Imparare in cantiere. Il San Miniato di Bernardino Poccetti in San Bartolomeo a Monteoliveto, Firenze

Our SAFS (Scuola di Alta Formazione e di Studio – Higher education School) course in 2022 dealt with the restoration of a group of paintings in the church of San Bartolomeo in Florence. In particular the painting of San Miniato painted by Bernardino Poccetti, placed on the counterfaçade of the church, attracted our interest as it showed widespread deterioration due to the presence of calcium sulphates in the paint flm. Our intervention focused on a remedy for the degradation caused by salts. First a pre-consolidation of the powdery surface was carried out with nanometric calcium hydroxide in alcohol dispersion. The ammonium/barium method developed in our institute was then carried out with applications of solutions of ammonium carbonate and bicarbonate, in order to improve the removal of salts, followed by a treatment with barium hydroxide solution to passivate the residual salts. By analysing the technique of drawing on plaster, we also related the painting under the high altar of the church to the manner of Bernardino Poccetti.