Historic Churches 2021

BCD SPECIAL REPORT ON HISTORIC CHURCHES 28 TH ANNUAL EDITION 17 found to be in good overall condition, a testament to the superior quality of the Lincoln Redbed limestone used, combined with a sheltered location and an absence of iconoclasm or heavy-handed restoration. Dirt levels were moderate to light (it is likely they had been scrubbed at least twice during the 20th century) with generally 1–3mm-thick, black sulphation crusts in sheltered areas, crusts of pigeon guano, and tenacious grey dust on the upper surfaces. The condition of the Romanesque frieze, however, was found to be more variable, with some of the panels showing severe structural distress. The frieze was carved from an Ancaster type stone, which is an oöidal limestone. Both Ancaster and Lincoln Redbed limestone are classed as Lincolnshire limestones but they have different visual appearances and qualities. In the mid-20th century Lincoln’s air pollution levels were still high due to local industry and the number of coal-fired power stations in the area. The surface of the frieze was often obscured by heavy black sulphation, up to 6mm thick, that had accumulated since they were cleaned in 1961. Analysis of the dirt’s composition found it to be mainly gypsum (calcium sulphate), calcite and fly-ash particles (a coal combustion product). Oil-based spherical globules and other planar organic growths were also seen under 400x magnification. (Pouli, 2000, pp.63–66). HISTORIC ARCHITECTURAL PAINT It is widely known that the majority of medieval buildings would have appeared quite differently then to how we see them now, and were finished with coatings of limewash or sometimes colourful paintwork (polychromy). Research over the last 30 years has shown us that the West Front of Lincoln Cathedral would have had a rich architectural polychromy, much of which was removed, or covered over with ochre limewash in the 19th and 20th centuries. The remnants of small fragments of historic paint found across the West Front sculptures are precious, and there is a great risk of losing them when cleaning is being undertaken. Before starting our conservation programme, therefore, every care had to be taken to ensure that these remnants were recorded and preserved. Following initial visual examination and recording, detailed investigations on both the Gallery of Kings and the Romanesque frieze included a first phase of polychromy sampling and analysis by wall paintings conservator Eddie Sinclair and paint analyst Catherine Hassall, with a second phase of recording undertaken after cleaning. A combination of careful polychromy mapping by the in-house team, followed by investigation by the paint specialists, provided preliminary documentation for locating and identifying medieval paint during the cleaning process. The exciting results showed that extensive pockets of vibrant polychromy were found to have survived. The phase one survey of the Gallery of Kings identified a distinctive ground layer of red and yellow oxides, with exotic pigments such as azurite and vermillion also found. Phase two polychromy recording of the southern Romanesque frieze panels revealed lead- white ground, red, yellow and ‘golden’ ochre, copper blue/green, vermillion, and azurite, as well as a tantalising glimpse of sophisticated glazes. It was important for the conservators to familiarise themselves with the scheme before they started to clean, as the dirty and degraded nature of much of the paint required great vigilance and sensitivity during the process. 2. 2. Deep redon reverse ofheadandcrown. PossibleGesso Polychromy Green/Blue POLYCHROMY Orange-Red Deep red NOTES. 1.Thedrainagepipeoneither sideof thebaseof theking isbedded inportland cement. N.B -The lapof theking and skyward facing surfaces suchas the small carvings/grotesqueshavea reduced surfacewitha coarse roughened texture (leather likeappearance). -Areasofdeteriora�on,polychromyetc.markedon the schema�care representa�onalandnot to scale.Theyare toolsused to indicate the loca�onandposi�onof thefindings. -Three typesofdirtarepresenton theGalleryofKings.A light superficialdust-like coveringoverallareas.Sulpha�on crustup to3mm thick, located in recessesanda layerofpollu�on/guano that covers the skyward facing surfaces. - In themainhorizontal jointswhere the canopymeets theashlar there is some separa�onbetween the stoneand the roman cementpoin�ng. -Historical losses smaller thanapprox.15mmx15mmhavenotbeenmarked toensure clarityof the schema�c. PRE-CONDITIONRECORD LOCATION: WestFront DATE: January2019 CONSERVATOR: HannahMayhew PaulWoolesACR LINCOLNCATHEDRAL WESTFRONT:GALLERYOF KINGS PRE-CONSERVATION RECORD:KING3 Indent/Replacement Areasof loss 1. 1. Indicative polychromy mapping of ‘King 3’ from the Gallery of Kings, u dertaken before cl aning Cleaning work in progress on the Daniel in the den of lions panel of the Romanesque frieze, with the right-hand side laser-cleaned