The first step in the casting of a bronze statue is to create a replica of the piece out of wood or clay. Secondly a lubricant such as oil is used to coat the statue followed by a thick layer of silicone rubber.
After the rubber has hardened – a process that can take 24 hours – the coating can be removed from the replica, leaving a detailed mould.
Next, the mould is filled with hot wax. After being left to cool, the mould is taken off to leave a wax sculpture.
After attaching the wax model to a device called a screw that channels molten bronze via a series of fine channels, the mould is dipped into a ceramic solution and covered with powdered silicon to strengthen it.
The internal wax mould is then melted in a steam oven, while the ceramic one is fired to provide the final mould. Bronze is heated to over 2,000 degrees Celsius (3,630 degrees Fahrenheit) prior to being poured into the mould, solidifying in 30 or so minutes. Lastly the ceramic layer is chipped and sandblasted away to reveal the bronze statue within.