Lost wax casting method - first the "lost wax" and "casting" that separate the two terms, the process is: the design of good works, regardless of three-dimensional or semi-relief sculpture, sculpture is complete, the silica gel plus an appropriate proportion of silicone oil, oil paint brushes brushing the sculptures layered evenly, so that the average brush over silica gel sculpture.
By works of different sizes, ranging from silicone clotting time, usually about 2-4 hours, huge pieces even need 10-24 hours. Silicone and silicone oil must have an appropriate ratio in order to have good braking and durability. On the contrary, anxious to complete the silicone mold, plus an excessive amount of silicone or hardening agents, although silicone can greatly shorten the coagulation time, but it will not cause silicone scalability. Wax in the form of demolition work, the work can easily pull off the wax form, can not make fine work. And the brittle mode of silica gel, using a low frequency, it must have the patience to wait for the natural shape silicone mold.
Another effect of the silicone mold toughness, ductility of the key factors is the need to be adjusted several times layered silicone oil is equally good in the brush around the sculptures of varying thickness. Although the works of different thickness, but shall be uniform so that the silicone mold forming a layer dries, paint the second floor, third floor, until they reach a certain degree of uniformity of coating silicone mold, this is the creation of a suitable, durable good model.
In accordance with standards such as the operation is completed, the wax cast from the fire is completely melted out, according to plaster molds to form hollow wax, this is the negative mode, this process is known as the "lost wax." At this point process, precision casting precision metal materials, has completed about 80% of the process. As long as the metal material and then completely melt into liquid, into the fire resistance of hollow cast, the natural cooling even if you¡¯re done, the failure rate is very low. However, glass art process, a good wax removal process be completed until 30% of the entire process.
Casting, usually many low-temperature materials such as aluminum tin alloy, the mold for the steel, rubber and so on. Use of motor speed, the material pulling away from the centrifugal casting mold forming around yearned for small items. Sand casting, by regular spinning mixed into the mold, using materials of steel alloy, aluminum, copper alloy, zinc alloy, glass, etc., the material melting, casting to the sand mold, condensation forming can, for medium and large pieces or large pieces of castings. The materials used are gold and steel casting, copper and aluminum, stainless steel, steel or other precious metal alloys and glass and so on. Fire-resistant plaster mold is completely melted material by casting material, the natural vertical flow molding. The difference is that as long as the general metal forming natural or not natural condensation can. The glass either machine forming, sand casting, lost wax casting, need to be formed in the casting immediately after the ejection into the cold furnace Xu, Xu by casting different sizes to be cold cooling time for the complete release of internal stress glass material before Casting does not result in condensation forming, a sudden crack.
Sculpture we call the positive mode; The use of silicone coating on it, molding, called negative mode (internal hollow.) Select the appropriate line, using the local utility knife to cut open silica gel, the sculpture out, then the line of good silicone mold to form a hollow mold. Will reach the appropriate melting point of wax, suitably into the silicone mold, filling model, and then still waiting for the wax forming natural cooling. Which is not used in ordinary candles or paraffin wax, perfect and too soft are not appropriate, will be careful not to original works of beauty. Strong modification of the wax will be hard, too soft wax can not be formed. The temperature will melt the wax can not flow to less than subtle, the temperature is too high, disadvantages, so the wax melting temperature of the need to control properly.
Cooling molding wax out from the silicone mold, have to be careful form removal. Silicone mold in the open when the need to gradually pull down, minor subtle experience, you need to slowly open, so that wax complete. Accidentally ripped the need to reconnect, and sometimes wax will make the angle asymmetry, loss of beauty. Smooth out the wax models and sculptures the same, is the positive mode. At this time the surface of the wax mold slightly flawed, it needs tools to repair. The parting line, porosity and other fixed fill level, if broken, are also repaired with wax at this time, the process for the repair wax. Completion of repair wax wax, plaster model can be carried out irrigation. Plaster cast is usually used, not the general cast, but made of different materials in accordance with, the choice of a dedicated fire-resistant gypsum. Difficult to accomplish with the wrong creative works, and even cast does not come out, or knock not open. In addition, the proportion of water is also very critical. Add less water, not covered with wax at the full, detailed plaster Yi solidification, can not make a good work; water Cadogan, the plaster is too loose strength is not enough, not into the furnace sintering, surface texture and minor plaster off, they can not operate. Therefore, an appropriate proportion of water required by the deployment of plaster, filling a good fire-resistant gypsum, in the shade to air dry.
Wrap the dried wax fire-resistant gypsum, pulp mouth down on the steam in the bucket, the door closed, high temperature steam spray to prevent assault. Adjusted the valves, the steam into the use of high temperature steam, the fire-resistant gypsum gradually melted wax in slowly drained until the fire-resistant gypsum mold no residual wax, you can stop. Works of different size, operating time is not the same. As mentioned above, also should pay attention to the proportion of fire-resistant gypsum transfer, if the proportion of properly, the high-temperature steam, it is easy to crack model can not be used.