INFN-CHNet is the cultural heritage network of the Italian National Institute of Nuclear Physics (INFN) and is constituted by units from Italy and from outside Europe, one of them at Universidad Nacional de San Martín (UNSAM) in Buenos Aires, Argentina. As a result of the initiative carried out during 2015 by the Accademia dei Lincei for the year of the Italian culture in Latin America, an INFN-CHNet laboratory was set at CEPyA-UNSAM with the collaboration of INFN and the Restoration Workshop Centro Tarea. Noteworthy, this laboratory is conceived as a multidisciplinary research facility with complementary skills, both scientific and humanistic. In this context, the first instrument jointly set up, optimised, and applied to Cultural Heritage was an X-ray fluorescence scanner. In this manuscript, we describe the instrument and its main features together with a set of representative yet novel applications in the field of cultural heritage, namely, the experimental study of hidden rock art through laboratory replicas that imitates the problems found in the archaeological sites (hematite drawings hidden below carbon deposition); the study and chemical characterisation of archaeological decorated pottery; and finally, the application of the XRF scanner to ancient photography, for quick and accurate identification of materials and techniques employed. Beyond these specific results, the primary output of this initiative has been the conception of a future network of scientific laboratories in South America, coordinated by CEPyA at UNSAM.