Which welding rod should I use for thin metal? Welding of thin metal is a very important and relevant field of activity these days. It is absolutely important to know how to cook sheet metal of 1, 2 and 3 mm, which electrodes are better. The technology of sheet welding includes not only the determination of the required polarity, but also a number of other subtleties.
Which welding rod should I use for thin metal: Welding of thin metal with an electrode
A conversation about welding thin metal should start with the fact that this is a very complex procedure. Even experienced specialists face serious difficulties. What can we say about those who are just starting their professional career?
Welding works with thin-sheet metal products differ fundamentally from work with thicker objects. The nuances relate to the modes, and the equipment used, and electronic tools.
Sheet metal can be used to produce a variety of products. An example is cooking a car body, obtaining a liquid container and some other points. Working with thin sheet material creates quite a lot of problems.
Before starting the work, the welder must select the most suitable electrode, select the appropriate mode of operation of the device. Only if all these points are taken into account, you can get a quality product that will meet all the established standards.
Included in this article
- Features of working with sheet iron
- Techniques and methods of welding thin metal sheets
- Galvanizing welding
- Electrodes used
- Selection of modes and electrodes
- Machine modes and welding parameters
- Welding technique
- Problems of welding thin-walled products
Features of working with sheet iron
Not all specialists are able to work with steel, the thickness of which is 1-1.5 mm. In order to obtain the required product when using such blanks, you should know the specifics of the procedure. The peculiarities of welding thin metal are associated with difficulties, which consist in the following factors:
- Burnouts can be called the most common defect that can be found when working with thin metal. A similar problem is associated with the appearance of through holes. The reason for the appearance of such a defect may be the wrong choice of consumables and operating mode.
- The melt of the roller, its uneven distribution over the surface can lead to a decrease in strength and tightness. The process of cooking thin metal leads to the formation of a welding bath, a molten alloy appears, which falls to the other side under gravity. Due to this, the quality of the connection is significantly reduced.
- Non-welding is obtained when the welder is in a hurry in order to avoid the appearance of other defects. Due to such a defect, the strength of the joint is significantly reduced, the tightness drops. As in many other cases, in this case, the problem can be solved by choosing the correct operating mode of the inverter and the electrodes.
- Surface deformation: Due to the small thickness of the sheets, they begin to overheat quickly, due to which a change in the crystal lattice occurs. This situation causes the sheet to be pulled. That is why welding a thin metal with an electrode does not lead to a high-quality product, if the problem with such deformation of the workpiece is not solved. In some cases, it is possible to carry out a cold edit when using hammers with a rubber working part, but it will be quite difficult to achieve a high-quality result.
All of the above problems can lead to serious consequences. That is why the welder must work out his skills on less responsible products.
Techniques and methods of welding thin metal sheets
Welding of thin metal with an electrode can be carried out using various technologies. In most cases, they will eliminate the possibility of burnout, that is, prolonged exposure to high temperature at one point. Sheet metal welding can be carried out as follows:
- If the thickness of the material is too small, cooking should be carried out in small sections. In addition, welding can be carried out in a staggered manner. The use of such technology allows you to evenly distribute heat.
- In order to avoid the failure of the welding seam, a special substrate is used. It should be borne in mind that metal cannot be used in its quality, since it is welded.
- It is possible to raise the current strength only when using an intermittent arc. Due to the pulse action, the possibility of overheating of the thin material can be avoided.
- The current strength indicator should be 30 A and no more.
Welding of thin sheets of metal should be carried out only after the technology has been tested and honed on various workpieces. Only after that you can start doing the work.
Most of the difficulties arise in the case when the welding of sheet metal should be carried out in the case when the material is galvanized. Alloying substances significantly change the main characteristics of the alloy. Among the features of working with thin material, the following points can be noted:
- When welding, you should initially remove the zinc layer on the edges. This can be done by using an abrasive.
- In some cases, the galvanized layer is removed by burning with a welding machine.
- The work in question should be carried out exclusively on the street or in a room with an effective hood. This recommendation can be attributed to the fact that various toxins can form due to exposure to high temperature.
Welding of thin metal with an inverter in the case when the surface is coated with zinc should also be carried out when choosing a low current strength. In addition, attention is paid to choosing a more suitable inverter.
It is possible to weld thin ones using a variety of technologies, all of them will eliminate the possibility of prolonged exposure to high temperature in one area. If it is necessary to weld galvanized thin metal, then it will have to be pre-cleaned.
Electrodes for welding thin metal should be chosen with extreme caution. This is due to the fact that even the smallest deviation from the established norms leads to the appearance of serious defects. When considering which electrode to cook metal 2 mm, we note the following points:
- When choosing low current values, the most suitable electrodes can be called versions with a diameter of 2 to 3 mm. This is due to the fact that too large an indicator leads to arc attenuation.
- The optimal temperature indicator in the welding zone can be called 170 degrees Celsius. This is quite enough for piercing steel, but its structure is not transformed. Due to this effect, the coating begins to melt evenly, the welder can change the shape of the seam.
- In most cases, an electrode that has a high-quality coating is used. Often, the technology used involves the use of a loose arc, due to which the welding bath has a small size.
Welding of thin metal with an inverter can only take place when using special electrodes that can stabilize the arc.
Selection of modes and electrodes
Experienced welders not only know how to work properly with thin metal, but also choose the right modes and electrodes. The features of this moment are the following:
- A high current strength leads to an increase in temperature in the arc contact zone with the treated surface, resulting in a burn.
- Too low an indicator leads to the fact that the arc is poorly formed. Therefore, the work is difficult.
- Bad electrodes can also lead to a large number of defects of various types.
Only with the right choice of operating modes and suitable electrodes can the possibility of deformation of a thin metal under the influence of high temperature be eliminated.
Machine modes and welding parameters
Experienced welders know which settings of the device allow you to achieve the desired result. By trial and error, the most optimal parameters were derived. All of them are specified in a specific table. Other features of this issue include the following points:
- The current strength should be less than when working with thick metal.
- Inverters that can operate at alternating voltage are excellent. In addition, a high current frequency is selected.
- If the equipment used allows you to set the starting value, then it should be 20% less. This is due to the fact that when the device is started, thin metal is often burned. If there is no such mode, then you can ignite the electrode on a thick material, and then switch to the required one.
- Small currents allow you to avoid quite a lot of problems. An example is the choice of a value from 10 to 30 A.
In addition, a pulse mode can be used. It forms an intermittent arc, as the device itself regulates its supply. By interrupting welding, the heating temperature can be reduced.
Attention is also paid to the welding technique used. Modern welding equipment allows you to set the required parameters for working with thin metal of various types. Among the features of the work carried out, we note the following points:
- It is necessary to correctly bring the edges of the connected elements.
- Often the joint is made by burning through. This technology is suitable for experienced users.
- If possible, the plates are placed overlapping. In this case, the possibility of burnout is excluded. It is recommended to contact the electrode with the lower product, thereby improving the quality of the connection.
There are several common welding methods. An example is:
- At low amperage, the rod is moved strictly along the seam.
- When the indicator increases, the processing is carried out in an intermittent arc.
- To reduce the probability of deformation of the seam, welding is carried out in a staggered manner.
In some cases, a substrate can be used, which also reduces the likelihood of burning through thin metal. Reducing the arc length reduces the likelihood of overheating of the treated area. The electrode should be held at an angle of 45 degrees.
Problems of welding thin-walled products
It is not recommended to carry out such work in the absence of the required skills. The most common problems can be called:
- Formation of a strong influx. The welding bath can blur and even fall through. Therefore, a lot of attention is paid to such a moment.
- The burning of thin material occurs with strong point heating. As a rule, a similar problem arises if a high current value is selected.
- The appearance of a low-quality roller. Controlling a short arc is quite difficult, as is the spread of molten material.
- If the distance between the product and the rod is large, then this can lead to the formation of a long arc. It is characterized by a higher exposure temperature in the melting zone.
We note that the main problems can be avoided by gaining experience, using a modern device and a more suitable electrode. This is due to the fact that new inverters allow you to set optimal current values. In addition, high-quality electrodes form a stable arc even at low amperage. Therefore, you should not skimp on the purchase of consumables, because otherwise it will be quite difficult to get a high-quality seam.