Cold do-it-yourself galvanizing

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Corrosion of iron occurs when it interacts with atmospheric oxygen. To avoid this and extend the service life of the product several times, it is necessary to carry out a set of protective measures. Usually zinc plating is used. This process consists in applying a layer of zinc to the surface of the product. This process can take place in various ways.

Varieties of operation

Today, progressive developments of scientists allow the use of the following types:

- cold galvanized metal;

- hot;

- diffusion;

- electrolytic;

- shopping;

- gas dynamic.

We'll talk about each method separately later.

Description of types of galvanizing

Two types can be considered common - hot and electrolytic. In this case, the first method, also called galvanic, requires the construction of a whole production line. But this method is ineffective against corrosion. However, it gives the product a beautiful and shiny appearance. So electrolytic galvanizing is used only for decorative purposes.

Hot galvanizing is a very expensive undertaking. For histhe part must be completely immersed in the molten zinc. Such a process is carried out only on an industrial scale and requires a lot of energy and labor. The surface of the product is not glossy, but matte. But the layer is so strong that it can be compared to corrosion resistance with stainless steel.

Hot and cold galvanizing has proven itself as a means to protect metals. When zinc powder or steam is applied to the surface of a product using high temperature, this process is called diffusion coating. If the zinc in the molten state is applied with a gun, like dyeing, then this is shopoping.

Zinc deposition process using supersonic flow - gas dynamic coating. This method has increased adhesion and is very beneficial in this regard in comparison with others.

All of the above methods can be easily deployed on an industrial scale in a special production, but at home, these processes will be very difficult to use, and in some cases simply impossible.

In order for a metal structure to meet the stated requirements and service life, it must be manufactured in accordance with the terms of regulatory documentation. Such requirements are clearly stated in GOST.

Cold galvanizing is the most common and affordable way to protect iron from corrosion. It does not require special equipment and complex technological processes. The application of a zinc-containing composition is notharder than painting.

The content of the composition, which is used for cold galvanizing of metal, is clearly regulated by GOST. It must contain at least 94 percent zinc.

What is this item?

Zinc is a chemical element belonging to the group of metals. It has a silvery white color. In its pure form, it has a rather fragile structure. It reacts with atmospheric air, namely with its components: carbon dioxide and oxygen. Due to this reaction, an oxide appears on the surface of the part, which has a high bond strength and is not subject to dissolution.

The electrochemical potential of zinc is halved compared to iron. Therefore, the pair of compounds is the anode in the form of zinc and the cathode is iron. When exposed to atmospheric moisture, zinc reacts with it, and carbonate is formed. It is he and his oxide that do not dissolve, but cover the product with a film.

Pros of cold processing

- The main advantage of the cold galvanizing method is that there are no restrictions on the volume of the workpiece.

- There is no need to dismantle the product and deliver it to the place of processing. Everything can be done stationary.

- The surface galvanized in this way does not interfere with welding work. Weld seams can also be treated.

- Cold working of metal structures with zinc takes place at a comfortable temperature - from -20 to + 40 degrees.

- Coatingeffectively protects against corrosion, and itself is not subject to serious deformations, as it turns out to be very elastic.

- Cold galvanizing allows you to apply various coloring compositions to the surface.

- Work can be done independently, without special equipment and machinery.

- Cold galvanizing GOST 9.305-84 is clearly regulated in terms of composition and properties.

- Low cost.

Processing by yourself

Such a coating that protects the metal from corrosion can be carried out at home, while observing precautions. In addition to the cold method, galvanic treatment can be carried out. But you need to keep in mind that such an electrolyte is an extremely toxic substance. It must be handled carefully and carefully, be sure to have personal protective equipment.

The construction market presents a wide range of tools that allow cold galvanizing of metal structures at home. Sometimes the content of the main element in them differs in a wide range. Accordingly, the lower its percentage will be, the lower its percentage.

Such compositions may have other disadvantages:

- the need for more thorough preparation of the part;

- poor adhesion to metal, as a result of which microcracks form on the coating due to poor elasticity;

- some manufacturers use only a specific solvent, which complicates the work;

- some require a special machine to apply;

- othersjust not intended for further painting.

Galvanol

Good performance and consumer recommendations, has a material such as "Galvanol".

Its properties:

- has a high content of pure zinc powder, which reaches 96%;

- fast drying, before applying the next layers you need to wait no more than half an hour;

- it is possible to apply such cold galvanizing by any known method: brush, roller, immersion or spray gun;

- suitable for further painting with paints and varnishes, as well as polymer coatings;

- can be applied without prior rust cleaning;

- does not lose its properties when applied at low temperatures (up to -35 degrees), as well as with humidity on parts;

- does not require a special solvent. Suitable universal, such as solvent or xylene.

Consumers conducting cold galvanizing with this composition leave mostly positive reviews. Metal resistant to corrosion for several years.

How it is made

Processing technology:

- liquid zinc is well mixed, because it has a high density and exfoliates. It is necessary to obtain a homogeneous liquid mass. How well the material is prepared to protect the product depends on how long this anti-corrosion layer will last;

- mechanically clean the part;

- degrease the surface in any way possible;

- apply the next layer of the composition no later thanafter half an hour. Protection in two layers of zinc will last at least 10 years;

- the final layer, which will give the product a finished look, apply better after waiting a day.

When cold galvanizing is performed, the technology must be followed. Only after that the result of homework will be indistinguishable from the factory one.

Galvanic

Any galvanizing requires great care and precision, especially at home. The current source for this method can be a car battery or any charger with power up to 12 V.

S alt is suitable as an electrolyte. But it is better if it is zinc. To make it you need:

- zinc sulfate - 200 g;

- magnesium or ammonium sulfate - 50 g;

- sodium acetate - 15 g;

- liter of water.

You can make s alt by another method by placing zinc in the battery electrolyte and waiting for the reaction to complete, after which the acid will be converted into s alt. However, its concentration can be high. Then the s alt is diluted with water.

Important! Electrolyte is a poison, work with it must be done with extreme caution. The room must be well ventilated when working.

Dishes for processing should be glass or special plastic. A zinc electrode is attached to it. With a small amount of detail, a simple household jar is suitable. The part must be well cleaned and degreased. It should be lowered into the prepared solution for no longer than 10 seconds. Thentake out and rinse thoroughly with water. After that, you need to anodize the part. For this, a zinc electrode is made, connected to a power source. The formation of a zinc film occurs within 10-40 minutes.

Cost of cold galvanizing compounds

As part of the "Barrier-zinc" content of the active substance - 96%. The term of protection is from 10 to 50 years. It is highly economical, as it has a consumption of only 1 kg per 4 m2. Cost - from 300 rubles per kilogram.

"Zinol" - zinc-containing paint with 95% content of the active substance. Cost - from 340 rubles per kilogram.

Zinga is a Belgian-made composition that allows for cold galvanizing and has all the necessary properties to protect metal from corrosion. Cost - from 576 rubles per kilogram.

Already mentioned by us "Galvanol" is the most popular remedy among analogues. It has 96% zinc content in the composition and all the necessary properties. Cost - from 390 rubles per kilogram.

"Zinotan" - contains only 85% zinc. Cost - from 380 rubles per kilogram.

Protective compositions based on zinc are available in a huge range. The price depends not only on the content of zinc, but also on the popularity of the producing brand. Another composition that allows cold galvanizing is Zinol.

How to choose the right one

When buying the necessary funds, it is better to pay attention in advance to its composition anddeclared properties. Color shades do not differ in variety, mainly matte gray. Consumption during application is almost the same - no more than 300 g/m2.

Therefore, these criteria cannot be considered key when choosing, but what really matters:

- service life;

- cost;

- drying time;

- zinc content;

- shelf life;

- application conditions.

Conclusion

So, we found out how cold galvanizing of metal structures is performed. As you can see, this is a great way to protect the metal surface from the negative effects of corrosion, thereby increasing its service life.