Foundry

Donald has used various foundries around South Africa and in 2010 he set up his own foundry which produces only his work.  The foundry employs a team of a dozen highly skilled artisans all specializing in different areas of the casting process.

Casting Process

Once deciding on an animal to be sculpted, an intense anatomical and behavioural study of the subject is undertaken including its skeleton and muscles.    This ensures that the dimensions of the sculpture are accurate and realistic.

A polystyrene or wire “armature” is formed into shape, duplicating the animal’s anatomy.  This is then covered in sculpting wax and modelled into shape. The finer details are again studied and reflected faithfully to produce the artist’s final wax model.  

A silicone mould is made from the original wax model. This is done by painting four layers of silicone rubber onto the model and then covering it in a fiberglass jacket.  The fiberglass jacket is opened and the original wax model removed, to reveal a perfect negative.  A thin layer of wax is painted into the mould and then joined back together.

Feeders and risers are attached to the model through which the bronze will ultimately be poured.  

The wax model is then dipped into “liquid glue” and covered in layers of fine zircon sand and course sand to create a ceramic mould.  The mould is left to dry and reinforced with wire.

The ceramic mould is immersed into hot water to melt the wax.  Wax being lighter than water rises to the top and leaves the hollow ceramic mould.  

The hollow ceramic mould is baked in the “hot box” which reaches roughly the same temperature as the molten bronze.  This firing is important to burn out any left-over wax, as well as to harden the ceramic.

Our furnace, which is heated with Diesel, holds a clay crucible containing 40 kilograms of bronze.  The temperature reaches 1200 degrees Celsius and flux powder is added to the molten bronze.  This combination forces impurities to rise to the top which are scraped off leaving pure bronze.  The molten bronze is then poured into the ceramic mould.

Once the bronze has solidified and cooled down, the ceramic is cracked off to reveal the raw bronze.  The sculpture is sandblasted to remove any remaining ceramic.  The piece then goes through a quality check process.

A combination of chemical treatments and heat are applied to produce a natural oxidizing to create the desired surface colour and texture which is known as patination.

The bronze is coated in a wax that seals the patina and is mounted onto a base or lined with leather or felt.

 

 

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