Metal - Brass is used, which is an alloy of Copper and Zinc. Since pure Copper is a soft metal and is not an effective material unless strengthened as an alloy.
Beeswax and Industrial wax - This is mixed with groundnut oil and binding resin to make a mixture called 'rar'. The initial mould is crafted from this.
Oil - is rubbed onto the working platforms to avoid sticking.
Sand and clay - to make a cast over the wax form.
Cow dung cakes, coal and firewood - to heat the entire form for the wax to melt and also to heat the metal.
Kerosene - for the small burner, which is used to heat the tips of the tools.
Metal wires - as reinforcement for the clay model in bigger models.
Traditionally, beeswax used to be the raw material for manufacture of products in which lost-wax casting method was used. But the cheaper and quicker alternative of industrial wax is presently taking over. This is resulting in more wastage than natural wax, as some of the industrial wax gets burnt away during the process.
Tools & Technology
The tools required to execute the lost - wax technique are as following:
Dhatiya - a wooden bat used to beat the wax slabs.
Patla - A sturdy flat wooden surface, upon which the wax is worked.
Athali - wooden sculpting and molding tool.
Chisels, hammers - for making patterns and shapes with wax, breaking clay moulds and subsequently polishing the metal.
Pointed mace rolling pin - used to roll wax strips into thin threads.
Kerosene lamp - to heat the tips of the tools while working on the wax models.
Tongs and holders - To heat wax and pour molten metal.
Kiln - to melt the metal.
Press - A longitudinal metal slab with patterns in negative space marked on it. Wax strips are run through it, pressed together and they quickly rolls out as patterned strip.
Stamp tools - These are made by the craftsmen themselves for stamping on various patterns onto the mould.
The Rar is heated and when it reaches a malleable state, it is used as the modeling material. In case of larger objects, a clay base is made, over which this wax mixture is coated and given the finer shapes.
The wax is melted and repeatedly heated over a period of two days and prepared. Available in the form of flat chunks, they are melted according to the amount needed. The wax is shaped into the desired form.
Sometimes, the entire form is made out of one piece and other times the limbs or other elements are made separately and fused to the main body. The ornamentation is made on wicks of rolled out wax and then added to the main form. Intricate patterns are made on wax using fine tools and stamps.
After the mould hardens, a thin layer of local red soil is applied so that it percolates into the finest of designs. A layer of fine sand is applied so that it percolates the thinnest of patterns. Then a clay based paste is applied over this. Another thick coat of mud mixed with cow dung is then applied externally over the form. This last coat involves application of clay and sand (bajari). Here, the sand act as strengthening agent and prevents the mould from breaking open when heated. These steps of coating the mould with different mixtures takes up to 7 days.
Sometimes, in case of bigger sculptures, metal wires are used as reinforcements. So that the clay does not crack open while heating. This is then kept in sun till it dries. The mould is then heated over burning firewood and is covered with cakes of cow dung. The wax melts and flows out through the hole left open while the clay cast was made. This wax is collected in a container filled with water.
Molten metal or brass is then poured directly into this cavity. This non - ferrous metal casting takes over 15 - 20 minutes to complete. After the metal solidifies, the external covering is broken using hammers. The clay is wiped off and this is then again dried in the sun. Electric polishers, chisels and other tools are used to add a finer finish to the piece. Acid treatments are given to obtain antique finishes.