The main mistakes of a novice welder and how to deal with them

In a private house, country house or garage, quite often there is a need to connect various metal parts and create structures from them. It makes no sense to turn to professionals for help every time in such a situation, because you can purchase an automatic welding machine yourself.

A wide selection of different devices are available in stores in different price categories, so welding with an inverter for beginners is the best that the market has to offer.

Basics of electric welding

Inverter devices are characterized by fairly high efficiency and ease of operation. The main load for the operation of such equipment falls on the electrical network.

It has storage capacitors that allow you to accumulate electricity and ensure an uninterrupted welding process and soft ignition of the arc.

Unlike old devices, which provide a maximum boost of electricity for work, which can result in traffic jams, an inverter allows you to safely operate from a household power supply.

Defects in welds.

To understand how to cook using inverter welding, you need to understand the basics of its operation.

In such manual welding machines, the arc is formed as a result of contact of the electrode with the product. Under the influence of temperature, the metal and electrode melt. The molten part of the rod and the product form a bath.

The coating of the rod also partially melts, turning into a gaseous state and closing the weld pool from oxygen. This allows you to protect the product from oxidation.

Each electrode, depending on its diameter, is designed for a certain current strength. If you reduce it below the required value, then the seam will not work. Increasing this parameter will allow you to form a seam, but the rod will burn out too quickly.

At the end of the welding work, the coating cools down, turning into slag. It covers the connection of metal parts from the outside. By tapping the seam with a hammer, it is quite easy to get rid of the slag.

There are also simple welding rules. To ensure that the arc does not go out during work, the welder should maintain a constant distance between the rod and the workpiece.

This is not easy to do because the electrode melts, so it must be fed into the welding zone at a constant speed. In addition, you must try to guide the electrode evenly along the joint in order to obtain a seam of maximum quality.

You can learn more about how to assemble a subwoofer with your own hands and about electronic radio circuits on the website - www.radiochipi.ru.

Technique

If you follow the rules of welding, you can smooth out errors arising from deviations in the angle of inclination of the holder. Depending on the required filling of the weld, several methods are adopted:

• triangle. This wiring allows you to reliably weld the root of the seam. It is used for welding parts with a thickness of over 6 mm and provides reliable heating of the middle part of the seam. The method is most common when welding pipes with a fixed joint;
• guiding the electrode along a broken zigzag line. It is used when welding structures with a metal thickness of less than 6 mm. The highest quality seams are obtained when butt welding and in the lower position. Such wiring can be used to weld joints efficiently without ensuring bevel of the edges;
• circular or elliptical movements with the electrode. This method ensures reliable heating of both planes of the parts being welded. It is used when welding structures made of alloy steels and in a vertical position of the joint.

In this case, it is important to ensure simultaneous advancement of the core together with the movements responsible for heating the joint and filling the seam. There are three promotion options that can replace each other.

The first option is translational movement along the axis of the core. This movement is necessary to maintain an arc with a constant length and ensure a certain speed of welding structures.

The second type is movement along the axis of the seam in a straight line. In this case, the welder has the opportunity to control the time of metal melting and provide a certain leg.

The third option is to make oscillatory movements at an angle of 45° across the seam. This method is used to ensure heating of the edge of the part.

The welder can adjust the width of the bead on thin metal. This option for advancing electrodes is indispensable for multilayer joints . Used for root seam.

Welding methods

Nowadays there are many methods used for welding. They are divided according to various criteria. This information will be useful for a beginner, so you should definitely read it.

Depending on the heating, the edges of the product may completely melt or be in a plastic state. The first method also requires applying certain forces to the parts being joined - pressure welding.

In the second, the connection is formed as a result of the formation of a weld pool in which there is molten metal and an electrode.

There are other welding methods in which the product does not heat up at all - cold welding, or is not brought to a plastic state - connection using ultrasound.

Methods and types of welding.

Other types of welding are listed below:

1. Forge. In this method, the ends of the joined products are heated in a forge and then forged. This method is one of the most ancient and is currently practically not used.
2. Gas press. The edges of the products are heated with oxygen acetylene over the entire plane and brought to a plastic state, after which they are subjected to compression. This method is highly efficient and productive. Used in the construction of gas pipelines, railways, and mechanical engineering.
3. Contact. The parts are included in the electrical circuit of the welding equipment and current is passed through them. A short circuit occurs at the point of contact of the parts, as a result of which a large amount of heat is released at the junction. It is enough to melt and join metal.
4. Butt, point and suture are varieties of the contact method of fastening the product.
5. Roller. Used in joining sheet structures that require high-quality and reliable seams.
6. Termite. The metal is held together by burning thermite, a mixture of iron oxide powder and pure aluminum.
7. Nuclear-water. The edges of the product are melted by the action of an arc burning between two tungsten electrodes. The electrodes are connected to special holders through which hydrogen is supplied. As a result, the arc and liquid metal of the weld pool are protected by hydrogen from the harmful effects of atmospheric gases such as oxygen and nitrogen.
8. Gas. The essence of the method is to use a flame to heat and melt parts. A flame is produced by burning a flammable gas in an oxygen atmosphere. The gas-oxygen mixture is produced using special burners.

Under the action of an atomic-hydrogen welding arc, hydrogen molecules are split into atoms and then recombined upon contact with cold metal. As a result of this process, a large amount of heat is released. The method is used for welding metals of small thickness, copper and alloys based on it.

The gas welding method refers to fusion welding. The gaps between the products are filled using filler wire. This method is widely used in various areas of human life. Most often found when joining thin-walled products, non-ferrous metals, cast iron.

When working with an inverter device, the polarity of the electrodes is of no small importance. Depending on the scheme, the heating intensity of the part changes, which allows you to create different welding conditions.

Other types of welding

The most important element of any metal structure is the weld. In this regard, the technique of welding vertical seams, as well as other connection options, will be extremely useful for beginners.

There are a large number of methods used to form reliable joints in the case of different locations of parts relative to each other. Special techniques for moving electrodes have also been developed, for example, herringbone, boat, etc.

The simplest types of welding include working in a horizontal position. However, there are more complex types of seams.

Butt

The easiest way to carry out this type of connection is not on a vertical plane, but on a horizontal one.

Drawing of welding seams.

The welding process can be performed in several ways:

• in space;
• on a removable copper lining;
• with a preliminary seam.

In the first case, the most difficult thing is to boil the root throughout the entire product. The use of a copper lining can simplify the task. Due to its high thermal conductivity, it will prevent melting of the surface under the parts as a result of contact with molten material. It can be easily removed after finishing work.

Welded multilayer

This technology involves several passes. Before each pass, the previous layer is cleaned and cooled. In this regard, this connection method differs significantly from others.

The layers are welded using electrodes of different diameters. We weld the bottom one with rods 3-4 millimeters in diameter, and the subsequent ones - 5-6 millimeters. The topmost layer is convex, in addition, it performs heat treatment of the lower layers.

https://www.youtube.com/watch?v=yEz_cweZtyQ

Ring

Used in joining pipes and various parts of shut-off valves. It is a mixed type of arc welding.

First, a vertical seam is made on the side of the pipe using electric welding, then a horizontal seam is formed around the circumference. In the same way, welding of plates located on the ceiling is carried out.

Features of the preparation technique for circumferential welding are as follows:

• the product is thoroughly cleaned;
• deformed areas are trimmed and leveled;
• the edges are cleaned to a shine.

Processing of joints during the welding process is carried out continuously, and turns are welded in several passes. Each subsequent connection is applied only after the previous one has been cleared of slag.

If cracks are found, they are removed and the resulting fragment is welded again.

Ceiling

Characteristics of different types of welded joints.
Every inexperienced welder will be confused when faced with the need to weld a ceiling seam using electric welding. This type of connection can easily be called the most complex welding seam. It should be noted that ceiling welding causes a lot of problems associated with the inconvenient position of the master when working.

Drops of hot metal tend to break off and fall down, which further complicates the work process. The molten metal itself is held in the bath due to the action of surface tension.

Welding a ceiling seam involves positioning the electrode normal to the surface of the product. In this case, the rod performs circular movements. This way it is possible to expand the connection.

The arc should be short to avoid undercuts. It is necessary to weld the ceiling seam according to the following method - the metal should harden at the highest speed. A similar effect can be achieved by using electrodes with a coating that has a high melting point.

In addition to circular movements, you should also make vertical movements. Moving the electrode away from the bath will extinguish the arc. As a result, the metal will begin to cool and the bath will shrink.

Thus, in addition to the standard defects formed during welding, welding of ceiling seams is characterized by another unpleasant feature, which is impossible to get rid of. When making such a connection, you must understand in advance that it will be weakened and less reliable than any other.

In connection with the above, such joints are almost completely absent in industrial production.

Step-by-step instructions for welding with an inverter

First of all, for welding you need to have protective elements:

• gloves made of rough fabric;
• welding mask with a special filter protecting the eyes;
• a rough jacket and trousers made of material that will not catch fire from sparks that appear during welding;
• closed shoes with thick soles.

Electrode position during welding.
Before you start welding with a welding inverter, you must take the necessary measures aimed at creating safe working conditions.

Proper preparation of the workplace consists of:

• ensuring the necessary free space on the table, you should remove all unnecessary objects that could get splashed;
• creating high-quality lighting;
• Welding work must be performed while standing on a wooden floor that protects against electric shock.

Then the current is adjusted depending on the thickness of the parts and the electrodes are selected. The latter need to be prepared. If they were just purchased in a retail chain and their quality is beyond doubt, then this step can be skipped.

If the rods have been in an unheated, damp room for a long time, then they need to be dried for two to three hours at a temperature of 2000 degrees. For these purposes, you can use an old oven or special equipment, if available.

After preparing the electrodes, the ground terminal is connected to the product.

To obtain a high-quality and reliable connection, the metal must be prepared:

• rust is completely removed from the edges of the product;
• using solvents, various contaminants are cleaned;
• At the last stage, the edges are checked for cleanliness; the presence of grease, paint and other contaminants is unacceptable.

Next you need to connect the welding inverter. It is better to carry out training on a thick metal sheet, forming a seam in the form of a roller. Make the first connection on metal lying horizontally on the table. Draw a straight line on it with chalk along which the seam will go.

Electrical circuit of the inverter.

In the process of training on such an object, you can significantly improve your welding technique.

The welding process begins with ignition of the arc.

There are two ways to perform this action:

• scratching on metal;
• tapping on metal.

The choice of method depends on the person’s preferences; the main thing when igniting is not to leave traces of welding outside the joint area.

After igniting the arc from contact with the metal, the arc is ignited, the welder removes the electrode from the surface of the part a short distance corresponding to the length of the arc and begins welding.

As a result, a weld is formed at the junction of two metal parts. It will be covered with scale - scale on the surface. It needs to be removed. This is very easy to do by tapping the seam with a small hammer.

From my personal experience

Why did I say that welding has changed a lot recently? This is because equipment and technologies have seriously developed and do not stand still. Today, instead of a huge transformer that will burn out all the wiring in the house, you can buy an inexpensive inverter that consumes no more electricity than a regular electric kettle.

So, with this same inverter you can do all the work around the house: weld a barbecue and a fence, weld a wheelbarrow or shovel. With the advent of an inverter in my house, I almost gave up the use of bolts, studs and a bunch of nuts, which were previously wasted in large quantities.

Perhaps many, like me, will benefit from my modest advice and developments that I have learned over many years. Please don't judge harshly.

Forward and reverse polarity

Melting of the metal for welding occurs under the influence of an arc. It, as noted above, is formed between the surface of the product and the electrode, since they are connected to opposite terminals of the device.

There are two main options for welding, differing from each other in the order of connection and called direct and reverse polarity.

In the first case, the rod is connected to the minus, and the part to the plus. In this case, an increased flow of heat occurs into the metal. As a result, a deep and narrow melting zone is formed.

Direct and reverse polarity.

With reverse polarity, the electrode is connected to the positive, and the product to the negative. In this case, the melting zone is wide and shallow.

The choice of polarity is entirely determined by the product you are working with. Welding can be performed with two types of polarity. When choosing, you should take into account the fact that the element connected to the positive is subject to greater heating.

For example, it is difficult to weld thin metal products due to possible overheating and burning. In this case, the part is connected to the minus. Currents are also selected according to the diameter of the electrode and the thickness of the metal. This data is taken from a special table.

Oscillatory movements across the seam (3)

Oscillatory movements across the weld axis (electrode manipulation) are performed to obtain a weld of the required width, normal penetration of the weld root and edges, and slow down the cooling of the weld pool. Manipulation of the electrode allows you to obtain a seam with a length of 2 to 4 electrode diameters.

All types of electrode manipulations differ in shape, size and position in space:

• for uniform heating of the weld pool;
• for enhanced heating of the weld root;
• for enhanced edge heating.

Rice. 2. Oscillatory movements of the electrode

Common oscillatory movements during manual arc welding (Fig. 2):

1. straight along a broken line with a step of 2-4 mm - convenient to use when there is no risk of burning through the metal, for welding sheets of metal in the lower position without bevelling the edges);
2. with a crescent pointing its ends towards the weld pool - for welding butt welds with beveled edges in the lower position and for fillet welds with a leg of no more than 6 mm;
3. a crescent with the ends directed in the direction of welding - for welding butt and corner welds with a leg up to 6 mm in any position;
4. triangle - for welding butt welds and corner welds with a leg of more than 6 mm;
5. triangle with heating of the weld root - for welding thick-walled structures;
6. loop-shaped - to avoid burns at the root of the weld and increased heating of the edges (especially for welding high-alloy steels).

Effect of electrode feed speed

The feed rate of the welding electrodes must provide the required amount of molten material supplied. Not having enough of it can lead to undercutting. This factor is very important in both direct and reverse polarity when welding.

During electric arc welding, due to the rapid movement of the rod along the joint, the arc power may not be enough to heat the metal. The result is a shallow seam that lies on top of the metal. The edges remain unmelted.

Slow advance of the electrode leads to overheating. In this case, it is possible to burn the surface and deform the thin metal.

Modern welding machines have a wide range of different functions and capabilities. Nevertheless, at the moment, most of the quality work done is still determined by human skill.

How to hold a welding arc

Whatever method of igniting the electrode is chosen, it is important to maintain a short distance at the moment the electrode is separated from the metal. Only in this case the welding arc will not go out, it will burn stably, melting the base metal well.

Every novice welder should first of all practice igniting the electrode and holding a short arc. The shorter the welding arc, the better for welding. Ideally, the arc length when welding with a covered electrode should be 2-3 mm, and no more.

To break the welding arc, quickly move the electrode upward without holding its end above the metal surface for a long time. If you neglect this advice, then a long arc will arise, which will bring with it a number of defects when welding metals.

Effect of current

Welding current selection table.
When mastering the basics of welding with an inverter, it is important to understand what current strength needs to be set in each individual situation. A properly configured inverter welding machine is the key to success.

Data on the current value are taken from the table, which also shows the size of the electrodes. However, these current values ​​are not exact; they are plus or minus several tens of amperes.

Precautions before cooking with electrodes

Following safety rules can prevent serious injuries and threats to the lives of workers:

1. Operate only with serviceable equipment. Before welding, inspect the machine, cables and holder. Make sure there are no mechanical damages or violations of insulation integrity.
2. Observe the temperature regime: temperature above +5°C, humidity not higher than 80%. To do this, you need to install heating in the work area.
3. Use personal protective equipment.
4. Keep your work area clean and free of clutter.
5. All flammable materials must be located no closer than 5 meters from the workplace.
6. When cleaning with an angle grinder, protect the work area with fireproof screens.
7. Prepare a working carbon dioxide fire extinguisher of sufficient capacity.

Features of welding thin metal

In everyday tasks, we are most often faced with the need to join thin metal. In this case, it is necessary to remember the basics of inverter welding for beginners, namely the importance of connecting the product to the correct pole. Thin parts are connected to the “minus” of the welding machine.

To learn how to weld correctly and get beautiful seams, you need to practice.

Here are some useful tips that can help improve your skills:

• start cooking using the minimum current;
• form the seam at an angle forward;
• use reverse polarity;
• secure the part to reduce distortion during welding.

How to avoid common mistakes when welding

Well, first of all, you shouldn’t even try to weld thin metal with 3-4 mm electrodes. It is important to choose the diameter of the electrode so that it does not burn through the metal. However, it’s not just the thickness of the electrode, since its type and brand are also important.

In addition, it is important to learn how to properly hold and guide the electrode during welding. Typical mistakes made by electric welders include narrowing and widening of the weld seam, and an uneven amount of deposited metal in height.

If you move the electrode too quickly, then less metal than necessary will enter the weld pool. In this case, we will get a very narrowed seam. Conversely, if you slow down the movement of the electrode, a strong widening of the weld seam will occur. Consequently, the more uniformly the electrode moves, the more beautiful and high-quality the weld will be.

Common mistakes made by newbies

Arc welding diagram.
Beginner welders tend to make mistakes due to ignorance of the basics regarding the use of welding equipment. For example, beginners may not know how to choose the correct polarity for welding with an inverter, which will lead to poor-quality joint formation or even burning of the part.

The following main errors can be identified:

• neglect of safety precautions;
• incorrect choice of welding machine;
• use of low-quality or unprepared electrodes;
• work without trial seams.

For beginners, it is worth separately noting one feature if you cook Resanta by welding. This equipment is very popular, but it has short connection cables, which can create inconvenience in operation.

How to guide an electrode for a novice welder

After practicing igniting the electrodes, you can begin welding metals. To do this, the electrode must be brought to the site of the future seam, so that it seals the gap. That is, the electrode melts and heats the edges of the metal. When the electrode melts, additional metal is formed, which melts the gap, mixing with the base metal.

Thus, a weld seam is formed.

At the initial stage of training, the main thing is to correctly guide the electrode along the connection. The movement of the electrode should resemble a “herringbone” shape. You kind of grab the edges of the metals of the electrodes, melt them, and then fill them with metal.

Here it is important to take into account not only the movement of the electrode, but also the speed, which largely depends on the thickness of the metal you are welding.

Let's sum it up

Having learned to work with welding equipment, it will be possible to solve many everyday problems that often arise when working in the country or in the garage. Beginners should pay special attention to the polarity of welding parts of different thicknesses with an inverter.

By understanding how to properly configure the equipment and choose an electrode, you will be able to obtain high-quality seams on any product. Be sure to pay attention to the forward and reverse polarity of connecting the welding inverter.

When welding thick parts, direct polarity is used when welding with an inverter, and for thin parts, reverse polarity is used.

Cleaning welds

After welding, splashes of scale, drops of metal and slag remain on the metal surface. The seam itself is usually convex, protruding above the surface. All these shortcomings can be eliminated: cleaned up.

Cleaning the seams after welding is done in stages. At the first stage, using a chisel and a hammer, knock off scale and slag from the surface. On the second, if necessary, the seam is compared. Here you will need a tool: a grinder equipped with a metal grinding disc. Depending on how smooth the surface should be, different abrasive grain sizes are used.

Sometimes, when welding ductile metals, tinning is required - covering the weld with a thin layer of molten tin.

How to learn to weld by welding - a guide for beginners

Welding is a high temperature process. To carry it out, an electric arc is formed and held from the electrode to the workpiece being welded. Under its influence, the base material and the metal rod of the electrode melt. As experts say, a weld pool is formed, in which the base and electrode metals are mixed. The size of the resulting pool directly depends on the selected welding mode, spatial position, speed of arc movement, shape and size of the edge, etc. On average, its width is 8-15 mm, length 10-30 mm and depth - about 6 mm.

The electrode coating, the so-called coating, when melted, forms a special gas zone in the arc area and above the bath. It displaces all air from the welding area and prevents the molten metal from reacting with oxygen. In addition, it contains pairs of both base and electrode metals. Slag forms on top of the weld, which also prevents the melt from interacting with air, which negatively affects the quality of welding. After the electric arc is gradually removed, the metal begins to crystallize and a seam is formed that unites the parts being welded. On top of it there is a protective layer of slag, which is subsequently removed.

During the welding process, the electrode coating melts, forming a special gas zone. Inside it, the base metal and electrode are mixed

It is best for novice welders to gain their first experience under the guidance of a specialist who can correct possible mistakes and give useful advice. You should begin work by securely fastening the part. For fire safety purposes, you need to place a bucket of water near you. For the same reason, you should not carry out welding work on a wooden base and be careless with even very small remnants of the used electrode.

Connecting the welding machine

For welding to work safely, you need to connect the machine to the network, observing the following rules:

• First you need to check the voltage and frequency of the current. This data must be the same on the network and on the device body.
• We set the calculated value of the current power on the welding machine, which should correspond to the selected electrode diameter. If the welder settings block allows you to select the voltage, you need to set it right away. The connection is made through a special plug and grounding lug.
• We securely fasten the “grounding” clamp. We check that the cable is insulated and neatly tucked into a special holder.
• Be sure to check all connections, cables, plugs.
• You can use a special extension cord that is connected without intermediate connections.
• In older houses with weak wiring, voltage drops may occur. It stops the work process and can damage the welding equipment. In this case, you need an electric generator that will provide voltage at the operating level.

The welding machine is simple

How to choose the right current

Welding current is an important indicator of welding and determines the type and nature of the seam and work productivity. The higher the current, the more stable the arc and the greater the penetration depth. The current strength depends on the location of the workpieces in space and on the size of the electrode. The highest value is set for welding horizontal workpieces. For vertical seams, the current value used is 15% less, and for ceiling seams - 20%.

The current strength depends on the location of the workpieces and the size of the electrode

How to strike an arc

The first way is touch. To do this, we install the electrode at an angle of about 60° relative to the product. Slowly move it across the surface. Sparks should appear, now we touch the electrode to the metal and lift it to a height of no more than 5 mm.

If the operation was performed correctly, the arc will light. The five-millimeter gap must be maintained throughout the welding. It should be taken into account that when properly welding metal using electric welding, the electrode will gradually burn out, so we constantly bring it slightly closer to the metal. The electrode should be moved slowly; if it suddenly gets stuck, you will have to slightly swing it to the side. If the arc does not ignite, the current may need to be increased.

The second method is chirping. You need to bring the electrode to the surface of the workpiece and strike it over the part, as if you were lighting a match. You can make it easier to ignite the electrode by tapping the coating on its edge.

Tilt and movement of the electrode

Once you can light and maintain the arc without any problems, it’s time to move on to fusing the bead. We light the arc, slowly and smoothly move the electrode horizontally, performing slight oscillatory movements with it. In this case, the molten metal seems to be “raked” to the very center of the arc. The result should be a strong weld with small waves formed by the deposited metal.

For a novice welder, it is better to keep the electrode angle at about 70 degrees, that is, with a slight deviation from the vertical. Below is a diagram of arc welding.

Electrode tilt angle is about 70 degrees

If during the process of welding parts the electrode has burned out almost completely, and the seam has not yet been completed, we temporarily stop the work. We replace the used element with a new one, remove the slag and continue working. At a distance of about 12 mm from the depression formed at the end of the seam, which is also called a crater, we light the arc. We bring the electrode to the recess so that an alloy is formed from the metal of the old and newly installed electrode, after which welding of the seam continues.

During the welding process, the electrode makes certain movements, mainly translational, longitudinal and transverse. Their combinations make up various types of seams, the most common ones are shown in the diagram

The arc movement trajectory during the welding process of parts can be done in three directions:

• Progressive. Involves moving the arc along the axis of the electrode. This makes it fairly easy to maintain a stable arc length.
• Longitudinal. Forms a thread welding roller, the height of which depends on the speed at which the electrode moves and its thickness. This is a regular seam, but very thin. To secure it, in the process of moving the electrode along the welded seam, transverse movements are also performed.
• Transverse. Allows you to obtain the desired seam width. Performed by oscillating movements. Their width is selected based on the size and position of the seam, the shape of its cutting, etc.

In practice, all three basic movements are used, which are superimposed on one another and form a certain trajectory. There are classic options, but each master usually has his own handwriting. The main thing is that during the work the edges of the joined elements are well fused, and a seam of the given shape is obtained.

As a rule, all three directions are used; they can overlap each other and form a trajectory

Making welds

Ceiling welding seam

This seam is considered the most difficult, since the weld pool is turned upside down and is located above the welder. Select an electrode no larger than 4 mm and move it slightly to the side so that the metal does not spread. Use a short arc and completely dry electrodes; the seam for ceiling welding should be thin. The movement is self-directed, making it easier for the welder to control the quality of the seam. There are several ways to do it:

• ladder;
• crescent;
• back and forth.

The ceiling seam is considered the most difficult

Video: making a ceiling seam

Vertical

When making such a seam, you can move the electrode from top to bottom or from bottom to top. To prevent the metal from draining, the electrode should be placed at an angle of 45-50 degrees downward from the perpendicular position. Experienced welders recommend making this seam in one pass.

When making a vertical seam, the electrode is positioned at an angle of 45-50 degrees

Video: vertical seam

23.03

Making a horizontal seam

When making such a seam, the main difficulty lies in the metal flowing down. To solve this problem, the welder must adjust the electrode angle and pass speed. Welding is carried out from left to right or right to left.

When making a horizontal seam, you need to correctly select the angle of inclination of the electrode and the speed of passage

Angular

When forming fillet or tee welds, the parts are placed at different angles in a boat so that the molten metal flows into the corner. Then they are tacked by welding on both sides, one edge of the structure should be slightly higher than the other. The movement of the electrode begins from the bottom point.

In fillet welding, the movement of the electrode begins from the bottom point

Welding current symbols for electrodes, voltage and polarity

AC and DC current, any polarity

AC and DC current, reverse polarity (positive on electrode)

Alternating and direct current, straight polarity (minus on the electrode)

Direct current, reverse polarity (positive on electrode)

Direct current of any polarity

How welding current for electrodes affects welding

When carrying out the welding process, it is necessary to select the correct current value. It is this parameter that largely influences the quality of the weld.

Low welding current

can lead to unstable arc combustion, the appearance of unwelded areas, the welding process will be constantly interrupted and, as a result, the welder will receive a poor-quality connection.

A value that is too high will result in overheating or burnout in the welding zone, as well as intense spattering.

In general, the choice of voltage indicators is influenced by several factors :

• brand and diameter of welding materials;
• spatial position of the rod during welding;
• voltage polarity (see the peculiarities of constant and alternating welding);
• seam size ;
• method ;
• type and thickness of metals being welded.

Types of Welding Machines

To choose the right welding machine, it is necessary to take into account all the pros and cons of various types and models of welders.

Transformers are the simplest and most traditional devices, quite heavy in weight, made on the basis of a step-down transformer, which brings the voltage value to that required for operation. The peculiarity of transformers is that they operate on alternating current, which creates an unstable arc. In combination with an increased amount of slag and gas impurities, such an arc contributes to metal spattering and spoils the appearance of the weld. A high-quality weld with such a device can be made by an experienced welder with skills in working on a transformer.

A simple device operating on alternating current

Rectifiers are welders that can convert alternating current into direct current and reduce the network voltage using semiconductor diodes. Direct current produces a stable arc and allows you to make the welding seam uniform and sealed, strong and beautiful. The rectifier is universal, all types of electrodes are suitable for it, all types of metals can be welded with this device: stainless steel, aluminum, copper, titanium, various alloys.

Universal welding machine, suitable for all types of electrodes

Inverters are very popular because they are light weight, excellent functionality, and automated settings. Such technical characteristics allow beginners to work on it. The design of the device includes a number of blocks that convert alternating current from the network into high-power direct current. The advantage of this type of welder is:

• possibility of precise settings;
• performing a wide range of tasks;
• stable arc;
• resistance to power surges;
• high quality welding, smooth seam;
• work with all types of electrodes;
• connection of all types of metals of any thickness and position in space.
• has additional functions that prevent electrode sticking and tear-off drops;
• possibility of igniting the electrode at maximum current supply;

The disadvantages include:

• the need for frequent dust removal;
• limited cable length of 2.5 m;
• impossibility of working at air temperatures below – 15 degrees.

The inverter is suitable for novice welders

Semi-automatic machines come in two types. The former increase the productivity of welding work due to continuous wire supply. In this case, there is no need to constantly change the electrodes. The seam is smooth, continuous and without defects. The latter operate in a gaseous environment; for this they use oxygen, nitrogen and carbon dioxide, as well as argon and helium. Gas welding has the following advantages:

• one apparatus is designed to work with both gas and wire;
• excellent quality and aesthetics of the seam;
• stable, even arc;
• high functionality;
• Possibility of welding complex joints.

With this machine you can make a high-quality weld