How it’s made

Making a mould
We make moulds from various materials. The first applications are from two-part silicone putty which has minimal shrinkage after it sets and leaves an excellent imprint. We also use polyurethane putty, gelatine and moulding gel for moulds that have a higher melting point. Following the application of a flexible layer, a hard outer layer of plaster or polyester is applied. We store the moulds in a warehouse, except for those made from gelatine and gel as they are not as durable. A mould is an exact record of the artist’s work, which is why it must be handled with care, just like the model itself.
Wax models
Wax models are made by creating hollow wax pieces that are identical to the original model. Wax models also require retouching with modelling tools and fingers to get rid of any imperfections that came about during production. A core made from fireproof mortar made from plaster and chamotte sand is usually poured into the wax model, making it more solid and possible to place on a surface. We make sure it is kept out of any direct sunlight as it can cause melting or deformations.
Gating system
The gating system is set up with the help of tubes that were created by pouring wax into aluminium tools. This also includes the venting of the cores and placing spacers or connectors between the core and the outer material. The gating system has intake pouring ducts (a pouring cup, sprue and runners), as well as vents on the top, or elsewhere if needed. The person who sets these up must have an in-depth understanding of the process as well as be very precise and focused when carrying this out as every little mistake can cause damage. Pouring or plastering with fireproof mortar made from plaster and chamotte sand must be done in specially purposed spaces as, during the process, unwanted plastering of equipment in the workshop can occur.
Plastering
Pouring takes place in a similar way, except that a panel (most often a circular one) is placed around the figure and the suitably thick mortar is poured into this space until it covers the sculpture up to the top of the gating system. Plaster is not aggressive and can be worked with without gloves.
Pouring
Pouring takes place in a similar way, except that a panel (most often a circular one) is placed around the figure and the suitably thick mortar is poured into this space until it covers the sculpture up to the top of the gating system. Plaster is not aggressive and can be worked with without gloves.
Drying the forms
The plaster figures are called forms. These are then loaded into a kiln. A kiln is a space in which temperatures can reach 700°C. The forms are dried here for as long as necessary until they are completely dry and do not contain any wax or water.
Casting bronze
The forms cannot withstand bronze being simply poured into them, that is why we place them into frames and press moulding sand around them to hold them together. The forms are covered to stop sand from getting into the holes where the bronze is poured into. We pour the bronze just by eye, which is why our many years of experience, as well as a great deal of expertise, are needed. The bronze is melted in furnaces with a crucible. The crucible is made from graphite. There are many types of bronze; from red and soft bronzes to yellow and hard ones. We usually pour silicone bronze which is used in the majority of foundries in the United States. This bronze is very malleable, suitable for working with, and can be welded without leaving any trace.
Cleaning
Cleaning the cores from the inside of the statue is done using a drill, special cleaning tools and small hammers which are used to create vibrations and the free-flowing sand drains out of the sculpture. Larger statues are cleaned in a similar way but using larger tools. We don’t hit the surface of the models, but choose areas on the ducts or elsewhere where no damage can be done.
Treating the bronze cast
After cleaning the bronze cast comes the processing of the bronze cast. We use an angle grinder to cut away the gating system, being very careful and exact so as not to damage the sculpture. Then we use a lot of different foundry tools to remove various deformities that came about during the bronze casting. When we remove all the imperfections, all that is left are the little holes left by the spacers that hold the core in the form. The holes are carefully and precisely welded, and the welds are then treated so that no trace remains. A inox crosspiece is welded onto the bottom of the sculpture and in which we cut a thread which serves as a mount for the final fixing of the statue to it’s base.
Sanding
When the bronze cast is completely treated and has no more deformities, it is sanded with a sanding machine which levels out and cleans the surface of the statue and prepares it for patinating. After sanding, any deformities on the figure become more visible. At this point we carefully inspect the figure and fix any imperfections.
Patination
This is the last part of the process and where the statue reaches it’s final form. The sanded statue is placed on a base made from grog and heated with a burner. We only heat it up to a certain temperature and then apply various chemicals that oxidise in various ways on the bronze. When the desired patina is attained, the statue is coated with a microcrystalline wax which protects the statue from weathering.