Lost-wax casting, step by step: from clay to bronze

Lost-wax casting — cire perdue — is thousands of years old and still, in our experience, unbeaten for capturing fine devotional detail in bronze. It's slower and less forgiving than sand casting, but the surface fidelity is what makes a Nandi or Nataraja read as hand-sculpted rather than machine-poured.

1. The master model

We start from an approved clay or digital maquette. For a fully traditional build, a wax replica is hand-worked over a clay or wax core; for larger or repeat pieces, we may 3D print a wax-analogue master instead — the casting method downstream is identical either way.

2. Investment and dewaxing

The wax model is coated in layers of ceramic slurry to build an investment shell, then fired in a kiln. The heat melts the wax out through a channel — hence 'lost wax' — leaving a hollow ceramic mould that is the negative of the piece.

3. The pour

Molten bronze, heated past 1,000°C, is poured into the still-hot ceramic shell. This is the point of no return in the process — timing, temperature and shell integrity all have to hold, or the piece is lost.

4. Breaking out and chasing

Once cooled, the ceramic shell is broken away to reveal a rough bronze casting. From here our chasers spend hours to days — depending on scale — filing sprues, refining texture, and sharpening detail that the mould alone couldn't deliver.

5. Patina

The final colour comes from chemical patination — heat and acid solutions applied by hand to build verdigris, antique gold or matte bronze tones, then sealed for indoor or outdoor display.

It's a process where almost every stage is irreversible, which is exactly why it's still done by sthapatis who've spent years learning to read a shell before the pour, not just after.