BCD 2019

INTERIORS 5 157 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 substantial number of Cordelova panels (each measuring 30 by 24 inches) attached to one of the ceilings. Unfortunately, the lath and plaster ceiling is in a poor state with approximately half its surface area fallen away, exposing some of the floor joists in the room above. The surviving plaster and panels will be retained, consolidated and further secured, with new plaster reinstated to provide seamless repairs to the original material. Approximately 70 new substitute panels will be reproduced, using materials compatible with the original composition and in line with best conservation practice. Traditionally, the reproduction of a three-dimensional surface such as this would be achieved by using a suitable moulding material and producing a cast, potentially from fibreglass or other similar material from the mould. However, the surface of the panels was covered in a thick layer of peeling and crazed paint. Any resultant mould taken would have lacked crisp definition and included all the surface blemishes that had developed over time. It was therefore decided that the creation of a mould using a contactless method was far more appropriate, minimising the risk to the existing panels and allowing the resultant digital file to be cleaned using computer software to remove all imperfections. A single panel in good condition was selected and scanned using an Artec Eva 3D white-light scanner, with 3D point accuracy of up to 0.1mm. This created a polygon mesh from the point cloud data, representing the geometry that was in the line of sight of the scanner. The polygon mesh then embedded a colour signal that created a three-dimensional full- colour representation of the scanned object. The resulting file was then exported to two different CAD packages which helped recreate a precise geometry suitable for export to a computer-controlled flatbed router. The router was then used to create a positive pattern, faithfully reproducing the contours and dimensions of the original panel. With the positive mould created, a corresponding mould was cast in flexible addition cure silicon rubber and utilised as the master mould to create the required number of new panels. Following exhaustive trials to finalise the materials required to produce a robust, flat and aesthetically suitable panel, brown unglazed parcel paper and D4 waterproof PVA adhesive were used to create the embossed paper design. The raised relief was further strengthened with Jesmonite AC100, an acrylic polymer and mineral resin, to stiffen and add robustness to the raised design. Further Information D Gonzalez, C Cogdell, ‘The raw materials of the linoleum life cycle’, Design Life-cycle, 2014 (www.designlife-cycle.com/linoleum/) Lincrusta, ‘History’, Lincrusta: the ultimate wallcovering since 1877, (https://lincrusta. com/our-history/) Brazil, H, Lincrusta 1877–1887: The Development, Designs and Character of Lincrusta-Walton . MA in Conservation by Research (unpublished). University of Lincoln, 2018 A V Sugden, J L Edmondson, A History of English Wallpaper 1509–1914, London: Batsford Ltd, 1924 P H Simpson, Perspectives in Vernacular Architecture, vol.7, Exploring Everyday Landscapes, Linoleum and Lincrusta: The Democratic Coverings for floors and walls , Vernacular Architecture Forum, 1997 T C Jester, Twentieth Century Building Materials: History and Conservation , Getty Conservation Institute, US, 2014 C Oman, J Hamilton, Wallpapers A History and Illustrated Catalogue of the Collection in the Victoria and Albert Museum , Sotheby Publications, 1982 L Hoskins, The Papered Wall History, Pattern, Technique , Thames & Hudson Ltd, 1994 AUTHORS HELENA BRAZIL is currently completing her MRes on Lincrusta-Walton at the University of Lincoln. PAUL CROFT is a conservator with Lincoln Conservation (see page 154) and research fellow at the University of Lincoln. A section of original Cordelova before restoration A new painted panel on plasterboard The new mould prepared with a computer-controlled flatbed router from 3D scans The damaged Cordelova ceiling at the Crescent, Buxton (All photos: Lincoln Conservation) Originally designed by architect John Carr and built in 1780, this Grade I listed building later became a hotel, assembly room and five lodging houses before being converted for use by the local authority in the 1970s. It is currently undergoing a major programme of restoration, due for completion in 2019, funded in partnership by the Heritage Lottery Fund, Buxton Crescent & Thermal Spa Co Ltd, the local authority and Historic England. The work includes the replication of a