A look at bronze lost-wax casting
Bronze is one of the earliest metal alloys cast by humans. In fact, anthropologists date bronze castings since the Bronze Age nearly 5th Millennium B.C, a practice that has extended to Near and Middle East, Asia and Europe. In Africa, bronze casting was practiced only by the IXth century A.D. though an Egyptian tradition existed since 3 500 B.C.
Different metal casting techniques exist such as smelting, forging and direct cast method. One technique particularly holds attention when it comes to production of statues, sculptures and artwork in major civilizations, and it’s is the bronze lost wax casting.
The oldest example of this technique are the objects discovered in the cave of the treasure (Nahal Mishmar) in Israel, and date back to between 4 500 and 3 500 B.C. in what is known as the chalcolithic period. Through the millennia, bronze wax casting has been the technique used to produce true masterworks of art representative of different civilizations. It was there in the lion pendant from king Uruk IV in Mesopotamia (3500-2750 BC) in the Buddha image in Amaravati in South Asia, and the black bronze figure of Pharaoh Tutankhamun in Egypt.
A few of the mysterious bronze objects found in Nahal Mishmar Cave
But what is bronze lost wax casting?
The lost wax casting technique, also called precision casting, investment casting or cire perdue (from french) can be applied to gold, silver, brass, bronze or other metal alloys. It is a process of pouring molten metal in a mold that has been created by means of a wax model. The process can be applied from DIY to industrial scale, and is known to produce very accurate replication of artistic creations or models.
Even though in the details it may vary from one foundry or individual user to another, the main steps of the process of lost-wax casting casting are pretty standardized. A wax model is used to produce both a plaster negative and a clay model. The latter is scraped to the desired thickness of the future bronze layer, and then placed inside the mold containing the plaster negative. Hot wax is poured between the mold and the clay model, and once settled, molten metal is poured, which slowly replaces the wax which is drained and lost in the process, giving this one its name.
This process is explained in detail in the following documentary published by the Iris and B. Gerald Cantor Foundation:
This process, with some variations, may be used to produce from small DIY home projects to renowned masterpieces of fine arts. In between, arts and crafts from several countries have also capitalised on the artistic potential of this method to produce beautifully crafted décor accessories. Let’s have a look.
Lost wax casting in DIY projects
A short internet search is enough to show how popular lost wax casting has become among DIYers.
In many of home DIY processes, no clay model is cast from the wax model, but this one is used directly for the casting process. The wax model called the mold, is placed in a flask, and a plaster batter (similar to a pancake batter) is poured into the flask, covering the wax pattern. A sprue, or hollow tube, is attached to the mold, allowing for draining the wax once it melts, and force in the molten metal of choice, be it bronze, gold etc. Once the plaster has settled, the flask is heated, draining the wax, and the whole is placed in a home-size centrifuge or a vacuum machine to force in the molten metal. This process is wonderfully applied to produce small jewellery, rings and other fashion accessories such as belt buckles, and you can learn to do it yourself at The Spruce website.
Lost wax casting in fine arts
But the power of lost wax casting is not limited to DIYers. The use of bronze lost wax casting is a method of choice to reproduce the masterful details present in a sculptor’s work. Lost wax casting in fine arts has been used from ancient civilisations to contemporary artists. The ancient Greeks and Romans for instance used this method extensively in religious and artistic statuary, and the historian Pliny the Elder included discussions on the lost wax process in his Natural History in 77 A.D. In the Renaissance period, great artists had recourse to this process and to date, lost wax casting is used for reproduction of masterpieces, for instance in finishing Leonardo Da Vinci’s horse in 1999, the wax mold of which was produced by the artist in 1508.
Closer to us is one of the most famous representatives of bronze casting in fine arts: French sculptor Auguste Rodin. In artistic casting however, it often happens that due to the size of the works to be produced, sculptures are cast by parts, and then welded together, a process known as braising. Additionally, the polished finished sought for in artistic works justifies additional steps after casting consisting mainly of applying a superficial coating called a patina which works both as a protection coating and as a polish or colour. The result obtained after these processes is shown in these masterful sculptures of the iconic sculptor:
Rodin's famous bronze sculptures
Lost wax casting in arts and crafts
Today, besides the fine arts, the beauty of lost wax casting is appraised by artisans worldwide to produce beautiful works of arts and crafts for home, décor and fashion accessories. Sure, in all continents, this technique has brought its fruit. It’s in the African artisans however that lost-wax casting is most known, for the beauty and grace of the shapes in produces. Cire perdue is extensively practised in Western Africa. It is believed that this technique was introduced in this region by the 9th century A.D., in the Igbo-Ukwu (today Nigeria), in the 12th century in Yorubaland and 15th century in the kingdom of Benin (Dahomey).
Today in these countries, there is a whole sector of the arts and crafts industry dedicated to this technique, which contributes to the livelihood of entire villages. The media outlet Africa News produced an insightful documentary on this sector of activity in Burkina Faso:
Commercial lost wax casting in Burkina Faso often draws inspiration from femininity; let it be the woman figure, woman education or motherhood itself. Other popular subject-matters include nature, trees and animal shapes, which can be cast with precision.
We have included at Latitudes a collection of lost wax castings from Burkina Faso, many of which explore feminine beauty on different aspects. Enjoy!