BCD 2019

166 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 C AT H E D R A L C O MM U N I C AT I O N S present. Based on this information, a plan for paint removal was prepared using the peel- away system, a thick yogurt-like substance which melts away many layers of paint simultaneously. This system can work well for large volume work, but extreme caution has to be exercised: if left on the columns too long, it would eat into original material and could destroy it completely. (Systems such as peel-away must never be used on more delicate work, like inlaid table tops for example.) Test trials were therefore used to help predict the required dwell times, and progress was monitored constantly. Once sufficiently softened, the paint system was peeled back, drawing the paint layers with it, and a chemical was applied to neutralise any residual alkalis. This chemical was a diluted very mild form of acid, which must be applied to stop the residual and continuous effect of the alkaline poultice removal system. It is harmless to the scagliola matrix, but as a precaution all surfaces were then washed down well with fresh water and the residues sponged off. Areas where the peel-away system had not sufficiently taken off the paint were worked further with a milder liquid paint stripper, which produced good results. The columns and pilasters were then assessed once more, this time in meticulous detail from mobile access towers. Paint removal had revealed a magnificent and rather exceptional yellow jasper scagliola, albeit in need of much further restoration work. Domenico Bartoli had worked extensively in the St James’s area of London and in many other places in England, and he was well known not just for excellent craftsmanship but also for more unusual scagliola finishes. Here his rendition of a yellow jasper lived up to every expectation, but the scagliola had been disfigured by earlier repairs in ordinary non-traditional fillers. Following evaluation, it was determined that there were three stages to the work: making good the areas which had been poorly repaired in the past, making the body of the work smooth again, and polishing it to restore its high gloss sheen. Stage one Without their layers of cream over-paint, the patches of white filler were easily spotted, varying in shape and size from hairline cracks, to one square inch sections, to irregular patches of some 30 square inches in surface area, to corner elements and mouldings missing altogether. These were carefully raked out and keyed to provide a good bonding surface. The top edges of the voids were zig-zagged to provide an irregular line, between the original scagliola and the new mixes (the eye will be deceived more if you marry the old with the new, in an irregular line.) A mixture of PVA and water was then applied to surfaces within the recesses to control suction, ready for the new scagliola mixes to be applied. A small workshop area was assembled on site for preparing the many samples required, as about 24 different colours were recorded on the columns. Furthermore, the columns were complicated in their visual execution. Not only were they extremely rich, but they also had darker coloured banding ascending the columns in a visually pleasing manner. Faithfully replicating all these colours was interesting enough, but applying them in the correct combination to the appropriate area while maintaining the flow of the original was a welcome undertaking, requiring the utmost concentration, care and attention. The areas of void were filled in one at a time, thicker than the main body of work, and when they had acquired a ‘cheesy’ consistency they were carefully cut back to size with a sharp blade . Stage two The stripping process had revealed discoloured and pitted areas, so after the voids had been filled, the surface of all columns and pilasters had to be made smooth again. First, a medium wet-and-dry sandpaper was used with the aid of water from hand-held sprayers. The resulting glut had to be sponged off straight away, to avoid damaging the work as it trickled down the shafts. Where pitted, the surface had to be filled several times with the correct coloured plaster slip and then sanded, using progressively finer grades of sandpaper until a very smooth finish had been achieved ready to take the polish. Stage three This is the most rewarding stage as, after all the hard work and effort, the scagliola finally comes alive in all its glory. Over a period of around three days, a few layers of double boiled linseed oil were applied with soft cloths. Burnishing took place between stages of application with a 1200 grade sandpaper (no water this time) followed by polishing with mechanical buffers, to reveal the rather remarkable yellow jasper scagliola, a result that exceeded all expectations. It is hoped that the above examples have given a brief insight into a range of case studies of scagliola restoration and the craftsmanship involved in this unique historic process. MICHAEL KOUMBOUZIS is a fine art graduate and director of The Scagliola Company (http://scagliolaco.com ). He has been making columns, pedestals, chimneypieces, inlaid tops and restoring period scagliola in fine houses since 1983. The author working on one of the pilasters; compatible scagliola was applied thicker to fill in areas of loss, then cut back when ‘cheesy’. The glory of Bartoli’s work setting off the elegant interior decorative scheme