The main objective of the « painted metals » project is to develop a treatment protocol in order to stabilize the metallic support of painted metal objects without impacting on the polychromatic coat of paint.

This type of object is common in heritage collections. Following a field school carried out by the earthenware specialty (metal) of the Inp, the study focused on the protection of painted metallic objects housed in the scientific and technical collections of the « Musée des arts et métiers » (CNAM). 

Painted metal objects conserved in museums are treated as composite objects. It is therefore necessary to determine the origin of alterations present before any restoration treatment begins (degradation of underlying metal, degradation of painted surface or degradation linked to an interaction between the two metal supports). When observed alteration phenomena is found on a metal support, a product is often applied in order to stabilise corrosion : corrosion inhibitor or protective coating (more commonly used in the restoration of metallic objects).  

For some years now carboxylates have been used as a corrosion inhibitor. Derived from fatty acids vegetable oil extracts, they are non-toxic and have proved to be effective on both healthy and corroded metals. It is now a question of studying their impact on a pictorial layer (colour, stability) before a protocol for restoration on painted metals can be validated. 

First of all, the project aims to compare different products (a corrosion inhibitor and protective coating) in order to characterize the stability of these products and their effects on tests composed of pigment mixtures/binders before and after ageing. 

In parallel, the project will also focus on the effectiveness of these products in their anticorrosion role on composite test specimens by simulating atmospheric corrosion in a climatic chamber. 

In a second phase, these results will then be compared to real systems within the CNAM collections.

This project brings together professionals in conservation-restoration and scientists from different public institutions and laboratories. These partnerships provide access to advanced techniques to allow for a chemical and structural characterization of the products formed in order to better understand the mechanisms of protection.

PROJECT LEADERS

Synchrotron SOLEIL, Ligne DiffAbs, Division Expériences with Solenn Reguer, researcher, beamline scientist

PARTNERS

Synchrotron SOLEIL, Ligne DiffAbs, Division Expériences, with Solenn Reguer, Jacqueline Riddle, Laura Normand

National Institute of Cultural Heritage (Inp), Departement of conservators, with Anne Genachte-Le Bail, Marie-Anne Loeper-Attia, Sigrid Mirabaud, Marie Fays, Marie Grima, Julia Jouet

Musée des arts et métiers (arts and crafts), Conservatoire national des arts et métiers (Research Institute) , with Remi Catillon, Anne-Laure Carré

Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583

University Paris-Est Créteil and University Paris Diderot, with Mandana Saheb

MONARIS, UMR 8233, " From molecules to nano-objects: responsiveness, interactions and spectroscopy

University Pierre et Marie Curie (Paris 6), with Ludovic Bellot-Gurlet

Independent heritage conservator, earthenware (metal) specialty, Anne-Marie Geffroy 

Institut Jean Lamour (IJL), UMR 7198, Université de  Lorraine-CNRS, with Emmanuel Rocca

 Centre for Research and Restoration of the Museums of France (C2RMF), with François Mirambet

FUNDING

Synchrotron SOLEIL – stage master 2 in 2017

DIM « Matériaux anciens et patrimoniaux » (MAP) (Heritage and ancient materials), région Ile-de-France – stage master 2 in 2018