BCD 2019

INTERIORS 5 165 C AT H E D R A L C O MM U N I C AT I O N S T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 1 9 The poor condition of the structure of the columns is evident. The laths had to be strengthened and any delamination injected. The numbering system has to do with the dry assembly of the broken pieces. The pair of verde antique after restoration The thick, white stripper applied on the scagliola and the discoloured, stained surface, after its removal analyses and report, with the aim of restoring the columns to their original beauty. The next step was to carry out a test panel, so a sample area on one of the scagliola pilasters was selected, which measured about 25cm wide and 35cm long. Very briefly, the surface of the existing scagliola was lightly cleaned, sanded and cleaned again. Microcrystalline wax was then applied and the area was carefully polished before awaiting the passage of time to assess. The polishing was a critical aspect of this process as over-polishing would dislodge some of the very soft metal particles thus creating long term problems with moisture penetration. We waited seven whole years as proceedings were delayed, but when we finally visited the music room again in 2008 to assess the sample area, we found that it had endured the test of time extremely well. Our conclusions enabled the subsequent restoration programme to go ahead. CARLTON HOUSE TERRACE A very different set of problems was posed when two full size verde antique columns fell flat on the floor while in storage, smashing to pieces. The first problem was how to make the lath structure of the column strong enough for the loose scagliola pieces to be assembled, while retaining the column’s true axis and original form. The second was selecting a bonding agent for fixing the loose sections to the lath. And finally, how to marry the many different areas, disguising any gaps, voids and sections where the scagliola had fractured beyond repair. After erecting the columns back in their original place, plumbing them carefully to ensure a true axis and entasis, the capitals were reassembled ready for the verde antique restoration. The integrity of the wooden skeleton was ensured by strengthening broken laths by attaching new ones with wood glue, ensuring an excellent bond, and by injecting a slightly diluted PVA-based binder to areas of minute detachment between the lath structure and the plaster backing coat (which is part of the scagliola veneer). The PVA binder is reversible, and had been used before in other projects with excellent results compatible with modern conservation practices. Next, all the broken pieces of scagliola had to be carefully collected and dry-assembled on the lath structure to determine where each one had come from. When this was completed, a plaster slip was used as the bonding agent between the original lath and the broken pieces. For this particular process an agreement with English Heritage was reached and a traditional binder was used – a certain type of plaster of Paris – rather than a modern binding substance, which would have been foreign to the original materials used; again all part of a good conservation strategy. As is usual practice with all scagliola conservation, light cleaning took place as soon as all the pieces had been assembled and secured in place. This was a 1:1 ratio mix of water and isopropyl alcohol, applied with a hand-held sprayer and wiped off straight away with cotton cloths. It was then back to the workshop to replicate the missing scagliola sections and ensure a perfect match where the column surface had smashed to minute, unusable pieces. Some pieces had been kept back for this purpose, as there is no such thing as a standard verde antique finish. All scagliolists have their own unique way of working, so making trial samples is always essential. After reinstating the areas of total loss, followed by the usual cutting back, sanding and filling of the new verde antique mixes and making sure that the adjacent, original scagliola remained intact, the restoration was completed by polishing with linseed oil. The result was a pair of columns in their original place, and even the eye of a connoisseur would not detect any intervention. SPENCER HOUSE In the dining room of Spencer House, four circular columns and four square pilasters had been executed in the 1780s by one of the finest scagliolists in England at that time, Domenico Bartoli. These had since been painted over in a flat cream-coloured paint. The brief was simple: to restore the scagliola work to its original 18th-century opulence and splendour. In accordance with good practice, a visual inspection took place in the preliminary stages, followed by a tactile investigation, tapping on the fabric to locate any delamination or serious defects in the structure of the columns. These two rather low-tech investigation methods can reveal a lot to the experienced scagliola restorer. Historical and photographic archives were then researched to determine the maker, the date of construction and any other important historical information, such as similar examples of the craftsperson’s work and their dates. This research was essential to provide a thorough understanding of the historic and architectural significance of the scheme and to ensure that any replication of missing elements would be based on knowledge, not conjecture. By being fully immersed in the work of the original artist, the scagliolist can ensure that the repairs are recreated in both the correct materials and the style of the original, allowing the new work to be considered as a continuation of the original artist’s own work. Understanding the artist is vital to the success of any restoration project. Photographic documentation of the condition at the start and as work progresses is also extremely important and should be regarded a key part of any comprehensive and complete conservation or restoration package. This will also form future archival information providing a sound source of reference for future interventions. Paint samples were taken to analyse its constitution and the number of layers