The art of lost wax casting

Part 2

The negative moulds made on the sculptures to be cast in bronze are used to obtain a positive wax of the sculpture itself, of the same thickness that the bronze should have.

The wax thus obtained is retouched, i.e. any imperfections are removed,

until it is perfect and ready to be incorporated into a three-dimensional network of castings,

and then covered with a refractory material called “loto”.

The “loto” mould containing the wax is cooked in the furnace for several days

Cooking melts and burns the wax contained in the “loto” moulds, leaving the empty cavity with the shape of the burnt wax inside.
After cooking, the “loto” moulds are placed in a hole in the ground.

We now proceed to the melting of bronze alloy,

And to the casting of the molten bronze into the “loto” moulds;

Bronze thus takes the place of wax; the moulds are broken to extract the bronze castings

The castings are freed from the castings and sandblasted to clean them from the “loto” leftovers.

The castings are now cleaned and chiseled,

e successivamente rimontate a freddo e poi saldate.

The last phase is the patination of the sculpture: it involves oxidizing the surface of the bronze in the same way that the atmosphere would, over the years, but much more quickly

The lost wax casting technique has remained the same for centuries. Today, of course, methane is used instead of coal for the melting furnaces and for the furnaces for cooking “loto” moulds, electric tools such as hoists, cranes, forklifts, etc. that allow the handling of heavy parts, once done completely by hand.
The only changes related to the materials were the replacement of organic gelatin to make the negative moulds with silicone rubber, and the replacement of beeswax, now very expensive, with paraffin.
Even bronze welding is no longer oxyacetylene flame but takes place with electric welders in an argon atmosphere.


Las Vegas, the Bellagio Hotel

The furnishing of gardens, parks, interiors of villas and hotels is one of the frequent works of the Galleria Bazzanti. Our architects design the furniture on customer request, or collaborate with the architect that the customer already has. A typical case is that of the Bellagio Hotel in Las Vegas, where the Galleria Bazzanti collaborated with architect Roger Thomas on the design and construction of the hotel gardens, building a series of stone and marble furniture accessories. The architect made requests for accessories, leaving to the Galleria Bazzanti the choice of models and sculptural parts. Preparatory drawings have been made to show the architect that, after approval, have been used for the realization of the works: different models of vases, containers, obelisks, etc.

the large fountain with insertions of green marble for one of the pools

yellow Siena marble vases

and other architectural furnishings.

One of the materials that the architect has chosen is “Pietra Leccese” which is extracted in the quarries of the Salento region, in the south of Italy. The characteristic of this stone is that it is not too hard when it is extracted from the quarry and is therefore more easily sculpted than marble. But it has the property of becoming harder and harder over time due to a chemical reaction with the gases of the atmosphere.
It is the material that has been used since the Renaissance for fountains and garden accessories, but especially for the famous Baroque facades of Apulian churches.
The construction of the large stone fountain was particularly delicate. Given the size and transport problems, we had to create it in four slices assembled on site. In some fountains inserts of green marble have been applied.
Another material desired by the architect is the yellow Siena marble, with a typical amber yellow color, extracted from the Montagnola Senese quarries, in the municipality of Sovicille, also used in antiquity. It lends itself very well to being worked and turned for architectural furnishings.