In 1934, Jean Capart, curator of the Royal Museums of Art and History of Brussels, invited him to assemble a laboratory and to reorganize the RMAH's system for photographic artifacts.

Analysis through radiography, thermography, and ultraviolet light enabled Capart to study objects quickly; he published his results in the Bulletin des musées (Journal of the Royal Museums of Art and History).

All the while, Coremans took pertinent courses: metallography at ULB; spectroscopy at the University of Liège; history of Flemish painting in the fifteenth century at the Royal Museums of Fine Arts of Belgium.

His team fulfilled emergency missions to save fragments of the Saint Gertrude of Nivelles shrine, and mural paintings in the churches of Saint-Brice and Saint-Quentin in Tournai.

This led to drafting a series of directives published in 1946 in the handbook La protection scientifique des œuvres d'art en temps de guerre; l'expérience européenne pendant les années 1939 à 1945.

In the same year, Coremans was appointed as an expert in the trial of the forger Han van Meegeren, which earned him great fame afterwards, but also numerous attacks emanating from collectors who had been duped.

This experience of the meeting between hard and social sciences led him to reorganize the ACL into three departments: Documentation, Conservation-Restoration and Laboratories: the concept of interdisciplinarity was born.

Between 1951 and 1954, he participated actively in the creation of the Brussels Art Seminar, a university programme established by the Belgian American Educational Foundation, where he proposed courses in techniques used in painting.

For Coremans, it was mainly the opportunity to rationalize and to develop the training activities of the Institute, by creating a regular programme of post-graduate courses in scientific examination and the preservation of cultural property.