Making of South Indian Bronze Sculpture using Lost-wax process

Making of South Indian Bronze Sculpture using Lost-wax process

The legacy of Chola bronze casting dates back to many centuries in making bronze sculptures using the lost-wax process.  The Sanskrit term for lost wax process is called “Madhuchehishthavidhanam”.  The lost wax technique is used to create sculptures in a variety of metals such as bronze, brass and other alloys.

Bronze is an alloy consisting primarily of copper, with additions of other metals like zinc, tin and nickel, making it an excellent choice for casting intricately detailed sculptures. Sculptures made of Bronze lasts hundreds of years due to its high strength, and corrosion resistance properties. The lost-wax process involves several stages to make a sculpture, and takes several weeks to months to get the final finished sculpture. Bronze sculptures are ancient treasures of southern India and each sculpture is one of a kind!

Steps involved in making the sculpture using lost-wax method:

Wax model: 

Traditionally, wax used in making the model uses a special kind of wax mix that includes bee’s wax or paraffin wax, along with resin and oil. This wax mix is perfectly suitable for making wax models that are stable in normal temperature and pliable/flexible when heated. A detailed model of sculpture is made using the wax, which is lost in subsequent steps making the model one of a kind. Heat is used on wax to carve, shape, and assemble intricate details on the wax model. 

Clay mold:

After the wax model of the sculpture is complete, a clay mold is made by covering all sides of the wax model with a casting clay. A secondary rough coat is also applied with the combination of clay, soil, and sand, reinforced with iron rods/wires to provide a stable structure that can withstand the weight of the sculpture. The clay mold is de-waxed by heating it  which melts away the wax, producing a hollowed out clay mold that retains the shape and details of the sculpture. The clay mold is now ready for molten bronze to be poured into it. 

Metal pouring:

Copper as the primary metal along with small portions of other metals are molten together in a crucible to make molten Bronze. This molten material is poured into the hollow clay mold. Various internal channels are created for the excess metal to flow out of the mold to avoid air pockets forming within the mold while pouring molten metal. The mold is allowed to  rest for several hours until the mold is completely cooled, after which the outside clay mold is broken to remove the solid bronze sculpture in its unfinished form.

Finishing:

The Bronze sculpture from the mold comes out with rough edges, support structures attached to it, that are painstakingly removed through manual steps and the sculpture is enhanced by chiselling, filing to add details to their face, ornaments, clothing etc. Finally, scratches are removed and buffed giving the sculpture a clean and refined look. Different finishes like antique, brown patinas, or vibrant fine-polish are applied as post processing steps.

Though the technique has evolved and tools have changed, the fundamentals of the lost-wax process used in South Indian bronze sculpture-making is absolutely unchanged, and still remains the same as in ancient times. Some important collections of South Indian bronze sculptures are displayed in the Thanjāvūr Museum and Art Gallery, and Museum in Chennai, India, and the largest number of bronze sculptures are found in various temples of southern India.

Nataraja wax model Wax model of Nataraja
Nataraja Bronze Casting - Unpolished/raw statue Nataraja raw Bronze Casting
Bronze Nataraja - Fine polish finish. Nataraja Bronze Casting - Fine polish finish

 

Bronze Statue Care

Bronze is an alloy consisting primarily of copper, with small quantities of other metals like zinc, nickel, and tin making it an excellent choice for casting intricately detailed sculptures. Sculptures made of Bronze lasts hundreds of years due to its high strength, and corrosion resistance properties.

Bronze statues generally require minimal care and cleaning, and methods vary depending on the finish of the statue:

Vibrant fine polish finish: Copper in Bronze can react to hard chemicals and we do not recommend using any hard chemical based cleaning.  The statue can be cleaned using mild soapy water with a soft clean cloth to remove any dirt, and dried using a clean dry cloth.  After wiping clean, the statue must be dried well, and a thin layer of natural oil or coconut oil can be applied.  Promptly wipe off any excess oil using a clean soft cloth, too much oil can attract dirt buildup in creases and edges. Application of oil prevents the metal from direct contact with moisture in air and helps preserve the shine. We recommend cleaning fine-polished Bronze statues once  a month, you may need to clean them more or less frequently depending on the moisture in your environment.  

Traditional cleaning methods uses lemon water mixed with tamarind paste, which is used to gently wipe the surface of the statue using a wash cloth, followed by rinsing the statue with plain water. Soap nuts boiled in water, and applying the resulting solution also helps to maintain the shine of Bronze statues.

Brown patinas and antique finish: Statue that have an antique finish or patina finished already have a protective coating on them, and almost maintenance free compared to polished Bronze.  Statues with antique or patina finishes can be cleaned using a wet soft cloth using mild soapy water to remove any dirt or stains, and coconut oil or any other natural oil can be applied after statue is dried. Any excess oil should be wiped off using a dry soft cloth.  Cleaning these statues a few times a year would be sufficient, or as needed depending on the environment.


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