What are the causes of rusty copper doors? What causes copper rust

Before leaving the factory, the surface of the copper door will be treated with anti-oxidation, and after the copper plate is colored, it will be sprayed with fluorocarbon paint at least twice, and then baked at high temperature to harden the paint layer. Therefore, under the condition that the owner uses it properly in daily maintenance, the copper door will generally not be oxidized and rusted. If it does not affect the overall appearance of the copper door, there is no need to worry; Is there a difference between patina and rust?

Once the iron door is rusty, if it is not treated in time, the iron plate will slowly erode and fall away; The copper door is rusty, and the patina is actually a protective layer, which plays a certain role in protecting the texture inside. If there is a large area of oxidation and rust on the copper door, and the product is still under warranty, you can contact the merchant or manufacturer to deal with it, and it will be properly handled. When the copper door is rusted for a long time, it often contains a layer of rust, which is difficult to wash off with conventional methods.

At this time, you can use a wet towel to soak it in boiling water at 100 degrees, then apply a towel to the rusty copper door, and then scrub it with a small soft brush. Note that it is best to wear heat-insulating gloves for this process to prevent your hands from being burned by boiling water, and if you can't wash off the patina at one time, you can soak it several times.

Rust is a mixture of earth and patina. Speaking of "rust", I am reminded of unearthed artifacts, where porcelain or bronze objects are buried in damp soil for too long, and rust will develop on the surface. If we reason in this way, unless we bury the bronze door in the earth, so that a layer of rust will rise over time.

Moreover, the method of applying a hot towel to the surface of the copper door is also inappropriate, and the high temperature is very easy to destroy the paint layer on the surface of the copper door. Although the copper door has good corrosion resistance, if the copper door is not maintained for a long time, there will still be a layer of shallow patina in a few years. When encountering this kind of shallow patina, you can use a large brush or a soft paint brush to dry brush the rust.

The brushing process should be evenly forced, wash with water after brushing, and then dry with a towel. In the process of daily use of the copper door, the hard object touches the surface of the copper door, which may damage the paint protective layer on the surface of the copper door, which will lead to the "patina" phenomenon at the bump. These are caused by improper daily maintenance of copper doors.

Before leaving the factory, the copper door will have surface pre-oxidation treatment. That is, spray baking protective paint on the surface of the copper plate to prevent oxidation and rust on the surface of the copper door. Under normal use, if the paint protection layer on the surface of the copper door is not damaged, the copper door will not appear oxidized and rusted for a long time.

The oxidation and rust of their own copper doors has a lot to do with improper daily maintenance, and even many owners have never maintained their copper doors. Rolls-Royce, Bentley, LV, Chanel and other top famous cars and brand-name bags all need daily maintenance, not to mention the "copper door". Whether it is a big brand or a small brand, the copper door has been used for a long time, and it is normal for the phenomenon of oxidation and rust, which is determined by the characteristics of copper, the paint is only to isolate the air from the chemical reaction with the copper plate, once the paint protective layer is destroyed, the copper door oxidation and rust is inevitable.

How can the copper door be rusty, probably everyone's first reaction. Yes, copper doors are indeed not easy to rust, but if the copper doors are used for a long time, or if they are not usually well cared for, some rust will also appear. That is, the copper door is oxidized.

Anyone who has studied chemistry knows that the main component of patina is basic copper carbonate [Cu2(OH)2CO3], which reacts with acids to form copper salts, water and carbon dioxide. Then vinegar is a weak acid, and the weak acid can react with patina to form copper salts, water and carbon dioxide that dissolve in water. So after the vinegar is applied for 24 hours, add water with a brush to remove the patina.

However, this method can only be used on copper doors that are not too rusty. Sometimes the rust on the copper door is soil embroidery, in this case, you can rinse it with boiling water at a temperature of 80 to 90 degrees Celsius, and then use a brush to clean it. If the soil embroidery is very thick, then rinse it several times with boiling water at a higher temperature, so that the soil embroidery will fall off slowly.

Copper rust is caused by copper coming into contact with water, oxygen, and carbon dioxide.

The so-called rust of copper is that copper will rust when it reacts with oxygen, water vapor and carbon dioxide in the air in a humid environment to produce basic copper carbonate [Cu2(OH)2CO3], that is, patina, which is green.

The chemical equation for this reaction is: 2Cu+O2+H2O+CO2===Cu2(OH)2CO3

Basic copper carbonate is malachite green, so it is also called malachite, which is a precious mineral gemstone. It is a substance produced by the reaction of copper with oxygen, carbon dioxide and water vapor in the air, also known as patina, and its color is emerald green. Aerina decomposes into copper oxide, water, and carbon dioxide when heated in air.

It dissolves in acid and generates the corresponding copper salt. It occurs in nature in the form of malachite.

Cu2(OH)2CO3=2CuO+H2O+CO2 (Condition: Heating) Cu2(OH)2CO3+4HCl=2CuCl2+3H2O+CO2

Rust of the copper door will produce patina, which will protect the copper door, and the copper door is not easy to corrode and become brittle.

The surface of the copper door will be treated by a high-temperature baking paint process before leaving the factory, and if the protective layer is not damaged, the copper door will not rust under normal conditions. Rust of the copper door will produce patina, patina will play a protective role in the copper door, with patina, the copper door is not easy to corrode, brittle, but in the atmosphere naturally formed patina, it takes about 30 years.

Although the patina produced by the rust of the copper door has such benefits, compared with the copper door treated with modern paint, the aesthetics and corrosion resistance are greatly insufficient, so the process progress is still reasonable.

How to restore the rust of the copper door.

The first type: household vinegar wetting - first wash the rusty copper door with clean water If the plate of the copper door can be moved out, pour a small amount of edible vinegar into a small dish, brush it on it evenly, soak it as much as possible (soak it better), after 24 hours, brush off the rust with a small brush, and then wash the vinegar with water, wipe it clean and dry.

The second kind: boiling water soaking method - rusty copper is sometimes covered with a layer of rust that is not lost, at this time, you can put the rusty into the basin first, and then pour the boiling water with a temperature of 80 to 90 until it is submerged, take it out after 5 minutes, brush it with a small brush, dry it in the shade, and if the rust is serious, you can also heat the water to boil to make the rust fall off.

The third way: dry brush method - the specific method is to choose a Chinese New Year's Eve oil brush, on the cymbal to cut the brown hair on the tip of the brush to a centimeter from the root can be used, first fix the rusty brush, hold the root of the oil brush evenly brushed, to pay attention to force, otherwise the effect is not safe, and then wash with water.

1. There are some dust, phlegm and other noisy objects on the surface of the stainless steel telescopic door, if it is oxidized and acid, it will corrode the stainless steel surface for a long time and form rust.

2. There are some acidic or alkaline substances on the surface of the stainless steel telescopic door, and long-term corrosion will also show mottled corrosion.

3. The appearance of stainless steel is rich in other metal elements or appendages, and in the humid air environment, a series of chemical changes will occur, which will also cause the film on the surface of stainless steel to be damaged and corroded.

4. Even if it suffers from sulfuric acid and nitric acid, it will also affect the appearance of the stainless steel telescopic door and will be mottled.

The cause of metal rust is mainly the effect of electrochemical corrosion and air oxidation, and pure metal or active metal is mainly due to the oxidation reaction between the metal surface and the oxygen in the air, and the metal clean oxide is generated on the metal surface, that is, rust. If the metal contains more impurities, these impurities will form a chemical galvanic battery with the metal, and electrochemical corrosion will occur, thereby oxidizing the metal to form metal oxides.

Some metals, such as alumina, can rust and produce a dense oxide film that prevents further oxidation. However, the oxide film produced by some metals after rusting is sparse and the metal oxidation is faster, such as: iron is rusting.