How to properly weld metal with an inverter welding machine. How to weld correctly: basics, technology, choice of current, manual arc welding technique How to weld metal with an electrode

In everyday life in your own home, at your dacha or in your garage, there are always many tasks that require the skills of a welder. This skill is especially useful in DIY construction. In nature, there is no more reliable way to connect two metal parts than welding. And it is quite possible to learn this skill on your own and put the acquired skill to good use. Today we’ll figure out how to learn how to cook with electric welding and independently master the basics of this specialty.

To understand how to properly weld using electric welding, you first need to familiarize yourself with the theory of the welding process.

Connecting metal parts into a monolith using welding is by far the most reliable and durable method. This is achieved by obtaining high temperature. The vast majority of welding machines use an electric arc to melt metals: this is the so-called electric arc welding of metals. At the point of impact, it heats the metal to its melting temperature and does this in a limited area.

The appearance of an electric arc occurs due to current - direct or alternating. The first is typical for inverter welding units, the second – for transformers. Let's take a closer look at them.

The transformer greatly complicates the welding process. Due to alternating current, the welding arc constantly jumps, and the welding process is quite noisy. Another significant disadvantage of such devices is the strong impact on the electrical network, which results in voltage surges;
The inverter is simpler and quieter to operate, powered by 220V. Because of the constant current, the arc is easier to control and move. If there is a need to learn how to cook with electric welding, then it is better to take lesson No. 1 on an inverter machine.

The formation of an electric arc becomes possible when there are two elements that conduct current and have opposite charges. When welding, it is metal and electrode. It makes sense for a novice welder to use a traditional electrode with a metal central element.

To understand how to properly weld metal, you need to clearly understand the processes taking place:

An electric arc appears at the moment of contact between a metal part and an electrode;
At the point where the arc is formed, the metal being welded melts;
Together with the metal, the electrode itself is melted, its molten particles move into the weld pool;
The protective coating that covers the electrode rod also burns and forms a gas cloud. It protects the bath from exposure to oxygen. This ensures that the melting temperature of the metal is maintained at the welding site;
The slag formed during welding also helps maintain the temperature. It is necessary to ensure that the slag encloses the weld pool;
A seam during welding is formed at the moment of movement of the electrode and movement of the bath;
When the metal cools after welding, a slag crust remains on it. It is beaten with a hammer.

This is the theory of welding. It is impossible to understand how to weld metal correctly without experience, so let’s turn to practice.

Preparing the tools

Before electric welding, you need to prepare all the tools and uniforms for protection:

Welding machine and electrodes for it. We recommend stocking up on enough electrodes for practice. The proverb “the first pancake is lumpy” in the field of welding training works without exception;
Protection: welding mask, protective clothing and gloves made of thick materials. Protection should not be neglected during welding work. It's a matter of health and safety!
Auxiliary tools - a hammer and a metal brush - to remove weld slag;
Object for training – metal elements;
Bucket with water. Literally, just in case of fire.

The choice of electrodes is made in accordance with the thickness of the metal being welded, and the setting of the current depends on the electrode. 1 mm of electrode takes about 30-40 A, it is important not to exceed these values, otherwise the arc will not cook, but cut metal.

Let's start welding

So, let’s figure out step by step how to properly weld metal. Probably, to obtain an acceptable result, you will have to repeat this algorithm more than once. But once you learn, you will quickly get used to the role of a welder and will be able to perform quite complex operations.

First of all, we place the electrode in a special holder. Now you need to light the arc. The electrode should be held at an angle of approximately 70° to the surface; this position is optimal.

Having set the angle between the electrode and the metal, draw a quick line, moving about 10 cm per second. If the position is correct, sparks and crackling sounds will appear - this is a sure sign.
Having left the optimal angle of inclination of the electrode, you need to touch the metal with it and immediately raise the electrode so that a track of 3-5 mm is formed. If everything is done correctly, the arc will burn and the metal will begin to melt.
It is not uncommon for the electrode to stick to the base. In this case, you need to slightly swing it and tear it off, and then ignite the arc again. Frequent sticking of the electrode may indicate too low current strength. Try increasing it and compare the results.
Once ignition of the arc and its holding in a stable state are mastered, you can begin to deposit the bead. The clamped arc moves smoothly along the weld. At the same time, movements are made that seem to rake in the molten metal. This is achieved by uniform oscillatory movements with an amplitude of about 2-3 mm. The more measured the movement, the more beautiful the welded seam will turn out. By the way, the uniformity of the seam indicates its high quality and strength.

At the first stage, it is best to train on a thick piece of metal and try to draw various paths with an arc - from simple measured movements with a small amplitude to more complex and patterned seams. These skills will be useful in subsequent work and will allow you to get a good feel for how to cook and what angle of the electrode is best to choose.

After finishing welding, you must wait until the metal cools down. The weld will be covered by slag. To make it fly off, just tap the part with a hammer or run a brush over the iron.

Some aspects of welding work

Of course, welding does not involve writing intricate patterns on a piece of metal. All of the above is just preparation and training for this rather difficult craft. The main purpose of welding is to reliably fasten metal elements and you should strive for it in your training.

Welding metal elements has many nuances, familiarity and understanding of which will come with experience. But there are some theoretical points that you need to know before practice:

It is incorrect to connect two parts at once with a continuous and long seam. In most cases, this distorts the metal, as the seam begins to pull the elements together;
Before making the main seam, you need to tack the parts together. To do this, small spot seams are made at the joints of two parts in increments of 8-25 cm, depending on the size of the elements being fastened.
It is better to make fastening seams on both sides of the welding surface, this way the possible stress on the metal is minimized.
After completing the tacks, the main seam is made.

Let's sum it up

Welding work requires special knowledge, skills and special equipment. Please note that this is a rather complex and dangerous process that requires strict adherence to safety precautions.

Welding skills require some time and practice. There is nothing wrong with training on a piece of unnecessary metal. This allows you to gain experience and understand the essence of the welding process.

Before you start welding parts, you should hone your use of a welding machine and the ability to weld seams on workpieces and then move on to more complex elements.

When drawing up a program for training welders, educational institutions must rely on the following regulatory framework:

Federal Law of December 29, 2012 No. 273-FZ “On Education in the Russian Federation”.
Federal State Educational Standard of Secondary Vocational Education(initial vocational education) in specialty 150415 Welding production (Appendix No. 11.1).
The procedure for organizing and carrying out educational activities in secondary vocational education programs(Order of the Ministry of Education and Science of the Russian Federation dated June 14, 2013 No. 464).
The procedure for admission to training in secondary vocational education programs(Order of the Ministry of Education and Science of the Russian Federation dated January 23, 2014 No. 36).
Regulations on the practice of students those mastering basic professional educational programs of secondary vocational education (Order of the Ministry of Education and Science of the Russian Federation dated July 18, 2013 No. 291);
The procedure for conducting state final certification of secondary vocational education programs(Order of the Ministry of Education and Science of the Russian Federation dated August 16, 2013 No. 968).

Various universities, colleges and training centers provide the opportunity to obtain a diploma or certificate of completion of a course confirming the specialty “Welder”. Depending on which welding technique and which ones will be used, the future specialization of the welder is chosen. There are the following types of welding:

Manual (electric welder). An arc is used that burns between a coated electrode and a weld pool. This technique is widely used in the automotive industry and in the construction of oil and gas pipelines, which require numerous welding of metals in different spatial positions.
MIG/MAG welding is an arc welding process in which a consumable metal electrode is fed into an arc. The workpiece to be welded and the electrode wire melt, forming a weld pool. The shielding gas supplied through the torch nozzle protects the crystallizing seam from air. The gas can be in an inert (MIG) or active (MAG) state.
Welding (TIG)– a refractory tungsten electrode with a high melting point is used. This allows you to weld non-ferrous metals, stainless and low-alloy steels, which can oxidize if not processed correctly.
Plasma welding is a welding process that takes place in a liquid state in which metal plates are joined while in a. Plasma itself is an ionized gas containing neutral and electrically charged atoms. The temperature limit of this technique reaches 30,000 °C.
When welding, a laser is used as an energy source. This technique is used when components need to be welded together using small welds. High welding speed, automatic mode and the ability to control quality interactively during the manufacturing process make laser welding a widespread method in modern industrial production.
(gas welder, gas-electric welder)– a metal welding process in which the melting of the materials being joined forms a homogeneous structure. Gas combustion occurs due to the introduction of pure oxygen or acetylene into the gas mixture.

These methods are introduced in educational institutions. The future welder decides which one he will specialize in.

In the future, he has the right to apply to improve his qualifications, as a result of which the scope of his capabilities will expand, and his demand in the labor market will increase.

Features of the training program

The training program for welders is compiled on the basis of Federal State Educational Standards NPO No. 50 for the profession “Welder”. In educational institutions, it is mandatory to study the basics of engineering graphics and the basics of materials science. The future specialist gets acquainted with the electrical engineering used during welding work. Due to the specifics of this profession, special attention is paid to the basics of life safety. A student takes a course in economics. After graduation, the young specialist will have experience in welding and cutting parts from various metals and alloys, and will learn to bear responsibility for the work performed.

If you have a certificate of basic general education, you need to study for another 3-4 years, depending on the institution where teaching is carried out, and if you have a certificate of secondary general education - from 2 to 3 years.

Knowledge of how to weld using electric welding correctly, in compliance with technology, will allow you to independently create various types of metal structures and products. If you have no experience, you can easily master the basics and techniques, and then successfully apply them in practice.

Electric welding

To understand the basics of electric welding, you need to understand the essence of the process itself. The joining of metal elements occurs as a result of local expansion under the influence of high temperatures. An arc is created that melts the metal, then the finished structure cools down and becomes strong and solid.

There are two ways to create an arc:

on direct current;
on alternating current.

Inverters are used for DC welding. They create an arc with stable electrical parameters, which simplifies the welding process:

an even, uniform seam is formed;
metal does not spatter.

Many inverters have standard presets equipped with protective functions that allow you to monitor the current parameters. They can be used by beginners or professionals.

For welding on alternating current it is necessary to use transformers. Their advantages: high power, unpretentiousness to network parameters. But at the same time they have a lot of weight and a high noise level. In addition, they can cause interference in electrical networks.

Tools

Welding will require the selection of special equipment:

a welding machine suitable for the technical characteristics;
electrodes of a certain composition, depending on the type of metals being connected and their thickness;
protective mask, clothing, gloves, shoes;
hammer, metal brush to remove scale or smooth seams;
containers with water.

Beginners need to take elements of similar composition and thickness to select current and voltage. It is also recommended to practice creating seams with the required characteristics so as not to damage the workpiece.

The welding site must comply with the rules and safety requirements. The area of the room or area should be sufficient for the convenience of performing the work.

In case of problems with the power supply, you will need to additionally connect a rectifier. This will stabilize the current and voltage, thereby forming a stable arc.

Which electrodes to use

Electric welding for beginners is a complex process if the electrode was chosen incorrectly. The quality of the seam, uniformity, meltability, absence of impurities and harmful compounds depends on its properties. Therefore, the following selection criteria are taken into account:

the rod must have the composition as close as possible to the metals being welded;
the protective shell must protect the seam from the formation of oxides;
The connection polarity should be observed depending on the marking;
current parameters must meet the requirements of the welding machine and the thickness of the parts;
the diameter must be selected so that a seam with the required characteristics can be formed.

Pack of electrodes

How to learn to cook with electric welding

To learn electric welding, you need to prepare a workplace, collect all the tools, and ensure work safety. If you master all the stages on your own, then you will need to find materials to hone your skills.

It is important for a novice welder to learn how to properly equip a work area:

install protective screens;
remove flammable or combustible materials;
provide access to tools.

You need to choose clothes, since it is extremely inconvenient to weld metal correctly using electric welding with a feeling of discomfort:

clothing should be made of thick fabrics;
Shoes with nailed heels are not acceptable;
the welding helmet must have glass with dimming adjustment;
It is recommended to use split leather gloves.

It is required to follow the rules of metal welding:

the surfaces of the parts must be cleaned from scale, rust, and dirt;
the welding machine should be grounded;
when working, you must comply with safety requirements;
follow the rules of the selected welding technique.

How to connect the electrode

The connection is made to a special clamp located at one end of the cables. There are two types of locking mechanisms:

screw, which is a rotating clamp with a clamp;
spring, allowing you to fix it when you press a special button.

When using an inverter, the ground cable is connected to the positive terminal, and with a clamp - to the negative terminal. When argon welding, the polarity is changed.

Start of welding: light the arc

You can ignite an arc in the following ways:

tapping - the end hits the surface of the part several times;
conducting - an electrode is quickly drawn along the seam line.

It is important to test these methods in advance and choose the best one for solving specific problems.

Convenient angles of inclination of electrodes above the surface of the parts being welded are considered to be from 30 0 to 60 0. The angle can be formed in the following ways:

forward, allowing minimal heating of the metal;
back, the parts are heated to the maximum depth for the selected current, the slag moves at the speed of closing the weld pool.

To fully control the process, it is necessary to maintain a distance from the surface to the electrode of 2 to 3 mm.

Welding tilt

Movements

When moving the electrode, it is important to consider the following criteria:

you should think in advance about the optimal movement pattern along the surface in order to obtain a seam with the desired characteristics;
the speed of movement determines to what depth the metal will be melted;
the formation of the seam must be carefully controlled during the work process;
it is important not to allow the electrode to approach the surface of the element closer than 2 mm;
movement should be carried out only after the formation of the bath.

What errors might there be?

When carrying out welding work with their own hands, beginners can make the following mistakes:

the operating mode of the welding machine is incorrectly selected;
the melt in the bath is not formed with the structure required;
the current strength does not correspond to the metal or its thickness, resulting in penetrations or unwelded areas;
the polarity of connecting the mass and electrode cables is incorrectly selected;
the welding machine is powered from an unstable network, as a result of which it may fail and require expensive repairs;
welds are formed without sticking, due to which the joining of structural elements is not carried out in accordance with the assembly requirements;
parts are connected without stripping to bare metal;
fire safety measures are not observed.

Metal structures are connected in two ways: detachable - using screw fasteners, and permanently - using welding. The second method is more reliable and durable; it is often preferred to the first when there is no need to disassemble the structure. In your own home, especially one still under construction or improving, the need for welding work often arises, so many would like to know how to properly weld metal themselves, so as not to look for a specialist for minor work.

It will take much less time to weld two pipes than to find a welder

Choosing a machine for household welding

There are many types of welding today. But most of them are intended for special work or are designed for industrial scale. For domestic needs, it is unlikely that you will need to master a laser machine or an electron beam gun. And gas welding for beginners is not the best option.

The easiest way to melt metal to connect parts is to pointly influence it with the high temperature of an electric arc that occurs between elements with different charges.

It is this process that is provided by electric arc welding machines operating on direct or alternating current:

The welding transformer welds with alternating current. For a beginner, such a device is unlikely to be suitable, since it is more difficult to work with due to the “jumping” arc, which requires considerable experience to control. Other disadvantages of transformers include a negative impact on the network (causes voltage surges that can lead to breakdown of household appliances), loud noise during operation, impressive dimensions of the device and heavy weight.

An inverter has many advantages over a transformer. It generates an electric arc with direct current, it does not “jump”, so the welding process is more calm and controlled for the welder and without consequences for home appliances. In addition, inverters are compact, lightweight and virtually silent.

Therefore, if you are faced with the task of learning how to cook with electric welding, then it is best to purchase an inverter machine.

What else do you need to have?

A welding machine without electrodes is a completely useless unit. Electrodes are a consumable material, they also come in different types: melting and non-melting, metal (made of steel, copper and other metals) and non-metallic, in the form of wire or a rigid rod, with different protective coatings, etc.

For those who are wondering how to properly weld with electrodes, it is best to start with steel universal rods 3 mm or 4 mm thick. The diameter is indicated on the package, it will not be difficult to choose the ones you need. Having mastered working with them, you can switch to other types, but they are unlikely to be in demand in everyday life.

In addition to welding consumables, you will definitely need a welder's mask. It is absolutely impossible to work without it, otherwise you can quickly get a burn to the cornea and many other vision problems. Masks with chameleon glass are considered the best. Or rather, with an automatic light filter that reacts to changes in illumination and protects the eyes from harmful radiation.

It is also advisable to acquire suitable clothing, shoes and gloves that are not burned by sparks and can protect against electric shock if something happens.

The tools you will need are a hammer to knock down scale from the seam, as well as all kinds of vices, clamps and magnetic corners that can be used to fix the parts to be welded in the desired position.

Minimum kit for a beginner welder

Basics of welding work

To cause the formation of an electric arc, two differently charged conductive elements must come into contact. One of them, negative, is the electrode, and the other is the surface to be welded, to which a metal clamp is connected, the cable from which is connected to the positive output of the inverter.

Electrode welding is caused by the melting of the metal by the heat generated by the arc. In order for the seam to be smooth, it should not be interrupted. So, to get started, you need to install the electrode, configure the inverter, light the arc and learn how to control it.

Electrode installation

The inverter device is equipped with two cables. A clothespin clip is attached to the end of one of them, with which it clings to a metal part. And the second cable is equipped with an electrode holder, which can be screw or spring.

For the screw holder, you need to unscrew the head on the handle, and after installing the electrode in the socket, screw it back in. With a spring one it’s easier: just press the key to open the socket.

Connecting the welding machine

Welding cables are connected to the inverter through special outputs on the device body with different polarities. Which of them to attach the clamp to, and which electrode, depends primarily on the materials being welded. You need to understand this point in order to understand how to weld correctly and not get confused:

The standard connection for welding steel parts is a minus to the ground cable with an electrode, and a plus to the cable with a clamp. It is called direct polarity and is suitable for most connections required in everyday life. Direct polarity ensures the classical movement of electrons from minus to plus, in which they transfer a significant part of the energy to the metal and heat it better.
If you connect the clamp to minus and the electrode to plus, we get reverse polarity with a lower degree of heating. What is necessary when welding stainless steel products and in some other cases.

Advice! It is best to master the basics of welding on parts made of ferrous metal, using a connection with straight polarity.

Now you can plug the device into the network and get to work.

Ignition of the electric arc

Before learning how to weld, you need to cause an arc to appear, for which you make short-term contact of the electrode with the metal part. This can be done in two ways: end-to-end and by striking:

Butt ignition involves tapping the metal with the tip of the connected electrode.
Ignition of the arc by striking is performed in the same way as lighting a match on a box.

There are no advantages to any of these methods - everyone does what he likes and is most comfortable with.

Video description

The methods for igniting electrodes are clearly shown in the video:

The main thing is that the movements are fast enough and the contact is short-lived, otherwise the electrode will “stick” to the metal. This happens especially often with new electrodes that have not yet been used.

At the same time, a partially spent electrode may not ignite immediately due to the buildup of the melted protective coating formed at its tip. It is easier to beat it off using the tapping method.

You can proceed directly to how to properly weld with electric welding after confidently mastering the skill of exciting an arc. But first, it’s worth understanding what is happening or should happen in the process. Without this it will not be possible to move on.

Welding process analysis

At the point where the welding arc occurs, the temperature rises greatly, as a result of which the metal of both the parts being welded and the electrode rod itself begins to melt. Liquid molten metal fills a burned-out depression, which in professional language is called a weld pool.

Schematic illustration of the electric arc welding process

At the same time, the protective coating of the electrode is destroyed, fulfilling its function: part of the coating melts, turning into slag, which covers the fresh joint and prevents the metal from contacting oxygen, and also maintains a high temperature underneath. And the other part goes into a gaseous state, creating a protective atmosphere around the weld pool, and also preventing air oxygen from reaching it.

Video description

All this can be clearly seen in slow motion:

The slag crust from the weld is knocked off with a hammer after it has cooled.

Important nuances

The main secret of how to properly weld two parts and get an even seam is that when moving the electrode, the slag has time to cover the entire surface of the molten metal. And this depends on the speed of movement, the angle of inclination of the electrode and the trajectory of its movement. The current strength is also important.

The universal working angle is 30-60 degrees relative to the vertical. Wherein:

moving the electrode at an angle forward (away from you), it is convenient to make any vertical, horizontal and circular seams;
at an angle back (towards you) - weld corner joints;
the vertical position of the electrode is allowed only when welding in hard-to-reach places;
An angle of more than 60 degrees greatly stretches the weld pool, and the metal of the welded parts heats up worse. It is usually used when you need to trim off excess or touch up a rough seam.

The welding speed is determined experimentally: it is necessary to ensure that the shape and dimensions of the weld pool remain stable and do not stretch or spread. It is very important to keep the electrode at the same distance from the surface - 3-5 mm from it. Moreover, as the bath is burned out and deepened, it must be lowered slightly, and when moving to the next section, raised again, trying not to go beyond the specified limits.

To connect the edges of two parts, you need to ensure that their particles penetrate each other. To do this, the electrode must move not in a straight line, but along a certain trajectory, oscillating from side to side. This trajectory may resemble a herringbone, ladder, figure eights, connected triangles, etc.

The result should be an even bead of deposited metal with the same height and width along its entire length. To achieve this, you need to practice a lot, practicing movements and adjusting the strength of the current. Because there is a difference in how to weld thin sheets, thick-walled pipes or other products.

Initially, it is selected according to the table and depends on the thickness of the parts being welded.

These are approximate values and are based on welding with the electrode pointing downwards. When making vertical or ceiling seams, the current strength is reduced by 10-20%.

Note! The thinner the edge being welded, the smaller the diameter of the electrodes, and vice versa. “Troika” is suitable for materials with the most common thickness from 2 to 5 mm.

But during voltage surges in the network, the set current strength may not be enough for the normal flow of the process in the operating mode. Then you have to reduce the speed of movement of the electrode or use a different trajectory of movement in order to pass through one place more than once.

All this is quite difficult to describe in words - you need to try and achieve satisfactory results.

Video description

This training video will help you a lot:

Advice! It is best to learn to cook not at the joints, but on a plane, practicing speed, trajectory, level and angle of inclination. An imaginary joint on a metal plate can be drawn with chalk and a weld bead placed along it until it turns out well.

Welding of elements

Having confidently mastered the basics of the welding process, you can move on to connecting elements into a single structure. And here, too, there are subtleties associated with the reaction of the metal to such an impact.

First of all, you need to correctly assess the length of the seam and ensure that it does not pull the parts being connected at the joints. To do this, they must be fixed in a given position using clamps or other methods. And to secure the fixation, they are secured with transverse seams in several places. And only then are they scalded.

The welding order depends on the length of the joint. Only short seams up to 300 mm long can be welded in one direction and in one pass. If this distance is greater, it is necessary to compensate for the resulting stresses by applying stitches in small sections.

Seam patterns depending on length

When the work is finished, not very beautiful seams can be carefully cut off and sanded with a grinder.

Conclusion

Now you have an idea of how to learn how to weld by yourself. But in this matter, knowing the theory means knowing practically nothing. You need practice, perfecting the movements until they become automatic, and most importantly, developing a special instinct that will tell you when to lower the electrode a little lower, when to change its angle or increase the current strength. All this comes with time. But you need to be prepared for the fact that at least one pack of electrodes will be spent on training.

Many structures are made from thin steel. These are car bodies, containers for liquids, and small diameter pipes. At enterprises, welding of thin sheets of metal is carried out with special machines that ensure optimal connection. But how to weld such materials at home? What electrodes are suitable? What machine modes should you use to stitch? Welding thin metal with an inverter will be successful if you know the answers to these questions and also watch the corresponding video.

Not all welders can weld steel sheets 1-1.5 mm thick. This requires certain knowledge and skills. But if you show persistence and practice, and also study a video on how to weld thin metal with an inverter, you can achieve significant success.

Welding thin metal is complicated by the following factors:

Burns. Since the material being welded is quite thin, through holes often occur in it. This is the most common mistake made by beginner welders. The reason is the incorrectly selected current strength and slow welding.
Lack of penetration. Wanting to avoid the first defect, welders are too hasty when passing the joint, and unwelded areas remain. This spoils the tightness of the connection and makes the product unsuitable for working with liquids. The resistance to breaking and breaking is also low. The correct settings of the inverter and the choice of electrodes help in solving the situation.
Sagging on the reverse side. Welding thin sheet metal is accompanied by another common problem - protruding beads on the back of the surface. From the front part, the product has an even seam, without pores or lack of fusion, but the molten metal of the weld pool, under the influence of gravity, pushes the seam section to the other side. The situation can be solved by using special substrates or reducing the current strength, and changing the suture technique.
Structural deformation. Sheet steel quickly overheats, which leads to expansion of the intermolecular component. The structure begins to stretch in the heating zone. Since the edges of the product remain cold, the surface becomes covered with waves or a general bend. On non-critical products, cold straightening of the mold with rubber hammers is possible. But if this is not possible, then a certain alternation of suture application along the entire length is used.

Electrodes used

To successfully cope with such work, it is important to choose the right electrodes for thin metal. Since welding is carried out at low currents, the use of electrodes with a diameter of 4 and 5 mm will “strangle” the electric arc, preventing it from burning normally.

The best option for connecting thin metals are electrodes with a diameter of 2-3 mm. Arc welding will be successful if the consumables are pre-heated at a temperature of 170 degrees. This will allow the coating to melt evenly without interfering with arc manipulation and weld formation.

Electrodes for welding thin metal must have a high-quality coating. The technology for working with sheet steel involves an intermittent arc, for which the electrode is briefly detached from the weld pool. If the coating is refractory, the result will be the formation of a kind of “visor” at the end of the electrode, which interferes with contact with the surface and resumption of the arc.

Machine modes and welding parameters

Experienced welders know how to weld thin metal by testing a variety of machine settings. As a result, optimal parameters were derived that are well suited for this type of work. Here are the main settings:

It is important to set the welding current lower than when working with thick plates. This will help avoid burns and leaks. Inverters that allow cooking with alternating voltage but at high frequencies, as well as direct current devices, have proven themselves to be excellent in this area.

If the unit settings allow you to set the starting voltage level, then you should take advantage of this and set a lower value (by about 20%) than the operating current. This will prevent the area from being scorched when starting to ignite the arc and will help to start welding immediately at the joint. If the starting current is not regulated, then you can ignite the electrode on a thick surface and then transfer it to the joint.

Welding thin metal involves working at low currents. To do this, the inverter settings must maintain the operating values of the ammeter at the level of 10-30 A. If the minimum adjustable value is higher than these parameters, then it is possible to reduce the current strength with additional resistance in the circuit. For this, a high-carbon steel spring is used, placed between the product and the ground cable. Installing an additional ballast that reduces the current to the required level will also help.

If the device settings support the pulse mode, then you can use this. Especially thin steel is welded with an intermittent arc. The pulsed current will automatically break the arc, allowing the metal to cool.

Welding technique

Welding thin-sheet iron requires proper approach of the edges of the plates to each other. Butt joints often result in burn-throughs and are only suitable for experienced welders. If possible, it is worth placing the plates overlapping. This will create some basis for the deposited metal, and will not allow burning through the entire product. In this case, the electrode is directed primarily to the bottom plate, since a different position will lead to undercuts on the top side.

When joining into a butt, the edges are not cut. There is no need for a gap either. It is necessary to bring the ends of the parts together as tightly as possible and tack. Low current strength and thin electrodes make the work much easier. You can then cook it in several ways:

Set the current to low and quickly sew the seam without oscillatory movements, strictly along the connection line.
Raise the current a little higher, but conduct the seam with an intermittent arc, giving the metal time to cool before the next “portion” of the additive.
Cook using the methods described above, but using a special substrate to maintain a heated area and avoid sagging. A metal table will not work here, since the product may be partially welded to it. A good alternative would be a graphite backing.
To prevent severe deformation, apply stitches in a checkerboard pattern, or in small sections (100 mm each). With the latter method, it is necessary to finish the next seam at the beginning of the previous one. This will allow the product to be heated evenly along its entire length and minimize deformation.

Welding is carried out with a short arc, which allows you to quickly form a seam and avoid overheating of the area. Increasing the distance between the end of the electrode and the surface visually prevents burning of the plates, but does not contribute to the formation of a welding bead. The electrode is held towards itself at an angle of 45 degrees, or tilted to the side. Right angles should be avoided as this leads to burns.

Alternative Methods

In addition to inverters, a semi-automatic welding method is also well suited, especially when working with car bodies. The advantage is that there is no need to change the electrode, since the wire is fed continuously. This significantly speeds up the entire process for large projects. The distance between the product and the heating pad is easier to control since there is no combustible part of the electrode. This method is easier for beginner welders to master.

Semi-automatic welding allows you to work with even thinner sheets of steel due to the use of 0.8 mm wire. But such equipment is not always available in everyday life, so the inverter method remains in demand. After considering these tips, it becomes clear how to properly weld thin metal. Additional videos about working with an inverter and semi-automatic machine will help you consolidate your knowledge and start practicing.