Four methods for maintaining bronze sculptures

　　I. Silver Oxide Method

　　Use silver oxide in contact with cuprous oxide to seal the exposed surface of cuprous chloride, achieving the goal of controlling corrosion of bronze sculptures. First, mechanically remove powdery rust to reveal the grayish-white waxy cuprous chloride. Then, mix silver oxide with alcohol to form a paste, apply it to the surface of cuprous chloride, and place it in a humid environment to allow it to react fully, forming cuprous oxide and copper chloride, covering the surface of cuprous chloride. Both are stable salts. Repeat this operation multiple times until no powdery rust corrosion points appear when the object is placed in a high-humidity environment. This method is suitable for objects with spot-like localized corrosion and objects with metal inlays.

　　II. Benzotriazole Method

　　Benzotriazole is a heterocyclic compound that forms stable complexes with copper and its salts, creating an insoluble and quite durable transparent protective film on the surface of copper alloys. This inhibits and stabilizes bronze disease, preventing erosion by water vapor and air pollutants. Use distilled water and organic solvents such as toluene and acetone to clean dirt and oil from the bronze sculpture's surface, then immerse it in a benzotriazole alcohol solution for penetration, which will form a complex protective film. However, benzotriazole is prone to sublimation when heated, losing its protective effect, so a layer of polymer material should be applied to the bronze sculpture's surface as a sealing film.

　　III. Alkaline Solution Immersion Method

　　Immerse the corroded bronze sculpture in a sesquicarbonate of soda solution, allowing the copper chloride to gradually convert into stable copper carbonate, and the chloride ions of the bronze sculpture are displaced into the immersion solution. The immersion solution needs to be replaced regularly until no chloride ions appear in the solution. Afterward, repeatedly wash the object with distilled water to remove the alkaline solution, then dry and seal it. The alkaline solution only extracts chlorides, retaining colorful corrosion layers such as malachite, without damaging the original appearance of the bronze sculpture. The disadvantages of this method are the long displacement reaction time; moreover, chlorides are not only attached to the rust layer surface but have also penetrated deep into the corrosion crust of the object, making them difficult to displace.

　　IV. Combination Method of Coconut Oil and Distilled Water

　　First, pour a small amount of coconut oil onto a clean, soft cloth and gently wipe. This helps with the self-maintenance of bronze sculptures. Coconut oil is used because the substances it contains will not cause discoloration of the copper, which is very important to note. Regularly wiping the copper with a soft cloth dipped in distilled water is also very important. At the same time, we can also add some mild soap to the distilled water for cleaning dirt. For corners that cannot be reached, we can use a soft brush for treatment, which will effectively clean and protect the bronze sculpture.