| e has been the most sought-after metal for cast | | | | the solid nature of the originals. The other reason |
| metal sculptures in the bygone years. Bronze | | | | is the rigidity of the originals at the time of |
| alloys have a desirable and unusual property to | | | | removal of plaster mold. That’s why; the |
| expand slightly prior to their setting. This helps a | | | | original is cut off into thin, long pieces and |
| great deal in filling every corner of the mold. Their | | | | separately molded. At times, a number of molds |
| ductility and strength causes them to be molded | | | | are required for recreating the original structure. |
| into any form. However, bronze has a basic | | | | Wax: After the completion of latex-and-plaster |
| disadvantage of not being durable. Hence, there | | | | mold, the pouring of molten wax takes place. |
| are hardly any traces of ancient bronze statues | | | | Then, swishing is carried out till a uniform coating |
| found. Bronze casting generally takes place by a | | | | is obtained. The thickness of the coating is 1/8 |
| process called lost-wax casting. Though, centrifugal | | | | inches. The mold’s inner surface gets |
| and sand castings are also employed, around 90% | | | | covered by it. This process is repeatedly |
| of bronze casting takes place through lost-wax | | | | executed till the preferred thickness is attained. |
| casting. | | | | Wax removal: Artwork’s ‘hallow |
| Lost-wax method: Lost-wax casting, in the | | | | wax copy’ is detached from mold. This |
| industry, is better known as investment casting. It | | | | mold may be reused by the artist for making |
| is costlier than die and sand casting, but outshines | | | | more copies of wax, but its use gets restricted |
| them in terms of accuracy. It is easily possible to | | | | due to frequent ‘wear & |
| make complicated structures through | | | | tear’. Around 25 copies can be made for |
| ‘lost-wax casting’. The process | | | | tiny bronze artworks. |
| can be described as follows: | | | | Chasing: The chasing of each copy starts. Rubbing |
| Sculpting: First, the original artwork is created by | | | | of the marks is done by a hot metal tool. The |
| the artist from clay, wax, or some other material. | | | | marks showing ‘flashing’ or |
| Mostly, clay (oil-based) and wax are used due to | | | | ‘parting line’ are rubbed out. |
| their property of retention of softness. | | | | Spruing: The spruing of copy generates paths to |
| Mold making: Majority of molds consist of 2 | | | | flow (for molten bronze) and causes air to move |
| pieces, along with a shim placed between 2 halves | | | | out. |
| at the time of construction in order to put back | | | | Slurry: The dipping of sprued copy into a liquid |
| the mold accurately. Keys are kept in the shim. | | | | silica slurry, and then into sand-like |
| The small sculpture molds generally consist of | | | | ‘stucco’ takes place. This process |
| plaster. Fiberglass can also be used. To have the | | | | is repeatedly carried out till the coating attains |
| minute details preserved on the surface of original | | | | thickness of at least ½ inch. |
| artwork, there exists a mold inside. It is made up | | | | After these steps, the out-and-out processes like |
| of vinyl, silicone, or latex supported by plaster | | | | burnout, testing, pouring, releasing, metal chasing, |
| part of mold. Generally, the destruction of original | | | | and patinating are carried out. |
| artwork takes place during making. This is due to | | | | |