Waxed eloquence

Print edition : November 19, 2010

The "lost wax" method of making a bronze is explained here in a series of photographs taken at the workplace of Srikanda Stapathy at Swamimalai near Thanjavur. The entire process takes several months to complete. Step 1. Wax moulds of all the parts are created and fused together.-PHOTOGRAPS BY M. SRINATH

A step-by-step account of the process of making a bronze.

MAKING bronzes with intricate workmanship is a demanding process that lasts several months. It becomes doubly difficult when the metal image has many hands, each holding an object or making a specific mudra. The hands, be they four, six or eight, have to be distributed proportionately with enough gap between them, and fusing them with the torso demands great skill.

Although they are called bronzes (which is a Western coinage), the icons are actually copper alloys, that is, copper mixed with gold, silver, lead and tin. They are called seppu tirumeni (copper images) in Tamil.

R. Nagaswamy, iconographer of international repute, who has authored several books and monographs on South Indian bronzes, says, For over six centuries, during the peak of this [metal] art, the Pallavas and their successors, the Cholas, produced work after work of astonishing beauty and aesthetic refinement. In the skilled hands of the anonymous artist, metal became a material of amazing versatility ( The Great Tradition, Indian Bronze Masterpieces, Festival of India, 1988).

STEP 2. THE WAX model is coated with a paste of clay mixed with fine river sand, which is called 'earthen mould'.-

While the images made during the Pallava period are hollow, those made during the Chola reign are solid cast, called ghana.

All the metal images in Tamil Nadu were made by the cire perdue, or lost wax, process. Before setting out to craft the icon, the master craftsman recites a dhyana sloka and visualises in detail the metal artefact he plans to make. He then makes an image out of wax, maintaining the proportions.

If the image has eight arms, the craftsman makes each arm separately and fastens them one by one by applying heat to the point where they join. He may fasten the two main arms first. As for the other arms, there is no fixed sequence in which they have to be attached; the craftsman decides it according to his predilection. Rods are propped up between the hands to maintain the distance between them. The legs are also made separately and fused with the wax torso.

STEP 3. THE earthen mould is dried in the shade until it is rid of all moisture.-

After the wax image is made, the craftsman applies over it two or three coats of clay mixed with fine sand. This clay coating is allowed to dry in the shade for nearly a month.

When the clay is dry, the sthapathi creates an orifice, several centimetres in diameter, on the back in the central part of the torso of the image and another one in its head and a third in one of the legs. If the image is a big one, orifices are created in the hands too. The image is then placed in fire so that the wax inside melts and flows out through the orifices. Since the wax runs out, it is called lost wax method. The clay mould that remains is kept face down in a pit and fastened to the earth with metal wire.

STEP 4. THE mould being heated after it is fastened with copper wire.-

In the next stage, the sthapathi melts the amalgam of copper (93 per cent), gold, silver, lead and tin in the required proportion. Judging from the colour of the red hot liquid, he knows when to pour it inside the clay mould through the central orifice on the back of the image. He has to pour it fast, taking care to ensure that air bubbles are not formed in the molten metal inside as they can result in holes in the image.

The molten metal runs into all parts of the mould and overflows from the orifices on the head and leg. This is an indication for the artist that the molten metal has travelled into all parts of the body and he will allow a little more to overflow, Nagaswamy said.

STEP 5. THE wax inside the earthen mould melts and flows out.-

While this is the method adopted for making small images, for a big image the craftsman reinforces the clay mould by tying copper wire around it before drying it. One more coat of clay is applied over the wire. Nagaswamy explained, This is done because when the liquid metal is poured inside the clay mould, the sudden rise in the temperature inside will give a kick and crack the mould.

STEP 6. THE metals are heated in a crucible until they form an amalgam, which is then poured (above) into the mould.-

After some hours, when the sthapathi is sure that the metal has solidified properly, he breaks the clay mould into pieces and brings out the metal image inside. This technique yields a solid image called g hana. When a hollow image has to be made, a clay mould of the image to be created is done first. It is given a wax coating of 5 cm thickness, which is then covered with clay. So, when the bronze is finally cast, the clay remains inside. It is not, therefore, really hollow. While the sthapathi in Tamil Nadu chisels the embellishments on the image after it is taken out of the mould, his counterpart in North India works on them while casting the wax mould itself.

STEP 7. THE rough metal image obtained after the molten metal cools and solidifies in the shape of the mould.-

As years go by, these bronzes develop a greenish patina, which acts as a natural protector of the metal. The patina forms because of the suffocation the bronze undergoes when it is kept in cellars. The metal may also develop what is called bronze disease, which eats into the metal. The metal contracts this disease because of oxidation when it is exposed to the atmosphere. This can be treated.

STEP 8. THE completed metal idol being given the finishing touches.-

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