Due to their historical importance, the artillery cannons manufactured in grey cast iron are exhibited in public open places at the San Francisco de Campeche city, Mexico, where a hot, humid tropical climate prevails, which is classified as causing a medium to high level of corrosion. During this research, several analyses were carried out to grey iron cannons in order to determine the chemical composition of their corrosive products. The electrochemical tests were used to understand the behavior of the cannons’ metal under the rain, and also to evaluate the formation of stable patinas using 5% NaOH and a 5% tannic acid solution. Furthermore, a conservation strategy was implemented, that set in action a maintenance and a preservation program for a collection of 107 cannons, all which was based on scientific results derived from the above-mentioned research and on the inter-institutional collaboration of the Universidad Autonoma de Campeche (Autonomous University of Campeche), the government of the stat of Campeche, la Secretaria de Desarrollo Social (Secretariat of Social Development), and el Instituto Nacional de Antropologia e Historia (National Institute of Anthropology and History) (all of them institutions in Mexico).