ブックタイトルConservation and Restoration of Western Paper

概要

Conservation and Restoration of Western Paper

abcPhoto 30a,b Cleaning the map with thin cast of gellan gumPhoto 30c Detail of map during cleaningwith gellan gumPhotos 30a-c Relief Map of Canada, Atlas School Supply Co., Chicago, 1909, 80.0 x 114.0 cm., Library and ArchivesCanada R14016 vol. 2Photo 31a Stain reduction using gellan gum andBorane reductive bleachPhoto 31b Comparison of map sections: left, beforestain reduction, right, after treatment withgellan gum and borane reductive bleachPhotos 31 Sarony, Major and Knapp, Lithographers, City of Ottawa, Canada West, 1858-61, lithograph on wove paper, 74.2x 99.7 cm, Library and Archives Canada, R3133-3997894prepared with RO water was used to cleana severely discoloured relief school map bypressing it into contact with the irregularsurface (Photos 30a-c). To discouragetidelines, gel applications were overlapped ascleaning progressed.5-5. REDUCTIVE BLEACHING WITHGELLAN GUMTo expand the range of stain reductiontreatments, reductive bleaching solutions canbe incorporated into gellan gum gel. Borane,a tert butylamine complex ((CH 3 ) 3 CNH 2 .BH 3 ) (7g/L) is added to a calcium acetatesolution (0.4g/L) after the gellan gum isadded and the colloidal suspension is heatedin the microwave. Note that proper personalprotective equipment must be used whenhandling borane tert-butylamine complex,including appropriate gloves, goggles andrespirators. Preparation of the solution andtreatment should take place under adequateextraction, and the gel must be disposed ofas hazardous waste.A severely deteriorated lithograph ofa bird’s eye view of Ottawa underwentextensive treatment. After backing removal,bathing and light bleaching, a 2% reductivebleaching gel was prepared in calciumacetate solution, to which 7g/L of borane77