{"title":"Initial investigation into the effect of varying parameters in using an Er:YAG laser for the removal of brass-based overpaint from an oil-gilded frame","authors":"Pawita Boonrat, M. Dickinson, M. Cooper","doi":"10.1080/19455224.2019.1706592","DOIUrl":"https://doi.org/10.1080/19455224.2019.1706592","url":null,"abstract":"Abstract The removal of brass-based overpaint, applied during previous restoration, from an oil-gilded frame by the application of solvents can be challenging and difficult to control due to the often similar solubilities of the paint and oil gilding. In this study, Er:YAG laser radiation (2940nm) has been used to remove brass-based overpaint from a discoloured overpainted oil-gilded frame. Tests have been systematically carried out to investigate the effect of changes to: (1) laser parameters (fluence; number of pulses; pulse duration; repetition rate), and (2) choice of pre-wetting agent (water; isopropyl alcohol; acetone) on the removal process. Observations of the irradiated surfaces revealed that the thermal interaction between laser radiation and the overpaint led to decomposition of the overpaint binder which weakened the paint sufficiently to enable removal using a cotton swab. By using acetone as a pre-wetting agent, the overpaint was removed from a small area of the frame by 20 pulses at 0.8J/cm2 (80µs pulse duration; 1Hz) revealing the gold leaf. This investigation demonstrates the potential for Er:YAG laser radiation in the controlled removal of brass-based overpaint from gilded wood and the requirement for further work to optimise the removal process and characterise the ‘cleaned’ surface.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"106 - 94"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1706592","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41507931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The removal of bronze paint repairs from overgilded picture frames using an Erbium:YAG laser","authors":"Gerry Alabone, M. Carvajal","doi":"10.1080/19455224.2019.1706595","DOIUrl":"https://doi.org/10.1080/19455224.2019.1706595","url":null,"abstract":"Abstract The removal of old repairs made using metal flake paint, commonly referred to as bronze paint, has often been difficult to achieve from gilded wood and especially from oil gilded surfaces with similar solubility parameters. Conservators at the National Trust's Knole Conservation Studio in the UK treated gilded picture frames from the Knole House collection using an energy-attenuated Fotona (Dualis XS) Erbium:YAG laser, with fluencies between 0.5 and 1.0J/cm2, pre-wetted with hydroxyl and non-hydroxyl group-containing solvents. Comparisons of the effects of cleaning using only solvents and with the laser were made, and cross-sectional and media composition analysis carried out using optical microscopy, scanning electron microscopy with energy dispersive X-ray (SEM-EDX), Raman and Fourier transform infrared (FTIR) spectroscopies.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"107 - 121"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1706595","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49123897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Preliminary study into the reduction and removal of naturally aged varnishes from painted surfaces using an Er:YAG laser in a two-step cleaning process with solvents","authors":"R. Hellen","doi":"10.1080/19455224.2019.1706594","DOIUrl":"https://doi.org/10.1080/19455224.2019.1706594","url":null,"abstract":"Abstract A preliminary study into the reduction and removal of naturally aged varnishes, aimed at collating observations to encourage further study of the cleaning of paintings with intractable, difficult to remove coatings, is presented in this article. Er:YAG laser cleaning trials with dry laser exposures followed by solvent removal of natural resin varnishes were conducted on a naturally aged test panel, and an expendable nineteenth-century oil painting. Surfaces were examined with normal and ultraviolet light, a headband magnifier, and low-power digital microscopy, videography and colorimetry. Standard solvent cleaning tests were first carried out, followed by a two-step cleaning protocol where Er:YAG irradiation of the coating was followed by solvent cleaning, the laser being used to promote a weakening or disaggregation of the topmost portion of the layer or layers of varnish. The aim was to assess the laser cleaning outcomes conservators might expect on ‘real’ as well as mocked-up surfaces; results are presented from one of each. Cleaned areas of paint were also directly exposed to Er:YAG irradiation to determine a safe fluence with observations limited to relatively low magnifications. Overall these efforts inform the risks and contribute to the development and the safe use of this novel cleaning method.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"79 - 93"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1706594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48176908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Er:YAG laser cleaning of ‘San Marziale in Gloria’ by Jacopo Tintoretto in the Church of San Marziale, Venice","authors":"A. Brunetto, G. Bono, Fabio Frezzato","doi":"10.1080/19455224.2019.1706596","DOIUrl":"https://doi.org/10.1080/19455224.2019.1706596","url":null,"abstract":"Abstract This article presents a parameter optimisation study for the use of an Er:YAG laser in combination with different solvent mixes for the cleaning of a large oil painting on canvas by Jacopo Tintoretto. The painting underwent restoration work between the 1700s and the mid-1900s in which it was lined and some areas were coated with a pigmented protective varnish, which has oxidised over time and has completely obscured the work. Analysis was undertaken in order to study the condition of the work, the painting technique used, and to monitor and verify the effectiveness of the cleaning treatments considered to remove the oxidised varnish. The article reports how the careful calibration and use of cleaning techniques involving the Er:YAG laser and solvent mixes have led to a full recovery of the vibrant chromatic intensity to the pictorial surface of the work.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"44 - 58"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1706596","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46323107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Er:YAG lasers in conservation","authors":"J. Kemp","doi":"10.1080/19455224.2020.1720393","DOIUrl":"https://doi.org/10.1080/19455224.2020.1720393","url":null,"abstract":"","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"1 - 1"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2020.1720393","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45344186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A study on the heat distribution and oxidative modification of aged dammar films upon Er:YAG laser irradiation","authors":"C. Chillè, F. Sala, Qiang Wu, C. Theodorakopoulos","doi":"10.1080/19455224.2019.1707699","DOIUrl":"https://doi.org/10.1080/19455224.2019.1707699","url":null,"abstract":"Abstract This work shows the impact of one Er:YAG laser pulse to both the surface and bulk of aged dammar varnishes. Tests were performed in fluences ranging from 0.56 to 2.4J/cm2 and pulse durations of 100 and 300μs. Temperature changes upon irradiation were examined by (a) live recordings with an infrared thermal camera, and (b) determining the optical properties of the varnish, which allowed for estimates of the linear absorption coefficient and the temperature rise associated with the laser irradiation. Transmission and Fourier Transform Infrared (FTIR) spectroscopy studies captured increased energy transmissions through varnish films, as well as registering a reduction of hydroxides and carbon–hydrogen bonding as a function of fluence, respectively. FTIR and Differential Scanning Calorimetry (DSC) experimentally determined the absorption coefficient and the specific heat capacity of dammar films, and an overview of laser spots was carried out with Scanning Electron Microscopy (SEM). Evidence on the varnish response to Er:YAG laser irradiation is provided.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"59 - 78"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1707699","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41917497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Er:YAG laser cleaning of a marble Roman urn","authors":"A. Andreotti, M. Colombini, A. de Cruz","doi":"10.1080/19455224.2019.1706593","DOIUrl":"https://doi.org/10.1080/19455224.2019.1706593","url":null,"abstract":"Abstract There are very few documented instances of the use of an Er:YAG laser in the cleaning of stone artefacts; however, the cases reported in the literature have shown its effectiveness in the removal of surface organic patinas and lichens. A Roman marble funerary urn (67–100 AD) of archaeological importance was covered with an intractable surface layer that obscured its delicate decorative carving. Chromatographic mass spectrometric and Raman spectroscopic techniques allowed the characterisation of those inorganic and organic materials that had undergone photo-oxidation and biological changes, resulting in the thick encrustation. An Er:YAG laser at 2940nm, with a pulse length of 300µsec, was used for cleaning the urn. Preliminary tests were performed with fluences ranging from 0.7 to 6.4J/cm2 and in the presence of a variety of wetting agents. The laser cleaning resulted in a sufficiently clean marble surface with the thick deposit of unwanted material removed. Finally, the sensitivity of the method allowed for a compact layer of calcium oxalate to be retained on the marble’s surface to help protect it.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"12 - 24"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1706593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43796045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Introduction: Er:YAG lasers in the conservation of artworks","authors":"E. Teppo","doi":"10.1080/19455224.2019.1706597","DOIUrl":"https://doi.org/10.1080/19455224.2019.1706597","url":null,"abstract":"Abstract This article highlights the uniqueness and potential of the long pulse Er:YAG laser in the conservation of artworks. Laser sources and operating parameters are summarised in terms of controlling, optimising and confining a material's near-surface interaction with laser irradiation. When present, O–H bonds in materials are very strongly absorbing at 2940nm, the emission wavelength of the Er:YAG laser, and the thermal diffusion depth during the laser pulse is often shallow and underlying material is little affected. Laser exposure can therefore produce beneficial thermally-induced photo-disruption at the surfaces of media that contain O–H bonds, such as aged natural resin varnishes, biological growth and adhesives. If an unwanted superficial layer lacks sufficient O–H content, it can be pre-wetted with solvent to increase absorption of the laser radiation. Laser exposure of unwanted surface material is described in conjunction with conventional methods of solvent cleaning and parameters for reducing the risk of alteration and solubilisation of underlying materials are given. A synopsis of each of the research articles included in this special issue of the Journal concludes this contribution.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"43 1","pages":"11 - 2"},"PeriodicalIF":0.8,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1706597","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46963801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigating the condition of iron gall ink drawings: developing an assessment survey","authors":"J. Kosek, C. Barry","doi":"10.1080/19455224.2019.1656660","DOIUrl":"https://doi.org/10.1080/19455224.2019.1656660","url":null,"abstract":"Abstract It is well established that iron gall ink causes deterioration and embrittlement of paper in the presence of one or more risk factors, such as unstable ink components, high humidity and unsafe handling, with the ink changing colour from black to shades of brown. As iron gall ink has been the prevailing drawing medium in the West from medieval times to the eighteenth century, with its use declining into the twentieth century, monitoring the condition of iron gall ink drawings is of great concern to all custodians of graphic art collections. Selected iron gall ink drawings have been examined using visual methods in the British Museum Prints and Drawing collection to identify, assess and describe condition issues specific to the medium. This has led to the production of a reference catalogue of damage, which has underpinned this draft-design for a condition survey tool. This survey has then been developed with input from conservators at the Albertina, Vienna, Kupferstichkabinett Staatliche Museum zu Berlin, Musée du Louvre, Paris, Rijksmuseum, Amsterdam and the Statens Museum for Kunst, Copenhagen, based on the material from their collections. This article presents the pilot project used to test the survey alongside its initial validation and outcomes.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"42 1","pages":"191 - 209"},"PeriodicalIF":0.8,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1656660","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42138805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The restoration of two historic leather bindings according to a new strategy","authors":"Rushdya Rabee Ali Hassan","doi":"10.1080/19455224.2019.1654532","DOIUrl":"https://doi.org/10.1080/19455224.2019.1654532","url":null,"abstract":"Abstract The current research presents a new strategy for the treatment of degraded historical leather. Digital microscope, pH, FTIR and SEM analyses were used to evaluate the degradation of two leather bookbindings dated back to the fourteenth century. A conservation process was executed and included cleaning and the filling of holes according to a new recipe in the field of leather conservation containing leather powder, anhydrous cellulose, cellulose powder, acacia arabica, gelatin powder and clay nanoparticles. The new recipe was evaluated on modern leather samples before and after their accelerated ageing by monitoring any changes in their pH and colour, along with differential thermal analysis before the filler was applied to the historic leather. Results showed that the acidity of the leather remained in its natural state and the leather did not exhibit any oxidation nor hydrolysis. Moreover, the evaluation process for the new recipe suggested that it could be a promising material for the filling of losses to leather especially as it is thermally stable and shows consistency with the acidity of leather. Furthermore, the new fill material is easy to manipulate and shows no significant shrinkage or change to its colour.","PeriodicalId":43004,"journal":{"name":"Journal of the Institute of Conservation","volume":"42 1","pages":"210 - 225"},"PeriodicalIF":0.8,"publicationDate":"2019-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/19455224.2019.1654532","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48155317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}