Influence of the Application and Preparation of Wax Coatings Artificially Patined Bronze Surfaces D. A. Jáuregui-Gónzalez Coordinación Nacional de Conservación del Patrimonio Cultural (CNCPC–INAH) Xicotencatl y General Anaya s/n San Diego Churubusco Coyoacán, 04120, DF, MÉXICO diegoarturo_df@yahoo.com http://conservacion.inah.gob.mx/ M. López-Arriaga* Escuela Nacional de Conservación, Restauración y Museografía (ENCRyM-INAH) General Anaya 187 San Diego Churubusco Coyoacán, 04120, DF, MÉXICO marcela_lopez_a@encry.edu.mx http://www.encrym.edu.mx *Author for correspondence F. J. Rodríguez-Gómez Departamento de Ingeniería Metalúrgica, Facultad de Química, Universidad Nacional Autónoma de México Edificio D Circuito de la Investigación Científica s/n Ciudad Universitaria, Coyoacán, 04510, DF, MÉXICO fxavier@unam.mx http://www.quimica.unam.mx/ J. Contreras-Vargas Escuela Nacional de Conservación, Restauración y Museografía (ENCRyM-INAH) General Anaya 187 San Diego Churubusco, Coyoacán, 04120, DF, MÉXICO jannen_contreras_v@encrym.edu.mx http://www.encrym.edu.mx P. Roncagliolo-Barrera Departamento de Ingeniería Metalúrgica, Facultad de Química, Universidad Nacional Autónoma de México Edificio D Circuito de la Investigación Científica s/n Ciudad Universitaria, Coyoacán, 04510, DF, MÉXICO fxavier@unam.mx http://www.quimica.unam.mx/ Introduction Over the years, in Mexico, a variety of petroleum and synthetic waxes have been used for protecting copper alloys outdoors, and have also been applied on museum silver object collections (Rossell 2012). The use of wax coatings is based on observations that suggest waxes retain barrier proprieties and resist environmental exposure better than resins. In the Mexican context, a commonly used wax has been the paraffin Ozokerite 1899, a material chosen by Contreras (2009), trying to find a material similar to those employed by Mach (2006); however, microcrystalline and synthetic waxes have also been used. The aim of this research is to produce conservation oriented data about the features of the wax coatings being used in Mexico, which resemble those used in other countries, as well as specific information of how the temperature of the application and the presence of dissolvents and fillers affect the permeability, topography and abrasion resistance of wax coatings. Performance of the protection coatings Coatings protect in three main ways: as a barrier, by inhibition, and by cathodic protection (González 2010, 20). A protective coating acts only as a barrier, whereas an anticorrosive usually has all the three effects, generating chemical reactions on the metal surface. Most conserva- tion coatings, including waxes, form only barrier systems, because inhibition and cathodic protection involve changes in appearance and re-treatability. All barrier coatings aim to block the access of oxygen and water to the metal surface, preventing electrochemical reactions. This effect is limited because organic films are permeable to corrosive agents, which not only diffuse Abstract The paraffin Ozokerite 1899 (Kahl & Co), by itself and mixed with microcrystalline wax 1847 (Kahl & Co), synthetic wax MP-22 (Micro Powders Inc.) and fumed silica cab-o-sil were applied in dissolution, either heated or at room temperature, on artificially patined bronze coupons. The layers obtained were evaluated via electrochemical impedance spectroscopy (EIS), optical microscopy and abrasion tests to get data about the way such preparation and application affects the wax coatings’ features. Keywords bronze, coatings, paraffin, microcrystalline wax, synthetic wax