example, sometimes it is necessary to hang the copper plate. The staggered lines reach perfection.
After that, the work is welded and assembled, polished and polished, or aged and painted, and a wrought copper work is completed.
Here is a detailed introduction to the production process of the lower forged bronze sculpture:
The first step: making clay drafts
The clay sculpture draft is an important link in the production process of forged bronze sculptures. It is the main step to determine the basic shape and style of the sculpture. It needs to be approved by Party A. After the draft is confirmed, the sculpture clay draft can be enlarged and produced.
Step 2: Turn over the mold
After the clay draft is confirmed by Party A, the mold can be reproduced (usually the glass fiber reinforced plastic draft is reproduced). As the forged bronze sculpture requires repeated forging and moving, the glass fiber reinforced plastic draft requires a high thickness and a strong internal skeleton. So far, the mold may break during the copper forging process, which will affect the progress and effect of the sculpture.
The third step: blanking and forging
Scribe and divide the reproduced glass fiber reinforced plastic draft to facilitate the cutting of the copper plate. The cutting of the copper plate can be done with electric scissors or a plasma cutting machine. After the blanking is completed, the forging part can be entered.
Step 4: Assemble
When the forging has reached a certain stage, you can enter the sculpture assembly process. The forged copper plates are assembled in sequence according to the glass fiber reinforced plastic draft. The places with small gaps can be welded with argon arc welding machines. When the gaps are large, fire welding can be used. The craftsman is required to process strictly in accordance with the glass fiber reinforced plastic draft, the splicing is not deformed, and the details are delicately processed. Here, attention should be paid to the strength of the internal skeleton of the sculpture and the firmness of the nodes.
Step 5: Coloring
After the wrought bronze sculpture is made as a whole, in order to facilitate the coloring effect and adhesion of the wrought bronze sculpture, it is polished and trimmed with a fine grinding wheel. Nitric acid is combined with sodium sulfide and potassium sulfide to make an acid treatment solution in a certain proportion to color the sculpture. This is the most important part of forged bronze sculptures. It must be successful once. If it is not handled well, it will become the biggest failure of the sculpture. If it is not handled well, it will be time-consuming and laborious to change it. After the coloring is completed, use the drawing layout to adjust, and finally spray the protective paint.
Step 6: On-site installation
The wrought bronze sculpture should be prevented from bumping during transportation and hoisting. When welding, pay attention to the connection and reinforcement of the embedded parts, pay attention to the wind resistance and anti-destructive strength of the sculpture, and finally carry out the complementary color treatment to the welding point.
The copper wrought process gives full play to the ductility of the metal sheet that can produce volume changes in space.