Metal products corrode during operation. As a protection against this, the metal is galvanized. The technology of such processing at home is quite affordable. It is important to choose the right processing option.
What is zinc plating
All metal elements are exposed to varying degrees of corrosive processes. You can't do without it. And this process can only be delayed. It is for this purpose that zinc treatment is used. This choice of substance is not accidental. The choice is made on the basis of the characteristics of two components: steel and zinc. Zinc has a more electronegative charge than steel. When a zinc coating is applied to metal products, a galvanic bond is formed between the metal and zinc. Due to this, under the influence of external environmental factors, zinc enters into the reaction. Chemical reactions involving steel slow down. And so it will continue until the zinc coating is completely destroyed.
When the zinc coating breaks down, the protection continues. This is due to the fact that zinc reacts with atmospheric oxygen. As a result of chemical processes, zinc hydroxide is formed. And this substance also has protective properties. Thus, the galvanizing of the metal continues to work.
Zinc coating methods
Zinc coating of metal products is the most popular way to combat corrosion. This is due to the ratio of a high test result and affordable cost. The following metal galvanizing methods are used:
- cold;
- hot;
- electroplated;
- thermodiffusion;
- gas thermal.
To choose the most suitable option for yourself, you must first analyze the conditions in which the product will be used in the future. The quality of galvanizing depends on the coating thickness, protection time and temperature. Do-it-yourself galvanizing of metal is possible only in two ways: cold and galvanic. It should be noted that the durability of the part treated in this way will depend on the operating conditions. The zinc layer is easily exposed to mechanical stress.
Hot way
Hot galvanized metal is the most practical option. Chemical reagents are used to treat the surface of the product. With their help, the metal is prepared for the main part of the process. It is because of this that an environmental problem arises. For the process, straightened zinc is used. The prepared product is simply lowered into a bath of moltenzinc.
This process requires special equipment. Therefore, this method is not suitable for galvanizing metal at home.
Thermodiffusion method
Galvanizing metal in this way involves the penetration of zinc atoms into the structure of a metal product with the formation of an iron-zinc alloy with a complex structure. The whole process takes place at very high temperatures. At a temperature of more than 2600 degrees, zinc passes into a gaseous state. The closed space where metal products are located is filled with zinc-containing powder. Suitable method for applying a layer whose thickness exceeds 15 μm. The resulting protective coating in terms of stability can be compared with a layer applied by the hot method. Due to the need to create certain conditions, the method is not suitable for self-implementation.
Gas-thermal method
With this method, zinc, which is in the form of a powder, is sprayed with an air stream over the surface of metal products. Before spraying, the substance is melted due to high temperature and already in this state it falls on the parts. Galvanizing metal in a similar way is typical for those cases where metal products have large dimensions.
Feature of the method is that the protective layer has a large number of pores. To fill them, the product is covered with paints and varnishes. This layer of two materials is capable ofpersist for 30 years. This method cannot be implemented at home.
Cold galvanizing at home
There is also cold galvanizing. Galvanizing metal in this way involves applying zinc to a metal product in the form of paint. Manufacturers offer a wide range of these funds. And the main indicators of the compositions (for example, the mass fraction of zinc in a substance) can differ greatly from each other. It becomes clear that the effect of processing will also be different.
Means for galvanizing have a number of features. Some require high quality product preparation. The latter have low adhesive abilities, which is why, after drying, they begin to peel off. Still others, after application, are covered with a "cobweb" of cracks. The fourth can work together only with solvents of a particular type. Fifths require the application of special equipment.
This tool is a two-component. Therefore, before application, the two substances (powder and binder) must be mixed together. Do this in a ratio of 3 to 1 or 1 to 1. The whole process should be carried out only under certain conditions. The air temperature should be positive and be in the range from 5 to 40 degrees. At the same time, air humidity ranges from 30 to 98%. The room in which the process is carried out must be well ventilated. After work, it must be thoroughly ventilated. The agent is applied in two layers with an interval of approximately 30 minutes. After a day, the product can becover with paints. When galvanizing, safety regulations must be observed. All work is carried out using personal protective equipment.
Galvanic method
Galvanization of metal at home can be done by galvanizing. To do this, the product must first be cleaned. After that, the part is lowered for a few seconds (from 2 to 10) in sulfuric acid. After that, the product is washed in water. This completes the preparation for anodizing. For installation under galvanizing, it is necessary to choose dishes from inert materials, for example, glass. The container is selected in such a way that a part with an electrode attached to it can fit in it.
The current source will be a charger for 6-12 V and 2-6 A. Next, an electrolyte is prepared - a solution of any s alt soluble in water. In practice, it is better to take zinc s alt. You can take diluted sulfuric acid (as in a battery) and add zinc there. As a result of a chemical reaction, the acid will turn into an insoluble s alt and precipitate. And zinc will remain in solution. The precipitate must be removed by simply straining the solution.
The zinc electrode is made from a piece of zinc attached to a copper wire. From the charger, “minus” is brought to the part, and “plus” to zinc. Thus, the zinc electrode will dissolve, and all the zinc atoms will settle on the parts.
Conclusion
Galvanizing metal at home is a very real process. To implement it, you will need to purchasesome materials. For example, zinc-based paint for a cold process or a piece of zinc for electroplating. By the way, zinc can be purchased at any scrap metal collection point.
