Friday, March 30, 2012

Artists Working with Bronze

Bronze

One of the materials with which Burkinabè artists work is bronze. I checked out what bronze is supposed to be and it seems the term is used for any of a number of combinations of copper with other metals.  Originally I think it meant copper and tin, but there are a number of other combinations that are still referred to as bronze. There are several streets in Ouagadougou where you find collections of shops selling things made from bronze, and bronze figures of various types are found in the tourist gift shops around the country.

I had a chance to follow the making of a bronze figure from start to finish.  In this example, the artist, Mathias Kaboré, began by softening a lump of bees’ wax over a charcoal fire.
 Then he formed a model of a little elephant. 
 The next step was to make a mold into which the bronze would be poured.  To do this he mixed clay and donkey dung.
Then he covered the wax model with the clay mixture.
 Here is the model after several layers of clay have been added.
 After the clay has dried for several days, he and some of the other artisans built a small fire and put some molds they had made, including the little elephant, close to the coals.
A while later they poured out into a can the wax that had been the model, so it could be used again.  This method is called the lost wax method, because you lose the wax before you put the metal into the mold.
While the molds were heating, Matthew put some figures that had been cast that did not turn out right, some copper wire, and even an old door handle into a clay pot.
This hole is their forge, the place where they melt the metal
They filled the hole part way with charcoal, threw in some embers from the fire, and added the pot.  Then they covered all of it with more charcoal.
To get it hot, one of the fellows would sit in the shade of a trap and turn an old bicycle wheel. The belt around the wheel goes around a small axel in a fan that blows air into the forge.   
 They claim the temperature in the forge reaches 1000 degrees Celsius.  I didn’t have any way to check the temperature, but it sure was hot.
While the various metals were melting together in the forge, they built up a fire over and around the molds.  This was to get them hot so that they would not crack when the hot metal was poured into them.
Finally the metal was all melted together, and the clay pot was removed from the forge. They used a ladle to skim off the impurities like little pieces of charcoal, and them ladled the hot metal into the molds.
After only a short time (about 15 minutes), they broke off the clay to reveal the metal figures.
I had to go back another day to see the final step. This consists of scraping off any remaining clay and polishing the figure to a shine with a file as this artisan is doing to a lion he made.
Here is the little elephant that emerged from that clay mold, after it was polished.
Now let me introduce the men who showed me how this is done, posing with some of their creations.  I have listed the e-mail addresses of the two who gave them to me, in case anyone is interested in contacting them.

Mathias Kaboré, KAMAKA46@YAHOO.FR

Paul Zongo

Jean Baptiste Balima Jean.Balima@yahoo.fr
Soumaida Kièmtoré

Nassirou Kièmtoré
Other Bronze Methods

There is a slight variation on this theme, if you want to make a lot of things that are very similar. You begin as Mathias did, above, but instead of covering your wax figure with clay, you cover it with plaster of Paris. Then, you cut through the mold to remove the wax figure.

Now you have a mold you can use over and over to make wax figures that you cover with clay, dry, bake out the wax, and fill with bronze, as you saw in my story above.  The virtue is that you do not have to model the figure each time.

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