Back to the Bronze Age

Ancient Craft is still Alive in Art Casting

 

Who does not know them, the bronze equestrian statues that bear witness everywhere to the fame and heroism of warlike commanders and kings? But hardly anybody knows how these bronze statues are made. In Frechen-Bachem, a little place near Cologne, Germany, we have taken a look at an art foundry. The craft is still the same it was in the times of our grandfathers. Everything is made by hand here. Large computer controlled machines that function without the aid of man do not exist here. Tools are merely aid. Dexterity and eye are the essentials.

 

Piece by piece the model is embeded into pure quartz sand. Thus a form exact to the tinyest detail is created which is used as a mould later on.

Every movement has to be precise, because when handling the glowing metal mass, carelessness can be dangerous to everybody. But let me come to the point now: how is a work of art made, how are a dancing faun or a warlike commander formed out of a bronze lump?

First, there is the artist who designs the future workpiece or piece of art because the art casters see themselves as craftsmen and not as artists. Their work begins once they have the model made of plaster, wood or clay. First, this model is embeded into a sand-filled casting box. We know this principle from our days of childhood when baking cake in the sandbox. Just like in those days, the adhesiveness of the sand plays an essential role. Pure quartz sand meets all requirements: it is so fine that it penetrates even the smallest gaps of the model, it sticks and adheres well which is important for the following work steps.

 

After every workstep, the finished parts of a form are sprinkled with forming powder, which gives stability to the form and facilitates the separation of the individual pieces later.

After modelling the form, the model is taken out cautiously.

 		Once the model is embeded in the sand, it has to be stamped thoroughly. In the case of rugged forms or forms with separate parts, several pieces have to be stamped. This is feasible because the sand gets so dense that it can be taken off after stamping. Marl and forming powder serve as adjuvants and separators of the individual pieces. Two of such halfs of the mould are made, then the model is taken out, casting channels for the metal mass are built in and the mould is shut with iron bands. Stop - first the sand form has to be put into the drying oven for four to eight hours - the temperaturein there is approximately 500° Celsius in there.

 

The oil - heated oven heated up to 1400° Celsius.

In the shape of such lumps the bronze is put into the melting pot.

 		While the big melting furnace in the ground is prepared and the pot is filled with metal and slowly heated up to roughly 1400° Celsius, I ask the master craftsman about the composition of the metal. I get a mischievous smile: "That´s a secret of the family! Just as a good pastry-chef would never tell the ingredients for his special gateau, it all depends on the mixture here, too - and that is a special recipe." But then he does reveal as much as this: Copper and tin makes bronze, as we remember from school. Add a little silver, a little aluminum - but merely now and then. The business counts on regular customers, which are for the most part artists that work in the sacral field. Church doors, portals, statues of saints, chalices, grills for the chancel are often made of bronze cast. But also the "Klüttenmännerbrunnen", a well in the brown coal town Frechen or the statue of the black fighter for freedom Martin Luther King, that has been shipped over the pond to Springfield, were made in Schnitzler´s factory.

 

Once the bronze has reached the right temperature, the actual casting procedure can begin. The expert can tell it by the so - called "mirror".

 

Glowing bronze

 		In the meantime, the metal in the round graphite pot has reached melting temperature. The men need no thermometer, the expert can tell the right time from the "mirror" of the metal surface. The bubbling mass must have a temperature of about 1400° Celsius. Now there is no time to waste for tiresome journalist questions, now things have to be done fast. Somehow the scenery reminds one of limbo. The reddish glowing metal shrouds the entire room into an eery light. The men´s faces are concentrated and tense as they place the huge shears in position, by means of which two of the men lift the casting pot out of the oven. If much material is used, the block and tackle take the place of human strength. The prepared moulds are already pressed together by iron bars and are standing lined up ready for use. Within a few seconds, the men shunt the pot over the tiny looking casting openings, nothing is spilt. As glutinous as syrup the reddish glowing mass flows into the forms. The experts call this "pouring off".

Heavy work: casting procedure in smoke and heat.

 

Uneven patches and edges are eliminated by hand.

 		Now the forms have to cool down until the metal has reached rigidity. Only then they can be opened and the cast piece is taken out of the form by means of tongs. Then the workpiece is sandblasted and the casting channels are knocked off. Possible cast joins are ground away, because later the transitional line must be invisible. The finishing touch is put to the pieces by chasing and then they stand there, lined up and shining - the works of art are finished. That is, they are not really finished yet, because the typical patina and colouring of all bronze objekts must still be applied. That is done with some kind of acid, the master craftsman tells me, but also in this case of exact recipe, as said before, is a secret of the family.


Text : Hildegard Ziskoven

Photos : Gerhard Zerbes

Beautiful down to the detail: the "Bartmannbrunnen" in Frechen near Cologne, Germany.

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