Preventing the Undesired Surface Veiling after Nanolime Treatments on Wall Paintings: Preliminary Investigations
Metadatos
Mostrar el registro completo del ítemEditorial
MDPI
Materia
Cleaning Consolidation Wall painting Nanolime White glazing
Fecha
2021Referencia bibliográfica
López-Martínez, T.; Otero, J. Preventing the Undesired Surface Veiling after Nanolime Treatments on Wall Paintings: Preliminary Investigations. Coatings 2021, 11, 1083. https://doi.org/10.3390/ coatings11091083
Patrocinador
Ministerio de Ciencia e Innovación, Gobierno de España, with the project PID 2019-105706GB-I00/SRA (State Research Agency/10.13039/501100011033).; Marie Skłodowska-Curie (MSCA-IF) grant agreement No 893762 (NANOMORT)Resumen
During the last decades, the discovery of nanolime and its introduction in the field of
Cultural Heritage has entailed a significant advance for the consolidation of historic wall paintings. Nevertheless, its use is not completely generalized yet within the conservation practitioner’s
community due to its undesired white veiling deposit on the surface after treatment which usually
covers the pictorial layer. Given the scarcity of existing literature which specify how to mitigate this
undesired side-effect, the aim of this work is to carry out the first assessment of possible cleaning
and treatment methods to eliminate those deposits and, at the same time, to analyse their effects
on the consolidation properties. To do that, we have developed laboratory fresco wall paintings
specimens. After applying an artificial ageing cycle to all of them, we consolidated them with CaloSil
IP25, one of the most currently used commercial product in the practice. The elimination of the
whitish deposits has been investigated with different methods: (1) wiping off the superficial excess
of product immediately after each application during the treatment; (2) mechanical cleaning (scalpel)
after consolidation; chemical cleaning with rigid gels of water (3), ethylenediaminetetraacetic acid
(EDTA) (4) and citric acid (5) after consolidation. The effectiveness of each cleaning method has been
assessed by non-destructive methods before and after the consolidation, and repeated after cleaning,
by measuring differences in colour, water absorption by capillarity (i.e., sponge test), superficial
adhesion (i.e., Scotch Tape Test) and by quantifying the thickness of the deposits eliminated by
means of photogrammetry. Results show that both the mechanical cleaning and the removal of the
excess of product after each application during the treatment yielded the most promising results for
conservation practice.