African Lost Wax Casting
African Lost Wax Casting is a process that started several years ago around 900 AD and mostly in the West African regions. Ancient "Lost Wax" bronze castings have therefore been around for quite a long time. These castings represent the social standings of the people who do them. Their religious views, culture and traditions can also be deduced using what they mold. That is, what kind of molds, shapes and art are they casting. As ModernSculpture.com (2000) puts it, the society may have changed in the recent past where the way of life has changed, religious views and technological changes have occurred, but this process except for a few changes has remained consistent.
The process of lost wax casting is slowly changing and adopting newer and much easier methods of casting. It is for this reason that most foundries apply it to plaster, stone or wood before transforming it to bronze. Lost wax casting therefore will involve making a model of a specific shaped jar or item by cutting out the shapes and designs required or the preferred decorations using wax from honeybees. This is then slowly and carefully smeared with clay both in the inside and outside and then bronze pins are stuck through it to fasten the outside clay to the inside one. When the clay has dried up it is heated up to allow the wax to melt and come out. Molten bronze is then poured into the mold and cooled for some hours. Afterwards, the clay is then broken both from the inside and the outside (The Metropolitan Museum of Art 2011).
The process of lost wax casting involves the following steps. According to Lost Wax Found Bronze (2007)it begins with creating a clay model using preferably oil based clay that does not stiffen easily allowing ease of work without worry. This kind of clay will also allow decorations and alterations to be made easily. This is referred to as a Marquette. If necessary a wooden or wired armature can be used inside it to hold the clay in place.
In the next step the Marquette is smeared with silicone rubber forming a mold of the original Marquette before it is then allowed to dry up and harden, and then it is covered with plaster. The rubber and plaster are later removed. When the plaster jacket is hard, the rubber and plaster are removed in two or more sections, depending on the size of the sculpture. Once the plaster and latex mold is done, molten wax is then poured into it and swished around until an even coating covers the entire inner part of the mold consistently.
The next step is what is referred to as ‘Wax chasing’ which means joining wax pieces together to form a full sculpture. The seam-lines are removed and trimmed and the wax pieces are fitted for perfect alignment. At this point the artist is expected to inspect the sculpture and make changes where necessary or approve it if it has met the requirements. Some rods called sprus or gates are put in the sculpture and a large vessel, jar or funnel is then attached to one side of sculpture so as to receive molten bronze in. In this stage, care must be put in place in ensuring that there is even distribution of bronze. Perfect conditions like ventilation and shrinkage factors must also be considered (Americanbronze.com 2011).
The wax sculpture is not strong on its own and therefore there is need to reinforce it to stop them from falling off. This can be done by building a hard cover or shell all over the sculpture. In the ancient times, a plaster sand and water was used but with the inventions and development of technologies it has been improved into ceramic shells which make the work a little bit easier. Ceramic shelling involves dipping the wax casting into liquid several times to create several layers. As AsuBronze.com (2012) explains, after this is done, it is placed in an oven or fire which allows the wax to melt. A hollow ceramic shell mold is formed and then molten bronze is then poured in. It is then cooled for hours before the shell is broken to expose the bronze and then polished to the correct requirements.
At this point the metal must also be chased or cleaned out to correct defects through a sandblast. The sculpture is also polished and color is added through a process referred to as patination. This is blending several chemicals and techniques with a variety of colors (Sculpture by Daniel Rotblatt 2007).
Just as the same way bronze has been of use for centuries in Africa and the world at large, lost wax casting has also played a major role in the region. It is a practice that has become a source of income for many people and also a source of revenue to the relevant countries. Lost wax casting also combines the skills associated with both metalworking and pottery which leads to unique products that suits every taste. Accuracy is also achieved because molding using the wax allows for correction to take place before the final product is made. Landmarks have been molded through lost wax casting and other prominent pieces of art like theBronze head, kingdom of Benin, and Nigeria in early 16th century which is now at Metropolitan Museum of Art in New York (A World History of Art 2012).
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