Welding work with an inverter for beginners. How to cook with inverter welding: tips for beginners

Welding is one of the rather complex, but highly demanded technologies for working with metals. Wherever you look, welded joints are necessarily used. Not a single industrial production, construction company, repair or service company can do without this process. Welding becomes indispensable in the construction and improvement of one's own home.

But here's the problem - welding requires a certain degree of preparedness. You can, of course, if necessary, contact the master welders for ads, or to your friends who have the necessary skills. But it’s better to ask yourself the question - how to learn how to work with electric welding on your own, so as not to be dependent on anyone. Today, when home welding equipment has ceased to be a problem, the ability to carry out such work, especially for the owner of individual housing, is an invaluable plus, since many problems simply cease to exist.

But first of all, you need to understand the basic concepts of electric welding and purchase equipment. Welding is technological process where the quality of work directly depends on the equipment of the workplace.

The very essence of electric welding is as follows. The power plant generates a powerful welding current, which is supplied to the work station through cables. An electric welding arc is created between the electrode and the surface of the metal to be welded - a stable discharge, characterized by the highest temperature values. This leads to melting of the metal and filler material. A so-called weld pool is formed - an area of ​​the melt, controlling and directing which the welder forms a seam. After the arc is removed, the molten metal crystallizes and a strong monolithic connection of parts is created.

This very simplified scheme is implemented in several welding technologies:

• most widespread is manual arc welding, which, according to existing terminology, has the abbreviation MMA (from English name « Manual Metal Arc»). main feature- the use of fusible electrodes with a special coating. Advantages - no particularly complex technical support, gas-balloon equipment is required. The disadvantage is the possibility of welding only with ferrous metals or stainless steel.

In the vast majority of cases, if welding is considered at the household level, then this technology is meant.

• TIG welding technology allows you to work with alloyed steels and some non-ferrous metals. The term " Tungsten Inert Gas speaks for itself: tungsten and inert gas. In this case, the arc is created between the surface to be welded and the infusible tungsten electrode, and a filler rod of one type or another is introduced as a filling. At the same time, a protective inert gas is constantly supplied through the welding torch with a heat-resistant ceramic nozzle, which ensures the cleanliness of the seam.

Welding according to this technology has a lot of advantages, but it requires special equipment and highly skilled workers.

Metal Inert Gas - Metal Active Gas) is one of the most advanced modern technologies, which is increasingly used by home craftsmen. The cooking process also takes place in an environment of inert or active gases with automatic feeding filler material (welding wire) which plays the role of an electrode.

This technology makes it possible to produce high quality seams in any plane and with very high productivity. To some extent, it is even simpler than M MA, but requires complex and rather bulky equipment - the welding machine itself, the wire feeder, the gas-balloon device, the burner with a special sleeve through which the wire and shielding gas are poured.

• There is also spot electric welding - SPOT, which finds the widest application, in particular, in the body sections of car service enterprises. It will also require special sophisticated equipment, and is practically not used at home.

Manual arc welding MMA - what is required for work?

Any beginner always starts by mastering the techniques of manual arc welding (MMA), so all the questions discussed below will be devoted specifically to her.

To start practicing on your own, you need to prepare certain equipment, equipment and supplies.

arc welding machine

For welding using MMA technology, one of three types of devices is used:

• A welding transformer is one of the simplest types of equipment. The principle of operation is elementary - the mains voltage of 220 V (or 380, for a three-phase network) is converted to a lower one, of the order of 25 - 50 V, but due to this, the value of the current increases sharply. The advantages of such a circuit are its simplicity, high reliability and ease of maintenance , high power ratings. Such devices are inexpensive, which, probably, largely determines their prevalence.

The disadvantages of the transformer are much greater - the welding arc from alternating current does not differ in stability, there are frequent cases of sticking of the electrodes, large spatter of metal, the seams are not accurate. In addition, special electrodes will be required specifically for the “change”. Welding transformers are very dependent on the mains voltage, and in the process of operation they themselves can seriously “sag” the network. They do not differ in compactness and lightness. In a word, it is undesirable to start training with such equipment. As a rule, good skills are required to work on such devices.

• Welding MMA rectifiers differ from transformers in that they give a direct current at the output. It is much easier to work with them, as the "permanent" arc is much more stable, and the seams are more accurate.

However, shortcomings remain- the same massiveness and overall dimensions, even more than that of welding transformers, dependence on the supply voltage and a large load on the network. At a price they are more expensive than transformer devices.

• Without exaggeration, we can say that literally a revolution in welding technology was made by devices operating on an inverter circuit. Mains alternating voltage 220 V with a frequency of 50 Hz goes through a whole cascade of frequency and amplitude transformations, and the required direct current with the highest degree of stabilization is obtained at the input. All processes are controlled by a microprocessor assembly, which allows you to make the required adjustments with a high degree of accuracy.

Most modern solution- welding inverter

All this gives a whole "bouquet" of advantages of such a device:

- The equipment calmly tolerates quite serious fluctuations in m = mains voltage, which is especially important in suburban villages, where such problems are a very common occurrence.

- At the same time, inverters, in comparison with other devices, have minimal energy consumption - they practically do not overload the network.

- Stabilized current and the possibility of its fine adjustment allow you to perform accurate and neat seams. There is practically no spatter.

- The device is compact and lightweight.

A wide range of such devices is produced - from household-class inverters to professional equipment. For beginner welders the most optimal solution. Prices for high-quality inverters are quite high, but, firstly, they tend to decrease, and secondly, such a one-time purchase will fully justify itself. And a lot of inexpensive devices of a very dubious assembly appeared on sale. Therefore, it is very important to approach the problem correctly. inverter selection - You need to pay attention to a number of important nuances:

• Maximum welding current. If the device is planned to be used in a household environment, then, as a rule, stop on models with a value of 150 - 200 A. this is quite enough to work with electrodes with diameters up to 4 mm.
• Resistance of the electronic circuit to mains voltage fluctuations. Quality inverters must withstand fluctuations within ± 20 ÷ 25 %.
• The inverter must have a forced cooling system that works constantly when the power is on, or equipped with automatic equipment that starts ventilation at a certain temperature of the radiators.
• We should not forget about the power consumption of the device - it can be on the order of 2 ÷ 3 kW for small models, but can reach even more significant values ​​for devices semi-professional or professional class.
• What about m many simply do not know: the parameter that determines the permissible duration of the welding process is the on-time (ST). No device can work without interruptions, and the parameters must indicate the PV, expressed as a percentage of the total duration of the equipment. For household models, this usually amounts to about 40% - nothing can be done, this is the price for the compactness of the device. In practice, this means that the "rest" period, in this case, is 1.5 times longer than the welding time, for example, 1 minute of continuous work will then require at least a minute and a half pause.
• For novice welders, it will be very convenient if some useful functions are implemented in the apparatus circuit:

- "HotStart" greatly facilitates the initial ignition of the welding arc. The electronics automatically increases the current value at the moment of ignition in impulses.

- "ArcForce" will help to cope with the eternal problem of beginners - sticking of the electrode to the metal surface. With a decrease in the required gap between the electrode and the metal, the current increases, preventing this trouble.

- "AntiStick" - a function that will prevent the machine from overheating if sticking still could not be avoided. In this case, the power will simply turn off automatically.

Another important tip. The "Achilles heel" of inverters is a certain difficulty in carrying out repair work in the event of a circuit failure. When choosing a device, it is better to give preference to models with a multi-board layout of the electronic circuit. Buying such devices is a little more expensive, but the diagnosis of breakdowns becomes easier, maintainability is much higher.

Video: how to choose a welding inverter

Welding leads, electrode holder, ground clamp

Welding inverters, as a rule, are already equipped with wires, an electrode holder and a ground clamp. However, when buying these elements, you should also pay close attention - sometimes you can run into low-quality products.

• Welding wires must be in flexible rubber insulation, have reliable brass contact plugs suitable for the connectors of a particular machine. The cable cross section must be at least 16 mm² if the device is designed for currents up to 150 A, 25 mm² - at 200 A and even 35 mm² if it is supposed to work with currents of 250 A and above. Do not chase long wires or extend them yourself - this can lead to an overload of the electronics and the failure of the inverter.
• Electrode holder - essential element equipment of the welder, since the master manipulates it in the process of work. Do not use homemade "plugs" for work - this is quite dangerous in terms of getting light burns to the eyes or electric shock. by the most widespread and convenient today are pliers-type holders - “clothespins”. Some are convenient, allow easy and quick replacement of the electrode, are well insulated on all sides and provide proper safety.

One of the most common - holders - "clothespins" of the pliers type

The holder must have a reliable clamp for the electrodes, allowing them to be placed not only perpendicularly, but also at an angle of 45 º. It is necessary not to be too lazy and check the material of the contact part - there should be copper or brass, but not copper-plated steel. This is - clear sign cheap counterfeit, which is easy to detect with a small magnet. It is necessary to check the reliability of electrode fixation, especially of small diameter (2 mm) - this is often a problem for low-quality pliers-type holders.

An important factor is the convenience of the holder, its balance, "weight distribution" - working with it should not cause rapid hand fatigue. It should have a handle long enough to allow the most comfortable hand position, a corrugated surface to prevent slipping in a mittened palm. Do not forget that for the holders the maximum value of the welding current is also determined.

• The clamp for connecting the ground must have a powerful spring, a reliable connection to the wire, brass contacts for crimping a metal workpiece, connected by a copper bus.

Welder equipment

• First of all, for welding you will need a mask or shield. Shields often come with inverters, but they have an inconvenience - it must be held with a free hand, and this is far from always possible. It is better to buy a full mask.

This piece of equipment protects the eyes from light burns, covers the face from splashes of metal or sparks, and the respiratory organs, to a certain extent, from rising gases. At the same time, the light filter should provide good visibility of the superimposed seam when the arc is ignited - the selection is made individually. The light filter must be covered with protective glass.

The mask itself is made of heat-resistant plastic. It should not be heavy and bulky, causing rapid fatigue. It is necessary to check the convenience of the headband and its fixation in the desired position, the possibility of adjustment to the required size.

Masks - "chameleons", equipped with special liquid crystal filters that instantly change light transmission at the moment of ignition of the arc. Convenience is undeniable - there is no need to constantly fold back the mask for visual control of the completed seam, and the process of ignition of the arc is also simplified. Such masks have a certain degree of adjustment of the response speed and the degree of dimming - this is another significant advantage. The disadvantage they have is a rather high price.

• For work, you will need special clothes, sewn from their durable dense fabric, which excludes instant melting or burning when sparks hit (e.g. tarpaulin) Patch pockets on a jacket or pants are strictly prohibited.

Shoes should be leather, completely closed, its top should be securely covered with trousers. Hands must be protected with leather or thick canvas mittens or gloves (gaiters) with long cuffs that completely cover the wrist area.

• For the production of welding work, in addition, you will need a special hammer for chipping slag, iron brush for cleaning the surface of the metal. Cutting blanks and cutting parts (chamfering, etc.) will require a “grinder” machine with cutting and grinding wheels.

What electrodes to use?

Electrode represents a steel rod coated with a layer of coating. The rod is both a conductor for the welding current and a filler material. The coating, when exposed to high temperatures, creates a protective layer of slag and gas, which protects the weld from instantaneous oxidation by oxygen and nitrogen in the air.

It is very important to choose the right electrodes

There are situations when the equipment is good, and everything seems to be done according to the rules, but the weld does not work. Perhaps the reason lies in the wrong selection of electrodes. Alas, many novice craftsmen select them, focusing only on the thickness of the rod section, losing sight of the rest of the characteristics. Meanwhile, the classification of electrodes is quite complex and diverse. Of course, you can get advice when buying, unless of course the seller himself understands this. But you can try to deal with some issues on your own.

For example, an electrode E42 A-U OHI-13/45— 3.0-UD (GOST 9966-75) or E-432(5) – B 1 0 (GOST 9967-75). What can numbers and letters tell about?

• E42 A– a special designation that speaks of the mechanical and strength qualities of the created seam. Characteristic more required for engineering calculations.
• UONI -13/45 - the brand of the product is encrypted here. assigned by the manufacturer.
• 3,0 – the diameter of the metal rod is 3 mm.
• Letter "U" indicates that it is intended for welding carbon or low alloy steels - what is most often required at home. You can find designations "L", "T", "V" are electrodes for doped and in instrumental steels of various types, and "N" - to create a surfacing layer on the metal surface.
• Letter "D" in this example, it speaks of a thick coating. The thin layer will be marked "M" , average - "WITH" and very thick "G". Preference should be given to a thick coating.

According to the following GOST, the decoding is as follows:

• E-432(5) - information for specialists on the physical and chemical properties of the deposited additive.

"B" is a coating classification. In the given example, the main one. Besides You can find the following designations:

- "BUT" - acid type coating, suitable for constants, and for change, for any types of seams, but gives strong spatter.

- "B" - the main one, used for welding powerful thick parts using reverse polarity.

- "R" - rutile coating - one of the most common, perfect for a novice welder and for work at home.

- "C" - coating with cellulose component. It is very convenient for large-scale work, but requires special qualifications of the welder, as it does not tolerate overheating.

- "RC", "RTsZh" — combined type. The letter "Zh", in addition, indicates the inclusion of iron powder in the composition. It is mainly used by qualified specialists for a special type of work.

• The next figure indicates the spatial arrangement of the seams that can be performed with this electrode.

— "one" - universal;

- "2" - everything except vertical top down;

— "3" - the "ceiling" and the vertical are unacceptable, just as in clause 2;

- "4" - the electrode can only perform lower seams.

• The last digit of the marking is an index indicating the parameters of the required welding current. The data are summarized in a special table, taking into account both the type of current, and the value of the open-circuit voltage of the device, and the desired polarity. In order not to go into details - just a few words about what needs to be considered. There are ten gradations in total, from «0» before "nine" . For alternating current, any, except «0» . When "permanent", the polarity of the connection will not matter for the indices "1", "4", "7" . electrodes "2", "5" and "eight" - exclusively for direct polarity, and "0", "3", "6" , and "nine" - only for reverse.

The diameter of the electrodes is selected depending on the thickness of the parts to be welded. You can easily focus on the following parameters:

— For blanks up to 2 mm thick — Ø 1.5 ÷ 2.5 mm;

- 3 mm - Ø 3.0;

- 4 ÷ 5 mm - Ø 3.0 ÷ 4.0;

- 6 ÷ 12 mm - Ø 4.0 ÷ 5.0;

- over 12 mm - Ø 5.0.

Video: classification of electrodes for manual arc welding

Workplace preparation

To start practical exercises, you need to prepare yourself a workplace:

• Work best for fresh air and open space - the probability of ignition of building structures is excluded, less exposure to toxic fumes.
• There should be no flammable materials or liquids near the workplace.
• In case of fire, fire extinguishing agents should be prepared - water, a flame-retardant cape made of dense fabric, sand. At the same time, water can be used to extinguish the flame only when the apparatus is completely de-energized.

The optimal solution is a metal welding bench

• It is best to work on a metal workbench. You should consider the issue of fixing workpieces (vices, clamps, etc.). )
• The extension cord must be sized to suit the peak power consumption of the welding machine.
• Before starting work, it is necessary to provide measures to exclude the appearance of strangers, and in particular children.

First practical steps

If everything is ready, you can go to practical action. To begin with, it is best to prepare a sheet of metal, cleaned of dirt and rust - it is better to work out the first steps on it, without rushing to immediately weld any parts.

A mass clamp is attached to the workpiece. Good contact at the junction is very important - it should be cleaned with a metal brushed

It is best to start training with electrodes Ø 3 mm - it is easier to “fill your hand” with them. The value of the welding current in this case will be about 80 - 100 A. The electrode is inserted into the holder, the reliability of its fastening is checked.

• The first "exercise" will be to strike and hold the welding arc. To do this, after turning on the device and lowering the mask, you either need to strike the electrode on the metal surface, or knock several times on one place. A spark must appear, and now the most important thing is to keep the burning arc. To do this, it is necessary to strictly maintain the gap between the electrode and the metal surface. The position of the electrode is approximately 30º from perpendicular to the surface.

A normal gap is considered to be one that is approximately equal to the thickness of the electrode rod - this is called a short arc. When inverter welding using high-quality and dry electrodes, there are usually no problems with arc stability. With an increase in the gap to 4 - 5 mm, a long arc is obtained, which will not give a high-quality seam. Excessive approach of the electrode to the surface may result in its sticking. In this case, you should immediately swing the holder to the side until the rod overheats.

When maintaining the arc, it should be remembered that the electrode constantly burns out, and its position relative to the metal surface must be corrected.

• Now you need to clearly understand the structure of the melted metal in the arc area. At the beginning of heating, a red liquid spot appears - this is not metal yet, but a melted coating of the electrode, which created a protective layer. After 2-3 seconds, a bright orange or even whitish drop will appear in the center of this spot with a slight tremor or ripples on its surface - this is the weld pool, the area of ​​molten metal. It is important to learn to clearly distinguish between liquid slag and the bath itself - the quality of the superimposed seam will also depend on this.
• As soon as the bath has formed, we begin to try to carry out its movement, smoothly moving the electrode, without changing the gap. A drop of metal always moves to an area of ​​elevated temperature, so the bath will also tend to follow the arc. For its part, the arc pressure somewhat pushes the bath in the opposite direction. Having worked practically and understood this principle, you can try to form a bead of weld metal on the surface of the sheet.
• For some complication of the task, it is best to outline a line on the metal surface, which should be maintained when creating a welded bead. The electrode will move along the line with small oscillatory movements to the sides - as shown in the diagram.

After applying this “seam”, it is necessary to let it cool, and then chop off a layer of slag in order to visually assess the quality. You may need to adjust the current strength. This, for example, will be noticeable in uncooked areas - the current is clearly insufficient. A higher value may cause the sheet to burn through. All this is determined only experimentally, it is difficult to give any clear recommendations.

The first exercise - creating smooth rollers

The porosity of the seams, the inclusion of slag particles in the metal structure is not allowed - this connection is not durable.

In the course of practice, it will be possible to decide which direction of welding will be most convenient - towards you or away from you, pulling the bath behind the electrode or vice versa, pushing it forward. Many craftsmen advise nevertheless to carry out welding, if even and high-quality rollers begin to turn out, you can proceed to the next stage - welding two workpieces.

• Welds by spatial position are lower, on a vertical plane (horizontal or vertical) and ceiling. Of course, you need to start from the lower ones - the ability to perform the rest will not come immediately, as experience is gained.

• According to the location of the mating parts, the seams are divided into butt, corner, tee and lap. Each of them has its own characteristics of application, electrode movement, cutting and setting of workpieces.
• Welding of two parts begins with tacks, which will ensure the stable position of the parts when applying the main seam. Usually, for tacking, the current is inserted by 20-30% more, while working on a short arc. In this case, the tacks should not be closer than 10 mm from the edge of the workpieces or near the holes. After applying the tacks, it is possible to check the correct position of the parts and make the necessary adjustments.

• First, you should learn how to apply single-layer seams on thin, 3-4 mm blanks. More complex variations, with root welding and filling, can be mastered, years with the simplest techniques, stable skills will be achieved.

You should not be afraid of such first failures - experience will definitely come

In a word, everything else will depend only on the diligence and regular practical training of a novice welder. It is good if there is an opportunity to contact a specialist so that he can evaluate the results. If not, you can compare the results of your work with the videos shown on the Internet with master classes in arc welding. Experience, hardness of the hand, the ability to choose the right parameters and self-confidence will definitely come.

Video: manual arc welding master class

Thanks to the reliability and durability of welding joints, there is not a single industry left that does not use this technology. In the household, it is also sometimes impossible to do without welding. Possession of skills in working with an electric welding machine will allow you to create any metal structures, from a simple fence in a summer cottage to openwork garden swing or multifunctional grill. We will tell you how to properly weld by welding, and reveal all the tricks and secrets of this craft so that your first seam is not only strong, but also neat.

Learning to cook with electric welding. Video tutorial

In order to learn how to cook with electric welding, it is not enough to study theoretical basis and learn the secrets of craftsmanship. Only the experience that is gained with every centimeter of the weld can bring you closer to the ability to weld metals.

A video on how to cook by electric welding will help you understand all the nuances of this craft, tell you about what other materials and tools, in addition to the welding machine, will be needed during the work.

Made in the form step by step lessons video of the welding process begins with a story about the preparation of surfaces before welding. Next, you will learn how to perform the simplest seams, and only after that you can begin to connect the parts.

Thanks to the recommendations in the video, welding your first structure will not be a big deal, and quality control of the seams will show how well you have mastered the welding technique. Watch a video on how to cook with electric welding, prepare theoretically, and then pick up an electrode and start creating.

Welding process technology

In order to learn how to cook by welding, you need to know that electric arc welding is a process of joining metals using an electric arc between the surface of the workpiece to be welded and the electrode . The resulting high temperature contributes to the simultaneous melting of the electrode and the metal base. This creates the so-called weld pool, in which the base metal is mixed with the molten electrode.

Bath size directly depends on welding welding mode, edge shapes surfaces to be joined, electrode movement speed, the position of parts in space etc. and ranges from 7 to 15 mm wide, 10-30 mm long and up to 6 mm deep.

The metal does not burn from high temperature gas layer, formed during the melting of the electrode coating, which displaces all oxygen from the melting zone. After the electric arc is removed, the metal crystallizes and forms common seam for welded surfaces, covered with a protective layer of slag, which is removed after cooling.

The advantages of electric arc welding are :

• high performance;
• possibility of welding various materials without the need to reconfigure the equipment;
• good quality weld;
• inexpensive consumables;
• availability.

AT limitations this method welding, you can record the mandatory presence of power supply and the need for preliminary preparation of the edges to be welded.

Getting ready to weld. Choice of materials and equipment

Before you start welding by welding, you need to understand for yourself that this process is accompanied by the formation of sparks and splashes of molten metal, the release of toxic gases and a danger to the eyes.

Therefore, in order to safely weld metal, it is necessary to stock up not only with good equipment, but also with the appropriate equipment.To start cooking with electric welding, you will need:

• welding machine;
• a set of rod coated electrodes;
• welder's hammer;
• metal brush;
• welding mask;
• overalls, suede gloves.

It is possible to cook by arc welding without a factory set of overalls. It is important that the protective suit is made of dense fabric with long sleeves, and it is better to tuck trousers into boots.

Choosing a welding machine

A good welding machine with the ability to adjust the current strength from 10 to 200A will help you learn how to cook by welding correctly. Of course, you can assemble a simple welding transformer with your own hands, but then about how to cook thin metal, you don’t even have to think about it, because for such work you need minimum power values. Factory-made devices are divided into:

• Welding transformers . Designed to lower the mains voltage while increasing the current. Being inexpensive and productive devices, they can weld metal quite well, but they have disadvantages in the form of an unstable arc, a strong "drawdown" of the supply voltage and a large mass.

• Welding rectifiers . Such devices are the same welding transformers equipped with a diode rectifier, thanks to which the alternating mains voltage is converted into a direct voltage necessary for the appearance of an electric arc. Welding metal with rectifiers is a little easier due to the higher arc stability. Otherwise, this type of welding machine has the same disadvantages as transformers.

• Welding inverters . Real electronic welding is possible thanks to the modern technological stuffing of such devices. They provide a lot of opportunities in order to cook with electrodes with the most optimal parameters. The electronic components of the circuit of modern inverters allow you to adjust not only the current strength, but also the ignition speed, arc forcing, etc., which ensures excellent weldability of parts. In addition, the inverters are compact and light in weight.

About what kind of welding is best to cook, disputes among welders go on unabated. Someone likes the simplicity and reliability of the transformer, someone is satisfied with manual welding with a rectifier. However, learning how to cook by welding is best done with a welding inverter. The ability to fine-tune the parameters will allow you to weld metal correctly from the very first steps.

Selection of electrodes for welding

For manual arc welding rod electrodes with protective coating . The metal of the rod must match the type of metals being welded, so different electrodes are used to weld steel, bronze or magnesium alloys.

The coating of the rod during the welding process melts and turns into slag, which, floating on the surface of the weld pool, protects the melt from the influence of oxygen and nitrogen in the air. Some coatings contain gas-forming additives, which, during the welding process, release a gas that limits the access of air to the melting zone.

Most often, the question of which electrodes to weld with is not worth it for beginner welders, since they usually begin to learn the craft by welding simple low-carbon structural steels.

The use of welding rectifiers makes it possible to use for such, as well as stainless alloys, UONII brand electrodes designed for direct current operation.

Electrodes of another brand - ANO , can be used for welding with both rectifiers and transformers, they allow welding with both direct and reverse current, so amateurs use them much more often than UONII.

Meanwhile, professionals in the question of which electrodes are better give preference to UONII. They cite as an argument the fact that this type of rod leaves much less slag behind, therefore cleaning the seam is required much less often, which significantly increases the speed of work.

Depending on the thickness of the parts to be welded, electrodes with a diameter of 1.6 to 5 mm are used. In addition, 4-5mm rods are used for cutting metals, setting the maximum current.

You can determine the required electrode diameter from the tables of the dependence of this parameter on the thickness of the parts, as well as using mathematical formulas. Novice welders rarely use rods with a thickness over 4mm.

Type of welding work(horizontal, overhanging, butt welding, etc.) practically does not depend on the diameter of the electrodes, which cannot be said about weld pool depth and seam width.

Since the specific welding current depends on the electrode cross section, the current concentration is higher at the end of a thin rod, so the penetration depth will be greater than when using a thick electrode. In turn, the use of rods with a diameter of 4-5 mm melts the metal less, forming a wider seam.

As you can see, it is impossible to answer exactly which electrodes to weld, since the right choice must take into account a lot of factors, ranging from the type of welding machine to the required width of the weld. In addition, it should be borne in mind that the quality of even the same brand of electrodes can vary significantly among products from different factories, so before you start welding, ask experts for advice.

We select the current strength and its polarity for welding with an electrode

After watching a video on how to cook by welding, you probably noticed the need current adjustment depending on the thickness of the parts and the diameter of the electrode. As a rule, it is not difficult for experienced welders to set the required value. For beginners, it is better to turn to special tables. Often the required parameters are indicated by electrode manufacturers on their packaging.

In order to weld metal correctly, the required current strength is determined by calculation or from tables, and then this parameter is set on the inverter control panel. The higher the current, the higher the arc power and the deeper the weld pool. . However, do not exceed the optimal value - the metal will begin to burn out and the seam will be of poor quality.

When setting the current value in order to cook by electric welding, be sure to take into account the location of the place of work. Maximum current is set for horizontal surfaces. When welding vertical seams it decrease by 15%, a ceiling demand current reduction by 20% and more.

If you cook with inverter welding or a rectifier, then the quality of work is affected not only by the current strength, but also by its polarity , that is, the direction of electron flow.

From the course of physics, everyone knows that electrons move from a region of negative charge to a region of positive. In order to properly weld the electrode, the polarity is changed by setting both the direct current (the electrode is connected to the minus of the inverter, and the part to the plus) and the reverse. Most often, a direct connection is used, since the part warms up more in this case, however, for welding thin products, the polarity is changed by switching the inverter terminals. Reverse polarity is also used for welding alloyed alloys that are prone to burnout of low-melting master alloys.

The good news for those who want to know how to weld with electrode welding is that reverse connection makes it easier to strike the arc . In addition, it is characterized by higher stability, which is an invaluable advantage when welding thin parts with an electrode, for example, sheet steel.

Safety precautions when carrying out welding work

Every novice welder wants to be reminded of the safety rules. Remember that welding is one of the most dangerous methods of mounting metal structures, so do not neglect the following rules:

• It is forbidden to carry out welding work in high humidity, as well as in frost.
• The use of a welder's mask and protective shield is mandatory. This will avoid burns to the cornea of ​​​​the eyes.
• Clothing should prevent metal splashes from entering the open areas skin. It is better to wear suede gloves on your hands, and best material for a suit of the welder is a dense tarpaulin.
• Welding work is associated with high temperatures and the risk of fire, so a container with water and a fire extinguisher must be present at the welder's workplace.

Also, be aware of the risk of electric shock, so avoid getting moisture on the welding machine, make sure that the cables do not touch hot surfaces.

Manual arc welding technique. How to cook by welding

Before proceeding to practical exercises, I would like to remind you once again about safety precautions. None wooden workbenches and combustible materials near the place of work. Be sure to put a container of water in the workplace. Be aware of the risk of fire.

In order to figure out how to cook by welding, we present to your attention detailed instructions and video of the welding process.

First try to strike the arc and hold it for the required time. To do this, follow our advice:

1. Using a metal brush, it is required to clean the surfaces of the parts to be welded from dirt and rust. If necessary, their edges are adjusted to each other.
2. It is best to learn how to cook by electric welding correctly with direct current, so connect the “positive” terminal to the part, install the electrode in the clamp, and set the required current strength on the welding machine.
3. Tilt the electrode with respect to the workpiece at an angle of about 60° and slowly pass it over the metal surface. If sparks appear, lift the end of the rod 5 mm to ignite the electric arc. Perhaps you failed to get sparks due to a layer of coating or slag on the edge of the electrode. In this case, tap the part with the tip of the electrode, as suggested in the video on how to properly weld with electric welding. The emerging arc is maintained with a 5 mm welding gap throughout the entire welding process.
4. If the arc lights up very reluctantly, and the electrode sticks to the metal surface all the time, increase the current by 10-20 A. If the electrode sticks, shake the holder from side to side, possibly even with force.
5. Remember that the rod will burn out all the time, so only maintaining a gap of 3-5 mm will allow you to keep a stable arc.

Learning to light the arc , try to slowly move the electrode towards you, while making movements with an amplitude of 3-5 mm from side to side.Try to direct the melt from the periphery towards the center of the weld pool. Having welded a seam about 5 cm long, remove the electrode and let the parts cool, then tap with a hammer at the junction in order to knock down the slag. The correct seam has a monolithic wavy structure without craters and inhomogeneities.

The purity of the seam directly depends on the size of the arc and the correct movement of the electrode during welding. Watch a video on how to cook by welding, filmed using protective filters. In such videos, you can clearly see how to maintain the arc and move the electrode to obtain a high-quality seam. We can make the following recommendations:

• Translational motion of the rod along the axis maintain the required length of the arc. During melting, the length of the electrode decreases, so it is necessary to constantly bring the holder with the rod closer to the part, observing the required clearance. This is what is emphasized in numerous videos on how to learn how to cook.
• Longitudinal movement of the electrode create a deposition of the so-called thread roller, the width of which is usually 2-3 mm greater than the diameter of the rod, and the thickness depends on the speed of movement and current strength. The thread roller is a real narrow weld.
• To increase the width of the seam the electrode is moved across its line, carrying out oscillatory reciprocating movements. The width of the weld will depend on the magnitude of their amplitude, so the magnitude of the amplitude is determined based on specific conditions.

The welding process uses a combination of these three movements to form a complex path.

After reviewing the video on how to weld with electric welding and having studied the diagrams of such trajectories, you can figure out which of them can be used for overlap or butt welding, with vertical or ceiling arrangement of parts, etc.

During operation, the electrode will melt completely sooner or later. In this case, welding is stopped and the rod in the holder is replaced. To continue working knock down slag and at a distance of 12mm from the crater formed at the end of the seam, set fire to the arc. Then the end of the old seam is fused with a new electrode and work continues.

Features of electric welding of metal pipes

learn to weld profile pipes best on thick-walled products using a welding rectifier or inverter. Depending on the diameter of the pipes, wall thicknesses can reach over 16mm, but you will most likely need to weld structural steel products with wall thicknesses up to 12mm. To weld a pipe, one-layer welding is often used, but to increase the strength of the joint, it is better to perform two or more passes.

When welding pipes, the seams are performed two half rings top down or bottom up.

If the direction of movement of the electrode corresponds to the first option, then 4-mm rods with low slag formation and organic coating are used. Such a coating burns out more slowly, forming a visor at the end of the electrode, on which they rely, performing transverse oscillations of small amplitude.

When welding from the bottom up, the amplitude is increased to 3-5 mm, and the speed of the rod is reduced.

Pipe connections perform:

• Butt (exact orientation of the ends of one pipe relative to another);
• Overlapping (overlapping pipes or parts on top of each other);
• Angle;
• Tee joint (one pipe is perpendicular to the other).

In order to weld one pipe to another, first clean up and prepare their ends and stack products in the workplace. Next, the elements are centered relative to each other and tacked in several places with spot seams. After checking the alignment of the pipe, it can be welded using one of the indicated methods.

If it is impossible to turn the pipes, they joints are made in layers. The first, root layer, serves for the initial connection of parts. The next, filling layers are designed to create a really strong, monolithic seam. And, if necessary, they perform a finishing, facing seam, which covers all defects and irregularities. A video on how to weld a pipe will help you better understand the features of such work.

After cleaning the seams from slag, the surface is carefully inspected for lack of penetration, pores, cracks and burns. If necessary, defects are eliminated by welding. If the seam meets all the requirements, then it is cleaned with an angle grinder.

Protection of metal from corrosion after welding

Remember, at the very beginning of the article it was said that in order to properly cook by electric welding, it is not enough to watch the video, but you also need to prepare theoretically? Agree that the text allows you to better understand the theory. Also, the videos somehow miss the need to protect details later on. We will try to eliminate this shortcoming.

Everyone knows that metal under the influence of atmospheric oxygen quickly begins to rust. Believe me, welds corrode even faster.

In order to protect metal surfaces from corrosion, painting is most often used. In order not to repeat this work every year, do it according to all the rules.

Primarily, must be removed old paint and rust . To do this, it is best to use metal brush attachments for a drill or grinder, but you can also work with a regular metal brush. Remember to protect your eyes with goggles or a shield.

After cleaning the surface treat it with a rust converter, and then coat it with a primer . Choose a primer composition specifically designed for metal work. After this layer has dried, you can start painting. A good result is given by acrylic and pentaphthalic enamels intended for outdoor use.

It is best to use not a brush or roller, but a spray gun for staining purposes. With it, you can apply a uniform, thin layer of paint that will not crack or peel off over time.

Modern welding work involves the use of various methods, this is not only traditional welding with a gas torch, but also with ultrasound and electron beams. But for domestic conditions and simple work, the method of electric arc welding using an inverter is preferable. This method is simple, although it requires compliance with certain rules and technology for forming a seam. To learn this method yourself, you can use the basics of inverter welding for beginners.

Electric welding is the most commonly used method, providing a strong, durable connection of parts. The method works on the principle of plastic deformation, in which the elementary particles of the electrode penetrate into the structure of the base materials of the parts to be joined. The result is the emergence of new molecular bonds with the highest strength.

For welding with an inverter, the following methods are used:

1. Gas press with the participation of an acetylene-oxygen mixture. The method is different high rates performance, it can be used not only in everyday life, but also in the gas, oil industry, in the construction of main roads, in mechanical engineering, civil engineering.
2. Contact welding is carried out using a low voltage electric current, but with a high force. The method includes spot welding, butt welding or seam welding.
3. In some cases, the following types are used: thermite, friction, electroslag or roller.

How to choose the right equipment

Inverter welding for beginners begins with the right choice of equipment. Currently, the market offers a large selection of welding equipment for domestic work or professional. Too cheap devices are not recommended when buying, as they will be able to provide arc stability, which leads to poor welding of the seam and its poor quality. In addition, for such devices there is a frequent “sagging” of voltage, their weight is unnecessarily large.

Two types of equipment can be used for electric welding: rectifiers and inverters. Rectifiers convert alternating current into a constant, ensuring the stability of the arc and good quality of the seam. Inverters not only convert alternating current to direct current, but also provide exactly the voltage that is most suitable for welding. In addition, such devices are lightweight and compact, their performance is quite high.

Inverters are the most efficient for electric welding due to their high performance, economy and compactness.

Externally, the inverter looks like a box weighing 3-7 kg with a carrying handle and cooling grilles on the case. On the front panel there are indicators of protection operation, networks, current adjustment, cable connectors, on/off toggle switches. The standard kit includes 2 cables with an electrode holder and a clamp for connecting the device.

Welding electrodes

The basics of work for beginner welders include learning to select electrodes that supply current to the junction of parts. For beginners, meltable rods are recommended, which are solid and easy to use, allowing even an inexperienced craftsman to make an even seam. For more experienced welders, it is better to use wire electrodes made on the basis of consumable powder.

When choosing, great attention should be paid to the diameter of the electrode. Optimal size considered 3 mm, for thin sheets you can take thinner rods, for massive and complex structures- large diameter.

Also, when choosing, one should be guided by technical specifications inverter, the type of surfaces to be joined and the properties of the metal. For example, 3 mm rods are usually used, the welding current will be 110-120 A. With a large metal thickness, rods with a diameter of 4-5 mm are already required, the current will be 140-160 A.

Work safety equipment

Before you start welding, you need to take care of protection. Welder equipment includes:

• leggings (special canvas mittens);
• a robe to protect the body from metal splashes and sparks;
• mask (light filters for the mask are selected depending on the working conditions);
• respirator (required for work in a confined space);
• shoes with rubber soles.

Gaiters are usually used for welding at height, for ceiling work, in other cases, gloves made of very dense fabric can be taken. For safety reasons, there should be a container with sand or water near the place of work.

Instructions for a beginner

Electric and gas welding for beginners are the basics of work and use of equipment. Experienced craftsmen recommend attaching the cable with the electrode to the body, then press it with your elbow and gently (the cable should retain some freedom) wrap along the forearm to the hand. This will provide the most convenient conditions for welding, in which the hand will be free.

Attention: Do not work with with bare hands, the use of a robe with long arms is a must!

After preparation, the current is set on the inverter, according to the welding materials and the electrode, then you need to take a stable posture, slightly move your elbow away from the body, lower the mask and start working. For beginners, it is recommended to start welding with parts larger than 20 cm, this allows you to practice working with long workpieces and breathe properly. One of the most common mistakes made by beginners is welding short parts in one go. As a result, it becomes difficult to work on large areas, and this negatively affects the quality of the seam.

The blanks must be fixed on the desktop, then put the electrode at a right angle, take it towards the seam by about 30-45 degrees. The distance between the rod and the surface should be 2-3 mm, when welding with a back angle, the slope is performed towards the seam, with the forward angle method, the electrode tilts away from the seam.

Attention: When welding, the electrode melts and decreases in size, so you must constantly monitor the distance and keep the angle!

You can ignite the electrode using two methods:

• striking (the rod must be drawn over the surface);
• by tapping (the electrode should be lightly struck on the surface in a perpendicular position).

If the rod is new, then it ignites immediately; for those that have already been in use, it is necessary to knock longer, since a slag film remains on the working end. Modern inverters make it easier to start, for this you can use the Hot Start function. For beginners, the anti-sticking function is great, that is, afterburner, which turns on when the rod approaches the surface too quickly. Against sticking, you can use another convenient feature - the Anti Stick function quickly turns off the current when sticking, which prevents the device from overheating.

Immediately after the appearance of the arc, a gap of 3-5 mm should be created and held in one position. This will ensure excellent penetration and evenness of the seam throughout its entire length. It is better to start cooking on a thread seam, gradually moving on to more complex options with oscillatory movements. These are such methods as herringbone, spiral, zigzag and many others. At the end of the seam, it is necessary to make light oscillatory movements to the sides, the electrode is removed only towards the deposited metal, which will eliminate the crater.

Checking the quality of the seam

Checking the quality of the seam after finishing work is very simple, you need to hit it with a hammer next to the work surface. If everything is done correctly, the slag will fly off completely, leaving no traces - only a smooth, even seam with an optimal width will remain.

If the slag is caught on something, this indicates lack of penetration, that is, too low a welding temperature. An overheated seam will simply break on impact.

The order of welding in a protected gas environment differs from electric welding in that the increased temperature in the working area is achieved by gas supply. This method is optimal for joining parts made of copper, brass, lead, cast iron; after completion of work, the metal can be hardened or cut. But this method has a big minus - heating is carried out for a large area, that is, it is not suitable for precision work or small workpieces.

Conclusion

Welding requires utmost attention and strict adherence to work standards. It is not very difficult to master the basics of welding, but it is necessary to competently approach the choice of equipment and electrodes, the operating mode, and follow safety rules. After mastering the primary skills, you can move on to more complex work, but not before the hand acquires confidence and clarity of movement.

Video lessons on welding with an inverter for beginners.

Modern welding machines, inverters, are a small device that is easy to carry and facilitates welding (compared to previous transformers). Learning to cook with an inverter is much easier than with a transformer device. Therefore, welding is no longer the prerogative of professionals, it has become a popular activity, accessible to mastery and application on own site. Consider how to learn how to weld metal using an inverter.

The device and principle of operation of the inverter welding machine.

Welding inverter device: how does an arc occur?

The inverter is a small metal box (up to 0.5 meters), weighing up to 10 kg. The main task of the welding machine is to produce the current of the specified parameters. To do this, the inverter converts the current from the network (alternating 220 Volts) into welding. The welding current of most household appliances is constant.

Direct and reverse connection of current.

Each inverter has two terminals: cathode (denoted by "-") and anode (denoted by "+"). An electrode is inserted into one terminal, and the second is connected to the metal to be welded. After the supply of electric current, a common electrical circuit is formed. At small gap chain (with a distance of a few millimeters) at the point of rupture, instant air ionization occurs and a welding arc occurs.

The main heat generation occurs in the arc. Its combustion temperature is 5000-7000 ºC. This is above the melting point of all metals used. When the arc burns, the edges of the metals and the electrode are melted and mixed. Slag is a lighter material, it floats to the surface and protects the base metal from oxidation and nitrogen saturation. After solidification, a weld is formed.

Current polarity and welding parameters - what is it?

Welding current can move from the cathode to the anode and, conversely, from the anode to the cathode. This creates a different polarity of the current. When current flows from the cathode - direct polarity. With reverse movement (from the anode) - reverse. What is direct and reverse polarity?

The use of different polarity is due to the fact that a higher temperature will be at the terminal to which the electric current is supplied. If the current is straight polarity, a higher temperature is formed at the anode (that is, on the surface to be welded). This is the most common type of welding, most beginner welders work with it. If the current is reverse polarity, a higher temperature is formed at the cathode (an electrode is connected to it). This is required when working with thin sheet metal and those steel grades that cannot be overheated (for example, high-alloyed ones).

The electrode diameter is selected depending on the thickness of the parts to be welded. The size of the electrode and the strength of the electric current are proportional to each other: the thicker the electrode, the stronger the current. For approximate calculations, it is assumed that the current strength is equal to the diameter multiplied by 3.5. That is, for a 3 mm electrode, the current strength will be: 3 * 3.5 \u003d 105 A.

Since the current strength is also affected by the location of the seam (horizontal, vertical or ceiling), the material of the electrode, it is easier for a novice welder to use the table of correspondence of the current strength to the diameter of the electrode and the choice of diameter according to the thickness of the elements to be welded (Fig. 1 and 2, respectively). Next, you can cook the metal with an inverter.

Advantages of an inverter over a transformer

Figure 1. Correspondence table for metal thickness and electrode diameter.

When learning, it is easier to master the art of welding with an inverter. It is easier to weld metal with an inverter, because the device provides a constant welding current (regardless of voltage fluctuations in the network). As a result, the arc burns steadily, the metal splashes slightly. The welding current is continuously adjustable.

cook welding inverter convenient for beginners due to the presence of additional functions. For example, the inverter can be configured with a "Hot-Start", it increases the welding current at the start of work (which makes it easier to start the arc). Another feature, Arc-Force, comes into play when the welder brings the electrode too close to the metal. In this case, the inverter automatically increases the current, accelerates melting and prevents sticking.

In case of sticking, the Anti-Sticking function is activated. It reduces the current and makes it possible to tear the electrode away from the metal and continue welding. The inverter consumes a relatively small amount of electricity. For example, for welding with an electrode with a diameter of 3 mm, a current of 4 kW is required (which corresponds to the operation of two electric kettles). The electricity savings make up for the relatively expensive price of the inverter.

Welding Safety Precautions

Figure 2. Electrode diameter and current.

Before starting work, the space within a radius of several meters is freed from wooden and other flammable objects. This is important for a beginner welder. The welding electrode or its fragment has a high temperature, they are able to set fire to boards, boxes, and paper trash that are nearby. Be sure to wear clothing that covers the entire body (long trousers, a jacket with long sleeves). This is also important for a beginner, as the spraying process can cause droplets of metal to get on the exposed skin of the hands or feet. Be sure to put on a protective mask with dark glass (light filter). This glass is impenetrable to sunlight. The burning of the arc through the light filter will be visible.

Watching the arc without a protective glass is dangerous, you can burn your eyes. A weak degree of burn (one or two times looked at the arc) leads to the formation of bright spots in front of the eyes (“picked up bunnies”). With an average degree of burn, the eyes hurt and itch (there is a feeling of sand in the eyes). A severe degree of burn leads to partial or complete loss of vision.

How to ignite an arc?

Safety regulations for welding.

To weld metal surfaces, you need to learn how to strike an arc and maintain it. First you need to connect the inverter terminals. We will work with a current of direct polarity, so we insert an electrode into the cathode terminal (“-”). For ease of operation, we take an electrode with a diameter of 3 mm. Welding with a thicker electrode is more difficult, leads to fluctuations in the arc length and unstable combustion, and requires more professionalism. We set the current to 100 A (for an electrode of 3 mm and a horizontal arrangement of the surfaces to be welded). We pick up the handle of the terminal with the electrode, turn on the inverter (apply current) and put on a protective screen.

Welding without a protective shield is prohibited in order to avoid loss of vision.

Feeling some discomfort is not worth the health of the eye apparatus. Before ignition of the arc, the end of the electrode is tapped against the metal to remove the coating from its edge. This makes ignition easier. There are two types of ignition:

1. Strike. It is necessary to bring the electrode to the surface of the metal and strike it (the action is similar to lighting a match). This is how a new electrode is ignited.
2. Touch. The electrode is brought to the metal and lightly touches its surface, after which it is immediately withdrawn to a distance of several millimeters. This is how the electrode is ignited when welding is interrupted (sticking has occurred or the welder has removed the rod too far from the metal surface).

Welding process: how to maintain the arc?

It is important to keep a small (3-5 mm) distance between the metal and the electrode. This distance is called the arc length. When it is increased, the arc stops burning.

The length of the arc is approximately equal to the diameter of the electrode. That is, for stable combustion and an even weld with an electrode of 3 mm, it is necessary to keep a distance of 3-5 mm from the surfaces to be welded.

If the electrode is too close to the metal surface, a short circuit occurs: the electrode sticks to the metal. To tear off the electrode from the surface to be welded, it is necessary to tilt it to the other side or turn off the inverter. When the power supply is interrupted, the electrode comes off.

The angle of inclination of the electrode can be different. It is best for a beginner welder to stick to about 70º from the metal surface (that is, with a slight deviation from the vertical position).

Figure 3. The trajectory of the movement of the electrode in arc welding.

In order to cook efficiently, you need to learn to visually (through the light filter shield) evaluate the size of the weld pool. The width of the reddish puddle in the light filter should exceed the thickness (diameter) of the electrode by 2 times.

The size of the pool is affected by the speed of movement of the electrode. If it moves too slowly, there is too much molten metal and a wide weld pool that prevents the arc from interacting with the base being welded, causing lack of penetration. If the arc is moved too fast, there will be insufficient edge melting and, as a result, also lack of fusion.

First steps in welding

The first welding operations should be tried on any unnecessary metal surface. After ignition of the arc, it is necessary to lead the electrode over the metal, trying to get an even weld mark. When it became stable to ignite the arc, you can begin to weld the surfaces. They are placed end to end to each other, an arc is obtained and the electrode is drawn along the connection line. In this case, the movements should not be rectilinear (along the seam), but oscillatory (now to the right, then to the left). A typical pattern of electrode movement during welding is shown in fig. 3.

After cooling, the slag layer on the outside is knocked down with a hammer and the quality of the joint is assessed visually. A good weld should be of uniform thickness, with no visible voids or gaps.

After practicing for one to two hours, most novice welders are consistently able to start the arc and keep it burning. Can be done simple connections metal surfaces. When you learn how to work with a welding inverter, you will be able to independently perform a variety of work on personal plot.

Welding is the most reliable connection non-detachable parts. AT Everyday life it is widely used in the manufacture of fences using chain-link mesh, greenhouse frames, stoves for saunas and garages, or various containers needed for summer cottages. A person who knows the skills of welding is able to create real masterpieces of openwork fences, roof sheds and other things necessary in everyday life on his personal plot.

What justifies the reliability of welding: the basics of welding

In terms of the strength of creating permanent joints, welding occupies a leading position. This is ensured by heating alloys of various metals using an electric arc, which leads to plastic deformation of the materials used. In this case, the mutual penetration of the elementary particles of the electrode into the structure of the materials being joined occurs. As a result, molecular bonds with ultrahigh strength appear.

Thanks to modern innovative technologies, now it is possible to use laser and electron beams, ultrasound and flame for welding gas burner. But for welding in domestic conditions, electric arc welding remains the most optimal, a source of energy to create an electric arc of which welding machines are used. various types including inverters.

Welding methods

Exist the following ways welding:

• gas press, using an oxyacetyl flame. The advantages of this type of welding are high productivity. Therefore, it is widely used in the oil and gas industry, in particular in the construction of highways for transporting oil and gas, as well as in mechanical engineering.
• Contact, carried out by an electric current having a relatively low voltage at a sufficiently high strength current. This method includes the following varieties: butt welding, seam and spot welding.

In addition, in some cases, roller and electroslag welding, friction and thermite, as well as a number of other varieties are used.

Choosing the right equipment

If you decide to master the technique of welding, then you will need welding equipment. It can be rented or bought. Currently, outlets offer welding machines equipped with a device that allows you to increase or decrease the current strength. Those who like to do everything with their own hands can make a welding machine from improvised means. In any case, you will need one of the following electrical energy converters:

1. Transformer for converting the alternating current of a household electrical network into the current necessary for welding. When choosing a unit of this type, it must be borne in mind that cheap models will not be able to provide the necessary stability of the electric arc. They are characterized by "sagging" voltage. Plus, they're too heavy.
2. Rectifier. This is a device that converts alternating electric current supplied to consumer networks into direct current. Unlike transformers, these units provide sufficient stability of the electric arc, which, in turn, improves the quality of the weld.
3. inverter. It converts the alternating current of the household power supply into the required direct current, with the voltage necessary for high-quality welding. This apparatus is characterized by compactness and light weight, easy ignition, fast action and high performance.

** Recommendation. The most efficient of these devices is considered to be an inverter, which is characterized by efficiency and high performance.

How to choose the right electrodes for welding

The most common, arc welding, requires electrodes that are designed to supply current to the weld. In most cases, this is a wire consisting of a special melting powder. But for those who are faced with welding for the first time, it is better to use electrodes in the form of solid rods coated with a melting compound. They allow even a beginner to make an even seam. The optimal diameter of the electrode rod for this category of welders is 3 mm. Smaller diameter electrodes are used to connect thin sheets of metal, and to use

Larger diameter electrodes require higher power equipment.

Welding safety (welder equipment)

Welding work is accompanied by bright light radiation and a lot of splashes of hot metal. Therefore, the welder must take care to protect the skin of his face and eyes from burns. For these purposes, you will need a special shield and mask. But not only the face and eyes need protection. The skin of the hands is more susceptible to burns from flying splashes of melting metal. Therefore, tarpaulin or suede gloves are a necessary means of ensuring safety. Perfect option- the presence of a dressing gown or overalls made of dense tarpaulin or rubberized fabric.

In order to ensure fire safety, in places where welding work is carried out, there must be a container with water or other means that protect against fire when an accidental spark enters.

Step-by-step instructions for performing welding work

1. The surface to be welded must be carefully protected. It should be free of dirt and rust.
2. Before starting welding work, it is necessary to insert the electrode into the holder of the welding machine and create an electric arc. To do this, it is necessary to cause the movement of current in the welding zone. This process can be carried out by striking the electrode rod on the metal or by touching the surface of the workpiece in the form of tapping.
3. As soon as an electric arc appears, it is necessary to create a gap between it and the surface to be joined. This gap should have a constant value and be in the range from 3 to 5 mm.

** Recommendation. To obtain a smooth seam, without defects, it is necessary that the gap remains constant throughout the entire time of welding. Otherwise, the arc will be interrupted and the quality of the weld will deteriorate.

1. The angle of inclination of the rod should be 70?. But it can be changed, in order to ensure the comfort of welding.
2. Equally important is the stability of the supply of electric current. It must be borne in mind that too much of its force will cause the metal to melt, and at a low one, the arc is extinguished.

After you have mastered the technique of making a weld in the form of a roller, you can proceed directly to making permanent joints. Work begins with the creation of an arc. Then the welder proceeds to the direct connection of the parts. At the same time, his hand must make oscillatory movements from one element to another. The weld (trajectory of movement) can be made in the form of a herringbone, loop, zigzag, etc. At the end of the work, it is necessary to clean the seam from the formed slags.

Once you have mastered the basic skills of welding, you can move on to more complex operations, making butt and tee joints, as well as overlap and corner, moving in different directions. As soon as the hand gains confidence, you can start making more complex products.

Video - manual arc welding for beginners