Creating a sculpture is a very long and arduous process. Given the necessary investment, it is also considered a risky enterprise for an artist. Bronze casting in particular is an expensive matter. The entire process of a sculpture, from construction to bronze, takes an average of three months and larger sculptures can sometimes take six months. The maximum number of poured editions of a small sculpture is 12 and of a large sculpture is 7. That way, the sculpture remains exclusive.
Nic Jonk always began creating a sculpture by welding an iron frame: the construction. The iron pieces were bent and welded to each other, making the first contours of the sculpture visible. Before the clay was applied to the construction, iron wire was wounded around small pieces of wood and carefully affixed to the construction.
Afterwards, the clay was applied layer by layer to the construction. When there was sufficient clay on the construction, Nic Jonk began modelling. In the earlier sculptures, he mainly modelled by hand. Later he increasingly used a round clay club that made the clay model even and smooth.
Afterwards, the sculpture was divided into segments by means of copper tins that were pressed straight into the clay. Iron reinforcement was then laid against the tins to ensure the sturdiness of the plaster mould. Subsequently, the first thick plaster layer was applied to the clay sculpture. This plaster layer was called the negative.
The plaster layer, sectioned into moulds by the tins, was removed piece by piece from the clay and then the clay was very carefully removed from under the plaster using filling knives. The plaster moulds or negatives taken off the clay were subsequently cast with a thin layer of plaster combined with some flax for the necessary strength. This second plaster layer was called the positive.
Before the positive plaster layer was cast, the negative mould was first dabbed with potash. That made it easier to later chisel the negative away from the positive. The positive plaster layer also received a different colour so it could easily be distinguished from the negative layer. This reduced the risk of damaging the positive layer when chiselling.
The cast plaster moulds were affixed to each other by means of flax soaked in plaster. Afterwards, the negative plaster layer was carefully removed with a hammer and chisel. Lastly, the positive plaster model was retouched and was then ready for bronze casting.
Pouring the bronze is also an arduous process. The plaster model is placed in a casting box with casting sand, creating a print of the sculpture. Subsequently, the entire sculpture is built up using shapes of casting sand. This is all done very cautiously by hand. Very often, various sections of the sculpture are cast and later these sections are welded to each other.
Once the sculpture is cast, the casting sand is knocked out of the sculpture at the bottom side. Therefore, a bronze sculpture is hollow. The sculpture is then polished, it gets a version number and lastly, it is coated with patina. The patina gives it a lovely shine in black, green or brown.