Casting Processes at Talos Art Foundry

Talos Art Foundry casts bronze sculpture using the lost wax technique (cire perdue). Lost wax casting was first used by the Ancient Egyptians around 2500BC and the technique remains largely unchanged.

This detail from the tomb of Rekhmira at Luxor dated 1500BC shows foundry workers stoking a charcoal furnace using bellows tied to their feet and lifting a crucible of molten bronze from the fire using long poles much as we still do today.

Mould Making

Mould making: the first step of the bronze casting process is to make a mould of the artist’s original sculpture. We use modern Silicone rubber moulding materials so sensitive that the artist’s fingerprints can sometimes appear in the finished bronze sculpture. The bronze chair in ‘Journey’s End’ by Richard Atkinson-Willes was moulded from a real chair and is indistinguishable from real wood – until you try to lift it!

Cire Perdue

Cire perdue: a wax copy of the artist’s sculpture is made by pouring molten wax into the silicone rubber mould and allowing it to cool. A network of wax pipes with a pouring funnel at the top is attached to the wax sculpture, then the whole thing is coated in a ceramic casting material, which dries in the air. This ceramic mould, with the wax sculpture still inside, is then placed in a kiln and fired. When heated the wax runs out, of course, leaving a void – hence the name ‘lost wax’ or ‘cire perdue’.

Casting

Once all the wax has run out, the ceramic mould is buried in sand with only the pouring funnel showing: this is where the molten bronze is going to be poured in. The bronze is melted in a furnace in a pot, or crucible.

In this painting dated 1500BC, Ancient Egyptian foundry workers are shown pouring molten bronze info a mould through cup-shaped funnels – exactly as we do today.

Fettling and Chasing

Molten bronze is poured into the ceramic mould through the pouring cup, and solidifies almost instantly. Once cool, the ceramic mould is broken, revealing the bronze sculpture inside. Large sculptures are cast in several sections and then joined together and finished by ‘chasers’.

This Athenian red figure vase from 500BC shows a foundry man tending his furnace, while on the right, a bronze figure is about to have its head re-attached by a chaser with a large hammer. There are foundry tools hanging on the wall behind – and hands and feet belonging to another sculpture. The same techniques are still used today, though protective clothing has come on a bit!

Patination

In this picture from a Greek vase dated around 500BC, ancient Greek foundry workers are polishing a monumental figure using curved burnishing tools.

There is evidence to suggest that once finished, ancient bronzes were brightly painted – the antique patinas that we see today are simply the effect of time and the elements on the bronze during the centuries since the paint faded away.

To reproduce these antique patinas, the team at Talos use a selection of salts combined with heat to accelerate the bronze’s natural ageing process. We encourage artists to take part in the patination process – like the artists overseeing the burnishing of the heroic figure in the ancient foundry scene above.

Sculptor Diana Pattenden takes us through her process, from sculpting her cheetah in clay, before handing it over to Talos to mould then cast in bronze.

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