Taylor Pearce, sculpture conservators and advisers to the Royal Academy, have recently been required to demonstrate the diversity of their conservation techniques in their work on a number of major projects for the Royal Collection, Westminster Cathedral and Westminster Hall.
Most dramatically, the Royal Collection called in Taylor Pearce to salvage a number of marble busts which had been severely damaged in the fire at Windsor Castle in November 1993. Among these was a bust by nineteenth-century sculptor, Nathaniel Theed, of Charles I which had been completely smoke-blackened and had split into three pieces.
Each bust takes about two to three weeks to clean by the use of a micro air-abrasive containing a very fine aluminium oxide powder, according to Keith Taylor, director of Taylor Pearce. This enables the deep carbon deposits to be removed. More persistent stains, however, are drawn out with poultices containing sepialite (magnesium silicate clay) mixed with solvents. Despite these intensive treatments, with such high temperatures deep scorch marks will inevitably still remain in the marble.
In contrast, the work at Westminster Hall (the surviving medieval hall in the parliament complex) was precipitated, not by a sudden cataclysm, but by the gradual erosion of the six fourteenth-century Reigate stone statues of Saxon kings since they were first placed in position in the Hall in 1385. Taylor Pearce has been working on the statues for two years, and finally in December this year they should all be reinstated in their niches at the south end of Westminster Hall.
The greatest enemy to the statues was the early misguided attempt to protect them with coats of limewash, underneath which the Reigate stone was still crumbling away. In addition, the interior iron armatures were corroding. The most problematic part of the project was the removal of these very fragile statues from their niches. They were first faced with ethelene tissue adhered with paralloid resin (soluble in acetone). They were then boxed in with padded braces before transportation to the conservation studio. The principal conservation task was to remove the coats of limewash in a painstaking and labour-intensive operation involving fibreglass brushes and scalpels wielded under magnification. Extra care was necessary to ensure that traces of the original pigmentation were not accidentally removed. Simultaneously, the statues are being consolidated by the injection of acrylics such as paralloid (a reversible substance) and supplementary support fills of stone dust and paralloid.
Finally, Taylor Pearce, in agreement with English Heritage’s sculpture experts, agreed on a deep penetrating overall consolidation with a non-reversible silane resin which should protect the statues from deterioration in their damp environment for the next few hundred years.
Different again is the project to clean the early twentieth-century mosaic decoration by Anning Bell and Gilbert Pownall in Westminster Cathedral. The cleaning of the Lady Chapel involved the removal of waxy candle deposits and took six weeks to complete. Following this, the cleaning of the baldacchino and tympanum are about to be completed as part of a ten-week programme. A simple aqueous solution containing synperonic, de-ionised water and white spirit has been used to remove the grime, and missing tesserae are being replaced from the cathedral’s stock. The cathedral is gradually being restored to its original sparkling condition.
Clearly the work of Taylor Pearce is not atypical of the industry as a whole and sculpture conservation studios are required to work on a diversity of different projects demanding differing treatments and techniques. Along with other conservators, Keith Taylor welcomes the research taking place into new methods of sculpture conservation. In particular, the use of laser technology will herald a new era and will be able to be used on cleaning large-scale works such as large monuments or building frontages as well as detailed cleaning of small sculptures.
Originally appeared in The Art Newspaper as 'Fighting fire and the ravages of time'