The cost of creating a bronze sculpture using the traditional lost wax casting process reflects far more than the value of the bronze itself
From the artist’s creativity in sculpting the original model and producing the wax replica, to the specialist knowledge required to cast the bronze successfully and the skilled craftsmanship needed to apply the final patina, each stage demands experience, precision and time
Because much of the process is done by hand, each bronze is unique. No two castings are ever completely identical, even when produced from the same original mould. These subtle variations are a hallmark of authentic bronze sculpture, reflecting the artistry and craftsmanship invested in every piece
Creating a realistic and finely detailed bronze sculpture begins long before the first piece of clay or wax is shaped. It starts with careful research and the collection of reference material, ensuring the artist fully understands the subject from every possible angle
Particular attention is given to photographs that capture the expression, character and personality the artist and commissioner wish to preserve in the finished sculpture. It is often these subtle details that transform a good likeness into a truly memorable portrait
By carefully studying and selecting the most appropriate reference images, the artist can create a sculpture that is both lifelike and meaningful, faithfully capturing not only the subject’s appearance but also their individual character
Where appropriate, we use modern digital technologies to improve the accuracy of portrait commissions, while ensuring the traditional hand-crafted lost wax casting process remains unchanged
With the research complete, the artist begins creating the original model. Depending on the project and the preferred working method, this may be sculpted in modelling wax, clay or other oil-based materials that remain soft and workable throughout the creative process
At Escar UK Bronze, we generally favour modelling wax because of its exceptional versatility. Unlike clay, it does not usually require an internal armature (a supporting framework), allowing the artist to concentrate on developing the form rather than constructing additional support
By blending different grades of modelling wax and specialist additives, the material can be tailored to suit the needs of each project. Its hardness, flexibility and working characteristics can all be adjusted, giving the artist complete control throughout the sculpting process
One of modelling wax’s greatest advantages is its sensitivity to temperature. When cool, it becomes firm enough for carving crisp details. As it warms, it softens into a pliable material that can be shaped, modelled and refined with ease. It can even be heated until liquid and applied with a brush to build delicate layers, or allowed to cool slightly before being applied with a spatula or sculpting knife where greater thickness is required
Once cooled, modelling wax is capable of capturing an extraordinary level of fine detail, making it particularly well suited to portraiture and intricate sculpture
Unlike clay, modelling wax does not dry out, allowing work to be paused and resumed without affecting the model. This is especially valuable for commissioned sculptures, where adjustments or client feedback may be incorporated over an extended period
Another important benefit is that modelling wax can be reused many times. Material removed during sculpting can be remelted and recycled, making it both economical and ideal for refining a design until the artist is completely satisfied
Finally, modelling wax offers complete flexibility throughout the creative process, allowing material to be added, removed or reshaped with ease as the sculpture evolves
Once the original wax model has been completed, a two-part mould is created to capture every detail of the sculpture. The mould consists of an inner flexible layer and a rigid outer support shell, allowing it to be removed and reassembled with complete accuracy
The inner mould is typically formed by carefully applying successive layers of latex or silicone over the wax model until the required thickness is achieved. This flexible layer faithfully reproduces every texture, contour and fine detail created by the artist before being left to cure
To protect and support the flexible inner mould, a rigid outer shell—commonly made from plaster or fibreglass—is then constructed around it
During this stage, locating flanges incorporating interlocking register pegs are formed around the mould. These ensure the two halves separate cleanly once cured and, more importantly, fit back together in exactly the same position every time they are reassembled
Where necessary, bolt holes are incorporated into the flanges to secure the mould halves firmly together, preventing even the slightest movement during subsequent stages of the casting process
Once fully cured, the mould is carefully opened and removed from the original wax model, preserving every detail ready for the next stage of production
Over time, and after repeated use, even the highest quality moulds will gradually lose some definition. In addition, flexible silicone components can occasionally suffer minor damage due to their delicate nature
For this reason, mould condition is carefully monitored throughout the production process to ensure every wax positive remains faithful to the original sculpture in both detail and quality
If any degradation is detected, the existing wax model is returned to the artist for refinement where necessary. A new mould is then created from the updated model, ensuring the integrity and detail of the edition is fully maintained. The previous mould is then retired
The two halves of the mould are carefully reassembled and secured before molten modelling wax is introduced into the cavity. For smaller sculptures, the mould is gently rotated so the liquid wax coats the entire inner surface, creating an even layer of the desired thickness
Every artist develops their own preferred techniques and uses carefully judged quantities of wax to achieve the ideal wall thickness for each sculpture
For larger sculptures, where rotating the mould is impractical, the wax is usually applied by hand in successive layers until the required thickness—typically around 3 mm—is achieved
Once the wax has cooled and hardened, either naturally or by force cooling smaller moulds with water, a hollow wax positive is produced. This is a faithful replica of the original model and will eventually become the bronze sculpture
The flexible mould is then carefully removed from the wax positive. Where multiple castings are required, the mould can be reused repeatedly to produce identical wax positives for each edition
Once an edition has been completed, the mould is carefully cleaned, inspected and stored, allowing further castings to be produced in the future if required
Before the casting process continues, the wax positive is inspected and, where necessary, carefully chased to remove any minor imperfections
Chasing is a traditional finishing technique in which heated metal tools are used to smooth the wax surface, refine fine details and eliminate the faint seam line created where the two halves of the mould meet. This ensures the wax positive faithfully reflects the artist’s original work before progressing to the next stage of the lost wax casting process
For smaller sculptures, the hollow wax positive is placed upside down in a bed of sand, which supports it securely while the internal core is formed.
A ceramic slurry is prepared by mixing a specialist refractory powder with water. A proportion of sand is then added to increase its strength before the mixture is poured into the hollow wax positive
Once the slurry has set, the wax positive is removed from the sand and now forms the inner half of the mould
For larger sculptures, an additional stage known as spruing is carried out before the ceramic core is created
Solid wax rods, known as sprues, are attached to the outside of the wax positive to form a network of channels. During the casting process, these channels serve two essential purposes
When the mould is heated, the molten wax drains away through the sprues, leaving a series of hollow passages within the ceramic shell. Later, when molten bronze is poured into the mould, these same passages allow air and gases to escape while guiding the bronze into every part of the sculpture, helping to ensure a complete and successful casting
Once the wax positive has been sprued, it is coated with successive layers of ceramic slurry and fine refractory sand, both inside and out. This process follows the same principles used for smaller castings but is adapted to accommodate the greater size and complexity of larger sculptures
Where a sculpture is particularly large or has a long, narrow form, the outer ceramic shell is allowed to cure before the mould is separated into two halves. The inner surfaces are then coated individually before the sections are reassembled. These become the inner and outer ceramic shell moulds
Additional layers of ceramic slurry and refractory sand are applied until a shell approximately 12 mm (½ inch) thick has been built up. The shell is then reinforced with wire and further ceramic layers to provide the strength needed to withstand the casting process
Depending on the design of the sculpture, the ceramic shell may remain as a single assembly or be divided into separate sections. Larger or more complex sculptures are often cast in individual pieces before being expertly welded together during the finishing stage
Once the ceramic shell has fully hardened, metal locating pins are driven through the outer shell, across the wax layer and into the inner ceramic core. These pins ensure the inner core remains perfectly aligned after the wax has been melted away, maintaining a consistent wall thickness throughout the finished bronze casting
Before the ceramic mould is ready to receive the molten bronze, it is thoroughly inspected to ensure it is structurally sound and free from defects.
Any weak areas or minor damage are carefully repaired, while unwanted openings are sealed to prevent leaks during casting. Where necessary, additional openings may also be incorporated to assist with wax removal during the firing process
For larger castings, strategically positioned openings are formed around the base of the mould and temporarily sealed with wax plugs. During the burnout stage, these plugs melt away, providing controlled drainage paths for the molten wax while helping to prepare the mould for the bronze pour
Once the ceramic mould has been completed, it is carefully positioned before large, slow-burning logs are arranged beneath and around it
A temporary kiln is then constructed around the mould using breeze blocks, with a metal roof fitted above to retain the heat. Kindling is placed between the logs and the kiln walls before the fire is lit and carefully tended as the temperature gradually increases
The logs are left to burn slowly overnight, allowing the ceramic mould to heat evenly. This gradual heating is essential, helping to prevent the mould from cracking when the molten bronze, at approximately 1,200°C, is poured the following day
It is this stage that gives the process its name — the Lost Wax Bronze Casting Process
While the ceramic mould is being prepared, the bronze ingots are melted in a separate furnace ready for casting
The furnace is traditionally fuelled with wood, while a forced-air blower supplies additional oxygen to intensify the fire and raise the temperature to approximately 1,200°C. At this temperature, the bronze becomes fully molten and is ready to be carefully poured into the prepared mould
With the ceramic mould fully prepared and the bronze heated to its molten state, the casting process can begin
The molten bronze is carefully transferred from the furnace in a crucible before being steadily poured into the prepared openings at the top of the mould. As the bronze flows through the internal channels, it fills every part of the cavity left behind by the lost wax process
Once the mould has been completely filled, the bronze is left to cool and solidify under carefully controlled conditions. This gradual cooling helps the casting retain its precise shape, structural integrity and fine surface detail
The bronze pour is one of the most critical stages of the entire process, where careful temperature control, timing and experience combine to produce a high-quality bronze casting ready for the finishing stages
Once the bronze has cooled sufficiently, the ceramic mould is carefully broken away to reveal the casting within. The inner ceramic core is drilled out, the outer shell is broken away with hammers, and the bronze sprues are cut from the sculpture
The sprues, now cast in bronze, are cut off to be melted down and recycled for future castings. The ceramic inner core and outer shell, however, have fulfilled their purpose and are destroyed during this stage
The bronze casting has now emerged from the mould, but it is still far from the finished sculpture. Before patination can begin, the casting undergoes an extensive process of cleaning, refining and finishing
Generally, the larger the casting, the more finishing work is required. Any remaining traces of the casting process must be carefully removed before the bronze is ready for its final surface finish
This stage, commonly known as metal chasing or fettling, involves using grinders and other specialist tools to remove the bronze sprues, eliminate casting seams and dress the surface until the sculpture faithfully reflects the artist’s original work
Any imperfections are then corrected. Excess bronze is ground away, small casting defects or surface pits are repaired, and areas where the bronze has not cast perfectly are rebuilt by welding before being carefully re-shaped and blended into the surrounding surface
Where a sculpture has been cast in several sections, these components are expertly welded together and the joints meticulously dressed until they become virtually invisible
Finally, the finest details are restored or enhanced using precision grinders and rotary tools fitted with a variety of specialist burrs. Fur, feathers, hair, skin texture and other intricate features are refined by hand, bringing the sculpture to life before the final patination is applied
With all the finishing work complete, the bronze is ready for the final stage of its transformation—patination. Carefully selected chemical solutions are applied to the heated bronze to create the desired colour and tonal effects
Once the desired patina has been achieved, the surface is protected with successive coats of specialist wax. The first coats are applied while the bronze is still warm to ensure deep penetration, followed by additional cold applications. The sculpture is then carefully buffed to produce a rich, enduring lustre while providing long-lasting protection for the bronze
As outlined in the narrative above, the art of bronze casting is a time-honoured, hands-on process that passes through many carefully controlled stages before a finished sculpture is ready for delivery
We hope this insight has been informative and has helped illustrate the level of skill, craftsmanship and attention to detail involved in producing a traditional lost wax bronze casting
Every bronze sculpture is therefore far more than a cast metal object; it is the culmination of artistic vision, traditional craftsmanship and countless hours of skilled hand work