When slight rust appears on the surface of forged copper sculptures (mostly brownish red and green oxide layers, without forming deep corrosion), the method of "mild rust removal+timely protection" should be adopted to avoid expanding the damage due to improper treatment. Firstly, it is necessary to determine the type of rust: if it is surface floating rust (which can be easily removed by wiping with your fingers), you can first use a soft cloth dipped in a small amount of neutral soapy water to wipe off the surface dust and oil stains, and then dry it with a clean dry cloth; If the rust is stubborn (tightly attached), a specialized copper rust remover (a neutral, non abrasive product such as copper cleaning paste) can be used. Take a small amount and apply it to the rust area, let it sit for 1-2 minutes (do not stay for a long time to prevent corrosion of the copper material), and then gently wipe it clockwise with a soft cloth until the rust disappears. During the process, avoid excessive friction to prevent damage to the texture and oxide layer of the sculpture surface. If you are concerned about chemical damage, you can also use physical rust removal method: mix flour and white vinegar in a ratio of 3:1 to form a paste (white vinegar needs to be diluted, high concentration is easy to corrode), apply it to the rust area, let it stand for 5 minutes, and gently wipe it with a soft cloth. The adsorption of flour can take away the rust, and the weak acid properties of diluted white vinegar soften the rust, while reducing damage to copper. After rust removal, protective treatment must be carried out: use a damp soft cloth dipped in water to wipe off residual rust remover or paste substance, thoroughly dry with a dry cloth, and after the surface is completely dry (about 2-3 hours), apply a thin layer of transparent copper protective agent (such as silicon-based protective agent) to form a protective film and delay further oxidation. Attention should be paid that slight rust should be observed for 1-2 weeks after treatment. If the rust does not appear again, it can be maintained according to the normal maintenance frequency; If the rust is repeated, it is necessary to check whether there are problems such as humid environment and damaged coating, and solve the root cause in a timely manner.
