Testing of a new Yb:YAG fiber laser system for the removal of graphic vandalism from marble

Abstract Graphic vandalism causes detrimental effects on architectural stone surfaces. Among the cleaning methods developed in last decades, laser showed considerable effectiveness but available equipment still lacks full adaptability for use site, while process is time-consuming site work requirements. In this paper, feasibility of a fiber operating at 1064 nm (Yb:YAG) high repetition rate (kHz) removal vandal graffiti from marble investigated, as it potentially suitable large Indeed, device exploits scan system covering wider area than that solid state lasers, maintaining excellent portability. Evaluation procedure selection spray paints and felt-tip permanent markers applied mock-ups carried out with multimodal approach (optical microscopy combined surface pattern reconstruction, colour monitoring, Fourier Transform Infrared spectroscopy external reflection ATR mode, Thin Layer Chromatography, Raman spectroscopy, thermal scanning electron microscopy). Ablation are observed varying setting type paint layer, showing strong impact interaction. Overall, best procedures achieved thinning black marker paint. Some residues results were observed, suggesting needs to be integrated second step chemical cleaning. This study, focused removal, shows can useful tool monumental Graphical