Historic Churches 2021

38 BCD SPECIAL REPORT ON HISTORIC CHURCHES 28 TH ANNUAL EDITION as the church is no longer in regular use, there has been no recent cleaning to the iron transept screens, resulting in a build-up of dust and dirt layers. CLEANING TRIALS After the condition survey of the transept screens and altar rail, proposals were put together for the conservation of this very important ironwork. The main recommendation was to carry out some initial cleaning and conservation trials to find the best cleaning technique, and in addition a trial of suitable materials to use for consolidating the deteriorated paint layers and treating the localised rust patches. A small section to one of the lower screens was selected for the trials. This was initially dry-cleaned with conservation brushes and a vacuum cleaner. The painted surfaces were then wet cleaned with a non-ionic detergent (1% TritonX100) and distilled water (which is pH neutral), applied using cotton wool swabs rolled across the surface. Small rust blisters and areas of loose rust were carefully removed under magnification using a scalpel blade, and brushed with a fine glass bristle brush back to a sound surface. Four potential substances were selected to test which would be the most suitable for consolidating the paint layers and enhancing the overall colour of the paint finishes, which had dulled with age. These were: a five per cent solution of Paraloid B72; a five per cent solution of Paraloid B67 (both acrylic resins in white spirit); Primal WS24; and Lascaux 4176 (both acrylic dispersions in water). Four identical decorative flowers on the lower panel were selected for testing, so the resulting finish could be compared. Two coats of each consolidant were applied, allowing the first to dry before applying the second. A visual assessment suggested that the Paraloid B67 solution in white spirit gave the best result. Following the success of the cleaning and consolidation trials the original paint finish had been significantly enhanced. The client therefore decided to go ahead with the conservation of the transept screens, altar rail and wall lights. The works began in September 2020 during the first lifting of Covid-19 restrictions. CLEANING AND CONSOLIDATION The transept screens were photographed before being dry cleaned with soft brushes and a vacuum cleaner. Attempts were made to wet clean the paint layers and iron, but over larger areas this appeared to be less successful than during the trials. There was also some concern about introducing water to areas of unpainted iron where paint layers had been lost. These generally consisted of tiny rust blisters that had lost their tops. An alternative dry-cleaning technique was tried using Scotchbrite, fine abrasive pads made by 3M that come in a range of grades, the finest being equivalent to fine-grade wire wool. A cleaning routine was developed where three grades of pad were used, firstly very fine, then ultra-fine, and finally finishing with a light cleansing pad. This combination was found to successfully remove the remaining dirt layers and to revive the original paint surface. Small patches of rust were carefully removed using fine brass bristle brushes. Each screen had a number of candle sconces fitted: a row at high level and a row above the choir stalls. These had large accumulations of candle wax remaining in them, which were carefully removed using wooden picks. The same dry-cleaning routine with Scotchbrite pads was applied to the painted altar rails and wall lights. The latter were labelled and removed to a workshop while the electricians completed the fitting of new electric cables. As the decorative detail was much finer on these pieces, the cleaning process was far easier to carry out on a workbench. Once the cleaning works were complete, each screen was cleaned with soft brushes and a hand puffer to remove any remaining dust deposits, while a vacuum cleaner collected the residues. The painted surfaces were then consolidated with two coats of five per cent Paraloid B67 in white spirit applied by brush and left to dry for 24 hours between coats. This helped to fully revive the paint colours, as well as consolidate the surfaces. The screens were then finished with an application of a layer of Renaissance microcrystalline wax, which was buffed up with soft brushes once it had dried. The result is that the original ironwork and its decoration has been protected from further deterioration, and its appearance enhanced so that the original colour scheme can be better appreciated. PETER MEEHAN is an Icon-accredited conservator with over 30 years’ experience in the sector. He specialises in the conservation of heritage metalwork, particularly architectural, engineering and decorative ironwork, and provides advice to those who care for them – see https://hmccuk. wordpress.com/. Labelling on the lower part of a transept screen indicates one of the cleaning and consolidation trials. (All photos: Peter Meehan) A close up of the top of one screen showing the accumulation of dust and dirt A section of an upper transept screen after cleaning and consolidation

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