‘Waterfall‘ is a sculptural fountain created in 1991 by Antony Donaldson and is located at Tower Bridge Piazza in London.
It is made from cast and fabricated hollow bronze in the form of six nude female figures posed around a central barrel which overflows with water. The centrepiece is situated in a concrete pool with a low surround on which is a seventh figure and several different bronze pieces in the shapes of a watch, harmonic, notebook, pen and a cassette player.
The sculpture had previously been cleaned using an air-abrasion process to remove limescale. Unfortunately, this had left most of the bronze stripped of any natural patina and a substantial amount of the blasting medium had been allowed to remain on the sculpture. The inner bowl had a layer of limestone as well as visible rings of iron corrosion from coins thrown into the fountain.
Treatment: The sculpture was cleaned with the ThermaTech conservation cleaning system to remove loose dirt and pieces of old blasting medium. Water was drained from the upper basic using a wet vacuum cleaner and the excess abrasive sand was removed by hand. Remaining patches of limescale were heated and removed with a brass wire brush.
Tests were carried out using clear and tinted waxes on the remaining patina and attempts were made to replicate the effect of the stripped areas. After experimentation, it was decided that the following process gave the best results. Areas of striped bronze were wetted with water, then a cold patination solution was applied so that it ran down the wet surface creating a natural variation that closely mimicked the natural, rain-washed patina of the intact areas. After rinsing, the bronze was heated and a dilute solution of potassium polysulphide was sprayed on, followed by a repeat of the first patination process. This three-step process created a more natural, varied, and layered patina than could be achieved by a single application.
After patination, the whole sculpture was waxed by heating the surface and applying a lightly pigmented mixture of microcrystalline wax and carnage wax. Tinted waxes in various shades of blue, green, and black were added to create a more natural look and burnt in so they could create a bond with the existing wax layer. Finally, two coats of microcrystalline wax were brushed on the sculpture and allowed to dry completely before buffing.
We also provided detailed recommendations for the appropriate maintenance of the sculpture in the future.