Conservation of urban art
: coatings and green cleaning methods for vandalized urban art murals in Italy and Portugal

  • Margarida Santos Jesus de Castro (Student)

Student thesis: Master's Thesis


This research focuses on methodologies for intervention in urban art murals made with aerosol paints. The dissertation is divided into two blocks of research that complement each other based on the YOCOCU’s mural art conservation experience. The first block reports the research on protective coatings, in order to prevent the action of vandalism in aerosol inks, such as the accelerated deterioration of the original constituents in a mural work. Coatings selected for tests were those usually used for built heritage and considered anti-graffiti. To evaluate the performance of these coatings on various paints, analytical tests such as OM, SEM/EDS and colorimetric analyses have been performed. SEM/EDS and OM results showed that vandalized inks with coatings didn’t penetrate into the chromatic layers or were altered with the vandalism simulation. Colorimetric valuesregistration in paints with coatings over four months however shows alterations in all of the selected paints. The second block focuses on solutions for cleaning murals that have been subjected to vandalism. A green methodology was tested where combinations of solvents of low toxicity were chosen. These were selected under the criteria of being not harmful to the artwork, the operator and the environment. The mixtures tested were designed under the J.P. Teas system, with control of the forces of dispersion (fd), polar (fp) and hydrogen (fh), to help define the best method of intervention in the removal of vandalism without damaging the underlying chromatic layers. Results have shown that several solvent mixtures are needed, for specific scenarios depending on the thickness of the vandalic layer, binder of the ink and the operator control. The best protective coating and solutions were selected within various commercial paints and applied in a case study of an artwork in Porto. “Virtus”, a mural by Hazul was selected for case study. This work presented several pathologies, related with the use of spray paint, vandalism, stickers, permanent marker and a burnt area. It also presented other pathologies of physical and biological origin, therefore an intervention was carried out, aiming the stability and the aesthetic integrity of the artwork, while electing green cleaning methodologies and strategies.
Date of Award25 Feb 2021
Original languageEnglish
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorPatrícia R. Costa (Supervisor), Eduarda Vieira (Co-Supervisor) & Andrea Macchia (Co-Supervisor)


  • Mural art
  • Aerosol ink
  • Green solvents
  • Coatings
  • Vandalism
  • Hazul
  • Porto


  • Mestrado em Conservação e Restauro de Bens Culturais

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