How to burn a hole with an electrode

Welding burns through metal: what to do, how to weld with an inverter?

• Why does welding burn through metal?
  • Selecting the mode and electrodes for welding

Welding burns through metal: what to do, how to weld with an inverter?

To prevent welding from burning through metal, you need to have at least a little experience as a welder and knowledge of what current to set on the inverter and what electrodes are best for welding thin metal. It is with welding of thin metal that this problem most often arises, when the electrode is moved upward from the surface, a long arc appears, completely burning a hole in the metal.

It is for this reason that when welding thin-walled pipes it is necessary to keep the arc as short as possible so as not to burn through the metal. Also, the thickness of the metal should not be less than the diameter of the electrode, since it is much easier to burn through the metal with thick electrodes. What to do if welding burns through metal and how to avoid this will be discussed below.

Why does welding burn through metal?

There are several basic rules when setting up and adjusting the inverter, which will help you not burn through the metal when welding:

• Firstly, it is better to weld thin metal using a direct current inverter, connecting the electrode holder to the positive terminal of the device, and the mass to the workpiece being welded. Thus, the higher temperature will fall on the electrode, and not on the thin-walled metal.
• Secondly, in order not to burn the metal when welding with an inverter, you need to weld only at low currents, from 30 to 50 A.

• Thirdly, the thickness of the metal being welded should be no thinner than the welding electrode. It is better to cook thin metal with 1.6-2 mm electrodes. Just the welding current of 30-50 A corresponds to these parameters.
• Fourthly, in order not to burn through thin metal, it must first be welded not with a continuous seam, but with tacks, making the gap between the elements being welded as small as possible.
• Fifthly, it is very, very difficult to weld metal 0.5 mm thick using electric welding; it is best to use welding in a protective environment for these purposes.

There is another way to weld thin metal so as not to burn it. It is connected with the use of an additional electrode, which will be used as a filler material. Simply take the electrode and use it to melt with the main electrode, while placing more emphasis on it, and not on the thin metal.

In this case, it will be possible to weld thin-walled steel products without burning them.

Selecting the mode and electrodes for welding

Previously, on the site about manual arc welding mmasvarka.ru, we already talked about the inverter settings regarding the electrodes used and the thickness of the metal used. But, as they say, repetition is never a bad thing, especially when it comes to how to weld metal without burning it.

Thin metal for welding is considered to be metal whose thickness is 2.5 millimeters or less. And, as mentioned above, if welding burns through metal, then you need to use electrodes with a diameter as small as possible. Below we will present the main modes of the welding inverter and the diameter of the electrodes, depending on the thickness of the metal being welded.

Setting the inverter according to the diameter of the electrodes and the thickness of the metal is as follows:

• Metal thickness ( 0.5 mm ) - electrode diameter ( 1 mm ), welding current ( 10-20 A );
• Metal thickness ( 1 mm ) - electrode diameter ( 1-1.6 mm ), welding current ( 30-35 A );
• Metal thickness ( 1.5 mm ) - electrode diameter ( 2 mm ), welding current ( 35-45 A );
• Metal thickness ( 2 mm ) - electrode diameter ( 2.5 mm ), welding current ( 50-60 A );
• Metal thickness ( 2.5 mm ) - electrode diameter ( 2-3 mm ), welding current ( 65 A );

The data presented are approximate, because when welding with an inverter, much depends on the parameters of the electrical network itself. If it has a low voltage, then, accordingly, the current values ​​​​at the inverter will also have to be increased.

In addition to all of the above, it is worth noting another important detail when welding thin metal; it relates to the speed of movement of the electrode. To avoid burning the metal, the electrode must be moved somewhat faster than when welding thick metals.

Source: https://mmasvarka.ru/svarka-prozhigaet-metall.html

Technique for welding thin metal with an electrode: equipment features

Welding thin metal with an electrode is a difficult task that every practicing welder faces sooner or later. Such works have their own characteristics, which will be discussed in this article.

Problems of thin-walled products

The technology of welding thin metal with coated electrodes requires attention to detail and precision in work from the performer . Beginners should not start joining thin-sheet products without sufficient experience in welding elements of medium thickness. Training centers produce specialized literature that can facilitate this task.

Difficulties in work are caused by the following reasons:

1. Danger of burns . This is the most common mistake made by novice welders who cannot select the optimal operating parameters and speed of the electrode.
2. Poor welding of the seam . Another problem for inexperienced specialists, the reason for which follows from the first. Trying to avoid burns, the operator chooses the electric arc speed too high. This leads to the fact that the melt zone does not have time to warm up properly. As a result, the connection does not have the necessary strength and tightness.
3. Swells . They appear on the reverse side of the connection. It is noteworthy that on the outside of the seam there may be no visual defects, while on the opposite part of the product numerous protrusions may form, which are caused by subsidence of the molten metal under the influence of gravity.
4. Surface deformation. The metal has high thermal conductivity. The thin-sheet surface heats up very quickly, and overheating is fraught with a change in the structure at the molecular level: around the contact zone, the metal expands under the influence of temperature, while in other areas the surface is cold. As a result, the surface of the workpiece is deformed.

Selection of modes and electrodes

When welding thin-walled structures, we recommend using inverter-type devices . Compared to transformer-type units, inverters create a more stable arc, and the range of adjustment of the welding current is much higher. Additional functions, such as “anti-stick electrode”, can make work easier.

Operating parameters are set based on the thickness of the product, and the relationship is direct - the thinner the workpiece, the lower the welding current should be.

Technical reference books indicate that a thin-walled product is considered to be one whose wall thickness does not exceed 5 mm. Practice shows that certain problems begin when working with metal less than 3 mm thick.

As an example, we give the recommended cross-section of the electrode and the strength of the welding current, depending on the thickness of the workpiece:

As you can see, the ampere characteristics cannot be specified accurately, due to the differences in the characteristics of different types of metal. The optimal parameters are selected experimentally.

The function of adjusting the arc ignition mode will help to avoid burnouts in the starting area . This will allow you to start working directly in the docking area. Otherwise, we recommend igniting on a thick section and then transferring the arc to the work area.

It should be remembered that thin electrodes melt much faster than regular ones. When welding sections of equal length, the consumption of thin rods will be higher. The requirements for materials for the manufacture of electrodes do not differ from the standard requirements when performing welding work - the base of the electrode must correspond to the base surface of the product.

The right technology

To understand how to properly weld thin iron with inverters, you need to carefully study the technological chain. Its stages do not differ from the welding scheme for standard products:

1. Preliminary surface preparation.
2. Duty cycle.
3. Finishing the seam.

Let's look at each stage in more detail.

Preparation

At this stage, it is necessary to clean the connection area from traces of old paint and pockets of corrosion. After this, the surface is degreased using any available solvent. Particular attention must be paid to the installation location of the welding unit mass. Poor processing of the attachment point may disrupt contact.

Welding

The procedure for performing electric welding work is as follows:

1. Prepare the electrodes based on the thickness of the workpiece. The tip should be cleared of the flux coating to a length of 5-6 mm to facilitate ignition of the arc.
2. We recommend making point clamps along the line of the future seam at intervals of 100-120 mm. This will avoid displacement of structural elements during the work process.
3. The arc ignition process is carried out in two ways. In the first case, you need to run the rod along the surface. The movement should resemble lighting a match. An alternative is to tap the electrode on the surface. This method is used when working in hard-to-reach areas. The length of the welding arc should not exceed the cross-sectional diameter of the electrode. In this case, it will have sufficient density and stability.

1. The speed of movement of the electrode is selected individually, based on the current operating conditions. The melt zone should have a slightly elongated shape - this indicates that the metal is heated to the required depth.
2. Make sure the arc moves smoothly and avoid sudden movements. Despite the fact that modern models of welding machines are equipped with auxiliary functions, arc fluctuations can lead to weld defects.

Additional features that simplify the connection process are:

1. Arc Force . As the discharge lengthens, the operating parameters automatically increase, stabilizing the arc.
2. Anti-stick electrode . When the electrode comes into contact with the surface, the automation releases the voltage, preventing the rod from sticking.

During the work process, it is important to ensure visual control of the weld pool. In this case, the angle of inclination of the electrode should be in the range of 60-90º. As the angle of inclination decreases, the seam will have external bulges, indicating that the metal has not warmed up only on the surface.

After crystallization of the compound, it is cleaned of slag and an initial inspection is carried out for defects.

Techniques

To obtain a high-quality permanent connection, the following techniques are used:

1. Overlapping. If there is a reserve length of the products to be connected, this method will allow you to reliably connect them, due to the larger contact area. In this case, it is necessary to carefully monitor the heating of the surface to avoid burns.
2. Dots. The method avoids overheating of the surface. Used when joining particularly thin sheets. The recommended point step is three sizes of the electrode cross-section.
3. With additional electrode. In this case, it is necessary to clean the anode from the flux coating and lay it along the welding line. Places of installation are thoroughly boiled. The technology is suitable for sealing single holes.
4. Reverse polarity. The application of the method involves connecting the holder to the plus, and the mass to the minus. In this case, the surface heats up faster than the electrode, which reduces the risk of burn-through.
5. When welding metals of different thicknesses, the following method is used: the arc is ignited on a thicker element, and then it is transferred to a thinner part.

Butt welding of sheet metal is carried out in two ways:

• with flanged edges;
• lined.

In addition, it is recommended to place a copper plate to remove heat from the steel, due to its greater thermal conductivity. This allows you to avoid burn-through of products.

Basic connection methods

The technique for performing the work depends on the welding equipment and consumables used . Let us consider the features of the connection depending on the technology, with the exception of welding with consumable electrodes, which was discussed above.

Non-consumable graphite electrodes

This method has become especially widespread when working with thin-walled products by professional welders. There are two ways to achieve the goal:

• Use of filler wire;
• Melting method followed by joining.

The second method is used more often, since reflow eliminates the use of additional filler materials, which affects the cost of work. The essence of the method is to heat treat the edges being joined until the aggregate state of the surface changes. This creates conditions for joining the material. With certain skills, you can create a tight connection without burning out individual sections.

Wire is used as a filler for various cavities and voids. The size of the cross-section of the manufacturing material must correspond to the characteristics of the workpiece.

Very thin metal

This problem is most often encountered by service station workers when repairing car body parts. Modern transport manufacturers use sheets whose thickness does not exceed 0.8 mm. Thus, the use of inverter welding machines is not possible, except in emergency cases.

The main way to solve the problem is to use overlays made of thicker material, which plays the role of a frame for the future connection..

Features of working with galvanized steel

When working with galvanization, we recommend removing the protective coating manually or mechanically . Otherwise, the zinc will burn out during the joining process, which can lead to worker poisoning from its fumes.

In industrial enterprises, a directed flame is used to prepare the product, burning out the zinc layer.

Due to the insignificant thickness, experts recommend using the point connection method.

Alternative Methods

A reliable alternative to an inverter is the use of semi-automatic devices for connecting thin metal elements . The use of wire allows you to increase productivity due to the absence of pauses for replacing electrodes. The range of consumables allows you to choose the ideal option for a particular case.

The disadvantage of a semi-automatic machine is the increased requirements for the qualifications of the worker - a novice welder is not able to master all the skills of working with this equipment in a short period of time.

Conclusion

Welding thin sheet metal is a responsible process that requires certain professional skills from the performer. It is better for experienced specialists to use a semi-automatic machine - it allows you to increase work productivity and provides fine-tuning of operating parameters.

Source: https://svarka.guru/tehnika/detaley/tonkogo-metalla-elektrodom.html

Electric rivet or through-hole welding

Electric rivets are spot welds that are made with a welding arc using a consumable or non-consumable electrode. Welding in this way is widely used in industry; it is highly productive and convenient in assembling large-sized structures, for example, when covering passenger cars.

Application

Electric rivet welding is used to:

1. connect thin-sheet sheathing to frames made of rolled profiles. Since, due to the large dimensions of the structure, it is impossible to use the contact method of spot welding.
2. a connection was formed from a package of elements.
3. weld the studs.

How is welding done?

Developed by S.A. Egorov , welding with electric rivets is usually organized using a consumable steel electrode under a layer of flux. It is done in two ways.

1. In the first case, the upper part is melted by a welding arc. Used when the metal sheet is thin (less than 2 mm).
2. The second method is based on a pre-prepared hole, made by drilling or piercing.

The first method turned out to be more economical, when welding metal with electric rivets occurs without a hole in the upper part .

Also, welding with electric rivets can be carried out using a submerged steel electrode without pre-drilling a hole in the top sheet up to 12 mm thick. This becomes possible thanks to the use of a welding current of 4590 - 5000 A and the use of electrode wire with a diameter of 14 - 16 mm.

But still, welding parts with a thickness of more than 2 mm without a prepared hole is usually impractical. After all, then large welding currents and electrodes of large diameters are used, which ends in the formation of a very large electric rivet head, while the diameter of its rod is small.

If the elements are more than 2 mm thick , then the need to drill or pierce a hole leads to a limitation in the scope of application of electric riveted seams.

The use of a non-consumable electrode when welding with electric rivets allows you to create seams without reinforcement, which results in a greater depth of metal penetration compared to the use of a consumable electrode.

Sheets with a thickness of 6 mm or more can be welded with a non-consumable graphite electrode using direct current, which is used in the range from 400 - 700 A. Graphite mass of grade A, produced by the Moscow Electrode Plant, is used as an electrode material.

To protect the seam during welding, you can use flux or a variety of shielding gases.

Welding technique and modes

Electric rivets are placed with or without welding wire feeding. In the first case, the wire is directed into the welding zone, the process is completed after a given amount of wire has melted.

This occurs using a time relay or mechanical interrupter. Without wire, the process is carried out as follows: during the burning of the arc, it is not supplied, since it is fixed in the current-carrying mouthpiece.

The arc continues to burn until it naturally breaks, because its length and voltage change.

The holes are melted using an electric riveter without flux, when the current is 1800 - 2000 A.

To start the process, you need to install the electric riveter in such a way that the welding wire forms an angle of 15-20 degrees , and the end of the welding wire corresponds to the center of the future point.

  Technique for welding seams in various positions

The result of a short burning of the arc will be the splashing of molten metal by its blow onto the edge of the hole. Excess metal is removed using a chisel and hammer.

Engineer I.I. Kakhovsky made the connection using electric rivets with manual wire feeding. In order for the wire to fall smoothly as it melts, you need to guide it and at the same time quickly turn it in both directions, making movements around its axis. Its diameter can be the same and does not depend on the diameter of the hole in the upper part.

To choose a welding mode and technique, you need to consider the following points:

• Depending on the brand of flux used, its consumption and penetration depth are determined.
• Electric rivets can come in different sizes, which is affected by the wire feed speed.
• If the flux layer is small, the electric rivets swell.
• Porosity forms in electric rivets, which can be caused by rust, scale or wet flux.

Hose semi-automatic machines are useful for efficient work , because then to penetrate the top layer you will need a significantly lower amount of welding current. When they are used, the most important parameter of the welding mode is the arc burning time, which determines the quality of electric rivets. Therefore, the electrical circuit of a semi-automatic device must be based on a relay in order to dose the current flow time.

If the welding mode and technique are not followed, this can lead to defects in electric riveted joints. The reasons for their formation are:

1. When welding without wire direction, unwelded edges are obtained if the hole diameter is 1-3 mm larger than the wire diameter.
2. If the lower element is not welded, then this is possible at low current, if the diameter of the wire is small, with insufficient compression of the elements being connected, or weakening of the circuit contacts.
3. The upper part is burned through in the event of strong compression of the welding elements or when the current is increased.
4. If the welded surfaces are poorly compressed, then cracks appear in the core of the electric rivet.
5. Pores form on the surface and in the cross-section of the electric rivet from the connection of elements that are not cleaned of rust, moisture, dirt, and also if wet or contaminated flux is used.
6. A splash of metal on the surface or on the edges of the electric rivet occurs when flux clogged with slag crust is used or when the end of the wire or the current-carrying nozzle is clogged.
7. If an insufficient amount of flux is poured into the welding zone, then swelling of the head of the electric rivet occurs.
8. An electric rivet in which insufficient head height is formed is the result of a gap between the surfaces being connected.
9. An electric rivet height that is too high occurs when the flux contains many small particles, as well as when the current is insufficient for a particular wire diameter.

High performance of electric riveted joints is observed under shock and alternating loads , compared to continuous seams. On thin metal, quality control can be carried out by appearance on both sides.

• Fedor Ilyich Artyomov

Source: https://steelfactoryrus.com/elektrozaklepka-ili-svarka-cherez-otverstie/

Technique for welding thin metal with an inverter

[Welding sheets of thin metal with an inverter] allows you to quickly and efficiently produce a metal product.

Thin-sheet material is a material with a thickness of up to 5 mm; it is often used in the production of blanks for cars, motor boats, as well as for the manufacture of pipes, various hull structures, etc.

The main problem when welding thin sheets of metal is the high probability of damage.

The reason for this may be careless movement of the welder, as a result of which a burn may form on the workpiece.

In addition, welding of thin metal, carried out by a person without experience, may turn out to be of poor quality due to non-compliance with the technology.

Since the welding process is performed by an inverter exclusively using low current, even a slight gap in the working distance between the part and the electrode should not be allowed.

Otherwise, a break in the electric arc cannot be avoided. Therefore, it is not recommended to start welding thin sheets with an inverter without knowledge of the process features.

Next, we suggest that you familiarize yourself with a step-by-step lesson, specially created for novice welders, with which you can learn how to properly weld thin metal with an inverter semi-automatic machine.

Step-by-step guide to welding thin metal with an inverter

Welding thin metal requires, like any other welding process, to have protective clothing on hand: a special welding helmet, gloves and outer clothing made of rough fabric, but in no case should you wear rubber gloves.

Step one

We adjust the welding current and select an electrical conductor that will allow it to operate as an inverter.

We take the welding current indicator based on the characteristics of the metal sheets being joined.

Typically, the manufacturer indicates the current strength for specific cases on the inverter housing.

We use electrodes for inverter arc welding with a diameter of 2-5 mm. Next, insert the electrical conductor into the holder and connect the ground terminal to the workpiece.

To prevent sticking, do not bring it to the part too sharply.

Step two

Welding thin metal using an inverter machine begins with igniting the arc.

Using the electrode, we pointly touch the line to be welded a couple of times at a slight angle, which will activate it.

We keep the electrical conductor from the product to be welded at a distance that will correspond to its diameter.

Step three

If all of the above was done correctly, you should get a high-quality seam joint.

IMPORTANT TO KNOW: All about resistance welding - technology and devices

At the moment, there is scale or scale on the surface of the weld, they need to be removed using an object, for example a hammer.

The following video for novice welders will demonstrate how to properly connect thin sheets of metal with an inverter.

How to control arc gap?

The arc gap is the distance formed during welding between the elements being connected and the electrode.

It is imperative to maintain a stable size of the specified distance while operating the inverter.

If you weld thin metal with an inverter and at the same time maintain a small arc gap, then the welded seam joint will be convex for the reason that the main part of the metal does not heat up well.

If you weld thin metal with an inverter semi-automatic and at the same time keep too large a distance between the electrical conductor and the workpiece, then such a large gap can interfere with weld penetration.

The electric arc will jump, the deposited metal will lie crookedly.

A correct and stable distance will allow you to obtain a high-quality seam joint; however, it is necessary to weld thin metal with an inverter, as mentioned above, with a gap corresponding to the diameter of the electrode.

Having gained experience and the ability to control the inverter welding arc length, you will be able to achieve optimal results.

Due to the electric arc, which is fed through the gap and melts the base metal, a weld pool is formed. It also helps to move the molten metal into the weld pool.

Features of the formation of a weld seam

If you move the electrode too vigorously during the welding process, then all that can be achieved is a deformed joint.

This fact is explained by the fact that the line of the weld pool is below the level of the base metal, and if the penetration of the arc into the base metal is strong and fast, it pushes the pool back, resulting in a seam.

That is why it is necessary to control that the welding seam line is located on the surface of the metal sheets.

A high-quality seam can be achieved through circular and zigzag movements of the electrode along the surface to be joined.

When moving in a circle, it is recommended to monitor the level of the connection, distributing the weld pool as evenly as possible.

When performing zigzag actions, you need to monitor the formation of the seam line alternately in three positions: from one edge, on top of the weld pool, from the second edge.

Here we should not forget that the weld pool moves with heat, which is very important when changing the working direction.

If there is a lack of electrode metal, an undercut is formed - a narrow groove in the base metal along or along the edges of the weld, appears as a result of the lack of metal to fill the pool during transverse movement.

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To prevent the formation of such a side recess or undercut, it is recommended to monitor the outer boundaries and weld pool, and, if necessary, adjust the width of the groove.

The welding pool is operated by the force of the electric arc located at the tip of the electrical conductor.

Do not forget that when working with a welding product at an angle, the pool will not be pulled, but will be pushed.

Therefore, a vertically positioned electrical conductor allows for less convex welding joints.

The process is explained by the fact that at this time all the thermal energy is concentrated under the electrode, the weld pool is pushed to the bottom, melts and is distributed around.

When the product is slightly tilted, all the force is pushed back, causing the weld to float up.

If the electrode product is tilted too strongly, the force is transferred towards the suture line, which does not allow effective control of the bath.

To achieve a flat seam connection, the electrical conductor is tilted at different angles.

In this case, welding should begin at an angle of 450, which will make it possible to control the pool and correctly connect the metal using a semi-automatic machine.

Welding thin sheet metal with a consumable electrode

In order for the process of welding thin metal with a semi-automatic machine to be successful, it is necessary to use an electrical conductor with a suitable diameter.

For example, for sheets of thin metal with a thickness of up to 1.5 mm, you need to use products with a diameter of 1.6 mm.

Correctly welding thin metal with a consumable electrode means preventing overheating during the welding process, which can lead to burning through the product.

The electrical conductor is moved along the line to be welded at an average speed; as soon as there is a risk of combustion, the speed is increased.

The current strength during inverter welding of metal sheets should not exceed 40 Amperes.

When selecting the current strength for working with a consumable electrode, it is better to make a test weld, which will simplify the solution of the task.

In this case, a test product can be cooked semi-automatically in different modes, taking into account the speed of movement of the electrode.

It is necessary to cook in such a way that it is possible to completely ensure penetration of the steel edges without burning the material.

The peculiarity of welding thin metal with an inverter with a consumable electrode is the instantaneous melting of the edges, which does not allow full monitoring of the weld pool.

That is why it is better to start semi-automatically welding thin sheets of material after gaining experience.

In the process of welding thin-sheet metal products, spot or intermittent welding technology can be used.

Due to the short operation of the arc, tacks are formed, subsequently the electric arc is extinguished, then the process is repeated at a distance equal to the size of 2 or 3 electrode diameters.

It is better to minimize the period between creating points so that the molten metal does not have time to cool.

This method is ideal if you need to weld leaky structures made of thin sheets with an inverter. Point clamps will eliminate the possible risk of metal warping.

How to choose polarity when operating an inverter?

Polarity is the basis of a quality welded joint. Direct polarity provides a reduced heat input into the metal base with a narrow but deep melting region.

With reverse polarity, a reduced supply of thermal energy is observed in a material with a wide and shallow melting region of the base metal.

It is the polarity of the electrons that needs to be paid attention to before starting work on the inverter.

If you weld metal using direct current, you can use the positive and negative charge of the source.

But at the same time you need to know where to connect which charge.

Here it is necessary to take into account that if a positive charge is provided to the material being welded, it will become very hot.

If this charge is connected to an electrical conductor, then the electrode will become very hot and burn, which can lead to burning of the metal.

The way out of the situation is to reverse the polarity of the inverter and the optimal current indicator.

During operation of the inverter, the electrode is connected “+” to the inverter arc, and “-” to the sheet of metal.

Practical advice for beginner welders

The following few tips and thematic video material will also be useful for novice welders:

• The ability to observe the weld seam and control it from all sides during the arc welding process with an inverter will allow you to obtain a high-quality result and eliminate the formation of burnt holes;
• During the welding process, the electrical conductor must be kept as close to the workpiece as possible until a red spot begins to appear. This will mean that there is already a metal drop underneath it, due to which the metal sheets are connected;
• When the electrodes slowly move along a metal surface, hot drops of metal that appear connect segments of sheets and thereby form a welding seam.

Having studied the above information and watched the videos, it will be much easier to weld thin sheets of metal with an inverter.

Source: https://rezhemmetall.ru/svarka-tonkogo-metalla-invertorom-i-elektrodom.html

How to weld a hole in thin metal

Welding thin metal even with an inverter machine often causes certain difficulties even for experienced welders. The fact is that here you will have to be guided by completely different rules than when connecting elements of significant thickness to each other.

First of all, it should be noted that it is strictly forbidden to heat thin metal too much, as it will burn out and holes will appear in its structure. In this regard, when welding fairly thin sheets of metal, the electrode is moved as quickly as possible, without deflecting it to the side.

Another difficulty associated with welding relatively thin metal is the need to use low currents, which means that you will have to weld with a short arc. If even a slight separation occurs, the arc will go out. In some cases, difficulties arise even with ignition, so you will need to use devices with good current-voltage properties; the device should also allow smooth adjustment of the current, especially when welding with argon.

Features of welding thin metal using an inverter

A semi-automatic inverter device allows you to get the highest quality connection, which will be quite strong and durable.

If a person does not have sufficient experience in using semi-automatic welding, then it is best for him to gain some experience in the field of welding thick elements, only after that move on to joining thin metal. The fact is that the thinner the steel, the more difficult it will be to obtain a reliable seam.

The main positive characteristic of semi-automatic welding equipment is their ability to work ideally at low currents and low voltages.

The thickness of the electrodes for argon welding should not be too large - their maximum diameter will be about 2.5 mm. The inverter allows you to very quickly adjust the current strength. This is done using one handle, and the current will be in the range from 10 to 200 A. The thinner the electrode is taken and the thinner the workpieces being welded, the lower the current strength will be optimal.

Work technology

To thoroughly understand how to weld thin metal with an inverter, you first need to find out what methods of work are available. Many professionals recommend holding the electrode at a slight angle to the workpiece. The flanging method is useful here, when the edges of the parts are slightly bent and begin to be connected with the shortest seams every 10-15 cm. After the elements are fixed, you should go along the entire length of the seam from top to bottom.

Welding thin metal with an inverter often leads to the formation of burns (especially if the work is carried out without interruption). To prevent the appearance of such a defect, the arc can be torn off for one second. After this, it is returned to the same place and carried a few millimeters further. This method is more time-consuming, however, the welding of metal parts is of better quality.

The molten metal will cool down somewhat during the absence of the arc. This will be clearly visible by the change in color of the seam. The main thing in this technology is to prevent the arc from breaking off for too long, otherwise the steel will cool down too much.

If it is possible to use a spot weld, then when welding thin parts it is better to use it.

Its essence is to create small tacks at a short distance from each other, which will hold the parts in one place.

How to properly weld galvanized sheets?

Galvanized or galvanized steel is a thin sheet of metal that has been hot-dip treated with an element such as zinc during the manufacturing process. If there is a need to connect such elements, the zinc coating on the welded edges will need to be completely cleaned off. They do this in one of the following ways:

• Remove the layer mechanically - using an angle grinder and an abrasive disc, a metal brush or sandpaper;
• Burn it out by welding - zinc evaporates at a temperature of about 900 degrees, so you need to pass the electrode twice along the seam being formed. However, in this case, it must be remembered that zinc vapor is extremely toxic, so such work is allowed to be carried out either in the open air or in a room with good ventilation.

After each pass with the electrode, it is necessary to remove the flux from the surface of the workpiece. When the zinc is completely removed, the actual metal begins to be welded. To obtain the highest quality connection, you should use two types of electrodes.

To obtain a reliable welded joint, it is necessary to correctly select a parameter such as polarity, and it can be direct or reverse:

• Direct polarity ensures that the temperature is not too high, and heat will flow into the thickness of the metal into a narrow but deep area;
• Reverse polarity provides a higher temperature, and the melting region will not be too deep, but very wide.

To know how to weld thin metal, you need to choose this parameter very carefully. If you put a positive charge on the workpieces to be welded, they will heat up the most. When connecting a positive element to a conductor, the electrode will heat up too much, which can ultimately lead to burns through the workpiece.

It is advisable to use reverse polarity when connecting thin metal elements - in this case, you will be able to obtain the optimal current strength, which will allow you to monitor the formation of the weld and keep this process under direct control.

If this process is set up as correctly as possible, then in the end it will be possible to obtain a strong connection without burns through the workpiece and other defects. During the welding process, the electrode should be moved as slowly as possible.

 Then the end result will be satisfactory.

Sergey Odintsov

Source: http://ooo-asteko.ru/kak-zavarit-dyrku-v-tonkom-metalle/

Electrodes for cutting metals: brands, features, application, use with an inverter

Cutting is a technological process whose purpose is to separate various metals into workpieces of the required size and shape.

Manual and automatic tools and equipment are used to perform this procedure. However, the performer does not always have the necessary equipment. In such cases, electrodes .

For cutting, the performer, in addition to electrodes, will only need an inverter or other source of welding current .

Thus, manual arc cutting using these materials and equipment is a common type of work among professional and novice performers.

Metal cutting is used for construction and installation work at facilities for various purposes .

Due to the great popularity of processing, electrodes for cutting metal with an inverter are also in demand (see brands below).

Cutting with electrodes: pros and cons

Each method of processing materials using electrodes is characterized by its own advantages and disadvantages.

Advantages of cutting:

• convenience and simplicity of the process even for a novice performer who does not have special qualifications;
• no specialized equipment is required;
• process safety for the performer.

Disadvantages of cutting:

• cutting speed depends on the thickness of the metal being processed;
• as the thickness increases, the speed decreases significantly;
• poor quality of the resulting cut, it is characterized by unevenness and leakage;
• low performance.

Types of metal cutting

Depending on the type of cut, the following types of cutting are distinguished:

1. The separation method involves the use of an electrode whose diameter is greater than the thickness of the main product. The rod should be positioned perpendicular to the working surface and moved along the line of the future cut;
2. Surface cutting (gouging) is less popular and is used to make grooves on the surface and to remove defects. The electrode must be tilted 5-10° to the surface. Its movement is carried out with partial immersion of the rod into the cavity formed during the cutting process. To obtain a wide groove, the performer needs to make oscillatory movements with the electrode.
3. Cutting holes is a simple process: a small hole is made in the metal, which is then gradually expanded to the required size. In this case, the electrode is located almost perpendicular to the surface, only small deviations are allowed.

Electrodes for cutting metals: types, advantages and disadvantages

1. Metal electrodes for manual arc cutting of metal with a special coating. These materials improve the quality of the cut. The composition of the coating allows you to make the work process comfortable, as well as:

• prevent the transition of the arc to the side surfaces of the cut;
• ensure the stability of the arc and eliminate the possibility of its extinguishing;
• promote oxidation of the metal at the cutting site and create gas pressure at the melting site .

For your information! The cutting process is performed at increased current values; the type of voltage depends on the brand of electrodes used.

Differences between electrodes for cutting and conventional ones for welding: high thermal power of the arc; high heat resistance of the coating; intense oxidation of liquid metal.

It is advisable to use metal consumables for removing defective seams, tacks, rivets, bolts, and cutting cracks.

It is recommended to calcinate welding materials for 1 hour at a temperature of 170°C, unless otherwise indicated on the packaging

It is also worth noting that conventional welding electrodes are also suitable for manual arc cutting of metal . To carry out the work, you only need to increase the current indicator by 30-40%; the type of voltage depends on the brand of consumables used.

However, there are several disadvantages of using conventional rods:

• increased consumption of electrodes and electricity;
• The coating of some rods is not intended for operation in such modes; the coating melts and flows into the working area. This makes it difficult to obtain a quality cut.

Therefore, it is recommended to use specialized cutting electrodes.

We invite you to watch a video where Uncle Gena, a well-known welder on YouTube, tests the Zeller 880AS brand:

2. The working process using carbon (graphite) electrodes is practically no different from cutting using metal rods. The electric arc completely melts the metal and it flows down under the influence of gravity. However, there are some differences: coal consumables do not melt, but gradually burn out . This reduces the amount of molten metal and slag. Those. the cut is cleaner .

Another advantage of carbon consumables is that they are able to
heat up to high temperatures at low current values. At the same time, the melting temperature of the rods is quite high and exceeds 3800°C, which ensures durability and cost-effectiveness of using these materials.

Carbon (graphite) electrodes are used for manual arc and oxygen-arc cutting.

Cutting is carried out using direct current of straight polarity, “from top to bottom”. It is also possible to use alternating current.

3. Tubular electrodes are designed for oxygen-arc cutting. The main difference between these materials is that the melting element is not a welding wire, but a hollow thick-walled tube. The essence of the process includes several stages:

• the arc is excited between the electrode and the workpiece;
• metal melts under the influence of an electric arc;
• oxygen coming from the tube oxidizes the metal throughout its thickness and blows it out.

The main disadvantage of this type of procedure is that the oxygen flow negatively affects the stability of the arc.

4. Tungsten non-consumable electrodes are used for shielded arc cutting and plasma arc cutting.

The essence of the first method is that for cutting, an increased current value is set (about 20-30% more than during welding) and the metal is melted throughout its entire thickness.

Plasma arc cutting involves exciting an arc between the metal being processed and a tungsten electrode.

The process of cutting metal using electrodes

Since the manual arc method of cutting metals using special electrodes and an inverter is the most popular, let’s consider the main stages of this work process:

• preliminary preparation includes checking the serviceability of the cables used;
• the arc is ignited by tapping or striking the electrode on the metal surface;
• The current on the inverter is set based on the diameter of the electrode, the thickness of the metal being cut and the type of cut:
  • thin metal should be cut with a rod with a diameter of 3 mm;
  • for metal of greater thickness - 4 or 5 mm.

Important! When cutting thin metal, the current should be increased (up to twice as high as usual).

A very good video where you can clearly see and learn this simple operation.

By following these recommendations and correctly setting important cutting parameters, you can quickly and easily master metal processing techniques.

Below are brands of special electrodes for cutting and gouging metals.

ROTEX R electrodes are designed to perform the following work: metal cutting, incl. and rod reinforcement up to 40 mm; cutting, gouging and

Further "

OZR-2 electrodes are designed to perform the following work: cutting and gouging of rod reinforcement; cutting and piercing

Further "

OZR-1 electrodes are used for the following work: cutting, gouging and piercing holes; removing defective areas of welded joints

Next » Choose manufacturers and sellers of welding electrodes by clicking on the link below to the page of our catalog of companies.

Select a company

Source: https://WeldElec.com/naznachenie-elektrodov/dlya-rezki-metalla/

How to cut with electric welding

Every beginner and even an experienced welder burned through metal while welding. This is either due to a large current, or due to a very thin sheet, or due to both. Metal cutting is carried out using this property. It is most convenient to cut a sheet or product using manual arc welding, that is, an electrode.

Electric welding, of course, cannot cut metal like plasma, laser or grinder, but such cutting still exists and is used quite widely. It is mainly used where very precise cutting of metal .

Cut off, for example, an extra piece of reinforcement or stainless steel. For such cutting, nothing is needed except electrodes and a welding machine. You can cut very thin and thick materials; the thickness of the metal being cut depends on the current strength.

If you have a powerful device and strong electrical wiring, you can cut until the electrode in the holder melts.

Cutting thin and thick sheets occurs slightly differently. When cutting thin metal, the current increases, approximately twice as much as usual. The electrode should be closer to the workpiece and go deeper into the cut. It is as if excess metal is blown off by welding. Everyone can do this.

But getting the cut edges to be relatively straight takes practice. Thick sheets are cut almost the same way. The current is added depending on the thickness you want to cut. When cutting, you will need to blow through more thickness.

To do this, you will need to deepen the electrode into the molten metal, pushing it out until you can see that it has been cut all the way through.

When cutting metal by electric welding, old, unnecessary electrodes of the required diameter are usually used. If you are cutting thin metal, then an electrode with a diameter of 3 mm or three is quite suitable for you, and for a thicker sheet a four or five is required.

Plasma cutting services for various metals, as well as their alloys, are very popular. Plasma cutting makes it easy to cut stainless, carbon and high-alloy steel. We also often accept orders for plasma cutting of titanium, aluminum, brass, copper, bronze, cast iron and products that combine several types of alloys.

Excellent quality and fast order fulfillment are guaranteed by many companies providing similar services.

Metalworking services are also provided, and a wide range of metal products are produced according to customer drawings with the necessary equipment and a staff of craftsmen, whose qualifications allow us to fulfill orders at the highest level of quality in a short time.

When making or repairing metal products, it is often necessary to cut metal. Depending on the design and thickness of the parts, different methods can be used, but one of the universal ones is the air-arc cutting method, based on the use of ordinary welding equipment.

To do this, you only need to exceed the value of the welding current, and instead of forming a weld pool and seam, burn a hole due to the intensive melting of the metals of the electrode with the part.

For cutting metal

In the future, using the position of the electrode, you can successfully cut steel. Molten metal is removed from the cut site by arc pressure and its own weight. Sometimes it is additionally blown out with a stream of air.

In this way, by exceeding the welding current by up to 30% and using ordinary welding electrodes, metal parts can be cut. True, the quality of the resulting walls will be low, and the edges will be melted and covered with slag. For further use, they will have to be processed with mechanical tools. But in many cases this is simply not required.

The arc cutting method can be used when placing a part in different planes. This is convenient when performing installation and repair work.

If it is necessary to improve the conditions for the flow of metal from the cut site, then after orienting the position of the part in space, a second welding cable is used to create a magnetic field that deflects the position of the arc. An additional cable is attached to the top near the beginning of the cut.

It is convenient to cut parts in this way from the edge or cut hole. The angle of inclination of the electrode is selected depending on the thickness of the metal being cut. It is convenient to process thin sheets at a right angle of inclination, while sharp angles are suitable for thick parts.

If you place the electrode at an acute angle of up to 20 degrees, you can melt grooves in the metal. To do this, move the end of the electrode immersed in the metal and create small vibrations in the vertical direction. By varying the speed of movement of the arc with the angle of inclination, you can choose the depth of the groove. It is quite acceptable to make several passes to increase it.

If it is necessary to burn round holes, the electrode is placed at right angles to the surface and an arc of maximum length is created. If you need to increase the size of the hole, then step back from its edge and expand the slot in a circular motion.

Conventional electrodes burn out very quickly during such work. Therefore, for long-term use, special electrodes for metal cutting are produced, which allow better cutting of cast iron, steel of all grades and non-ferrous metals. The OZR-1 and OZR-2 brands have universal qualities and are popular. Their operational capabilities have been assessed by many experts.

You can cut metal using arc welding using different electrodes; each welder independently chooses the brands that suit him best. But a good craftsman always has specially manufactured and tested electrodes in stock for high-quality performance of important work.

Optimal welding current and electrode position. Welding cutting. (10+)

Self-instruction manual for a novice welder - Welding current. Electrode position. Metal cutting by welding

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Welding current

What about welding current? As you, I hope, have already understood, the higher the welding current, the more energy is transferred to the welding zone, the stronger and deeper the metal melts and the thicker the products you can join. And to transmit a greater current, a thicker conductor is needed. Accordingly, we can reach a direct relationship: metal thickness - electrode thickness - current strength.

Welding machines are often marked with signs corresponding to the thickness of the electrode and the welding current. I recommend that you do not take such tables as dogma - they are just a starting point to guide you. For household use, a current of up to 160A is sufficient, which allows you to use a 4 mm electrode. In my memory, I very rarely used this diameter of electrodes.

Basically it is 2 and 3 mm. There is also a diameter of 2.5 mm for electrodes of the UONI-13/45, 15/55, NIAT-3M brands (types for carbon steels). Approximately the strength of the welding current can be determined by the formula: I=Kdel.

Where K is an experimental coefficient equal to 40-60 mm for electrodes made of low-carbon steel and 35-40 mm for electrodes with a rod made of high-alloy steel, and del is the diameter of your electrode.

Metal thickness, mm	2	3	4 — 5	4 — 5	5 — 10	5 — 10
Electrode diameter, mm	2	3	3	4	4	5
Welding current strength, A	40 — 80	80 — 120	100 — 150	160 — 200	160 — 210	180 or more

Metal cutting by welding, welding machine, burning

Now let's speculate - what happens if we take an electrode with a diameter of 2 mm for a sheet of steel 2 mm, and set the current to about 100A, which usually corresponds to an electrode diameter of 3 mm? What will happen is that the electrode and steel will begin to actively melt and evaporate. The electrode will have to be supplied very intensively to the welding zone. You won't get any bath, but you will get the so-called. through burning.

It seems like a nuisance, but let’s turn it into a good thing - we’ll start moving the electrode progressively, controlling the occurrence of burnout. And lo and behold, we cut steel! Moreover, in this way you can cut a fairly thick-walled sheet. Of course, the quality of the edges will be much lower than when cutting with an angle grinder (grinder), but this method is sometimes quite applicable when high demands on the quality of the edges are not made.

The current for cutting metal is usually 25-30% higher than the current required for welding.

Electrode position during welding. Electrode holder, holder

You insert the electrode into an electrode holder (welders call it a 'holder'). It should be comfortable, lightweight, and have grooves for installing the electrode at different angles. There are many different electrode holders in design and application.

As a rule, well-known manufacturers equip welding machines with quite decent electrode holders, and you do not need to think about their modifications. When you insert the electrode into the holder, be sure to check (by rocking) that it is securely fastened in the holder.

Otherwise, sparking will occur at the attachment point and your arc will either be unstable or not ignite at all.

So how do we hold the electrode? In relation to the seam plane, it can be at an angle of 30-60° from the vertical, or at a right angle. When making vertical seams from bottom to top, the angle should be 45-50° down from the horizontal. If from top to bottom - 10-20° down from the horizontal. In addition, the process is determined by the direction of movement.

When welding at an angle 'forward' (away from you), the depth of penetration decreases, the height of the convexity of the seam decreases, but the width of the seam noticeably increases, which makes it possible to recommend this position for joining metals of small thickness. In this case, the melt and slag moves ahead of the electrode. This method has a number of disadvantages - for example, a lot of liquid slag accumulates in front of the electrode, it flows onto the metal and interferes with maintaining the arc.

Lack of penetration and slag inclusions are possible. In this case, it is necessary to align the position of the electrode to vertical.

Generally speaking, you will observe how the metal flow and arc 'repel' the melt in the weld puddle and will observe differences at different electrode positions.

'Right angle' welding (the electrode moves away from you) allows the liquid slag to follow the weld pool, covering the liquid weld metal just behind the electrode. This ensures the formation of a high-quality roller.

In addition, when welding with rutile-coated electrodes, the inclination of the electrode towards the future weld should always be greater than for electrodes with a basic coating.

The most common way is ' backward angle '.

When welding 'back angle', the penetration depth and the height of the convex increase, but the width decreases. Heating of the edges is insufficient, so failure of fusion and formation of pores are possible. If the electrode is tilted excessively, you will see how, under the influence of the arc, the slag is pushed out of the bath, exposing the metal.

cut metal using electric welding

This causes the weld metal to cool quickly. This negatively affects the quality of the seam. The seam is uneven, with scales and significant differences along the edges to the base metal. It is necessary to maintain such an angle that the liquid slag follows directly behind the electrode and is not displaced by the arc force.

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Why does metal burn through when welding with an inverter?

» Articles » Why metal is burned through when welding with an inverter

Welding thin metal with an electrode allows you to assemble lightweight structures with a large margin of safety. This method can also be used to restore cars and repair many other thin-walled products. However, this process is quite complicated; it is very difficult to make a high-quality weld without experience.

In this material we will analyze all the nuances of welding work on thin sheet metal, what problems there are and ways to avoid them.

Problems of welding thin-walled products

The main problems that arise in the process of welding thin metal with electrodes are similar to ordinary defects due to poor-quality connections.

• Burning the workpiece.
• Electrode sticking.
• Unwelded seam.
• Material deformation.

Burning is the most common phenomenon when working with thin-walled structures. This is a consequence of incorrectly selected current strength. It is the excess power that contributes to the rapid melting of the metal and the formation of holes.

Electrode sticking occurs in two cases: at low current and when the tip of the consumable is brought close to the metal surface. These two negative factors contribute to the formation of an uneven joint and, as a result, the quality of welding decreases.

An underwelded seam is a common mistake made by beginners in welding. For fear of burning through the metal, the tip of the electrode is removed a long distance and the melt simply spreads over the surface. As a result, during stripping it turns out that the seam is uneven and there are areas that are not connected.

Deformation is also a fairly common occurrence when welding thin sheet metal. This is a consequence of exposure to high temperatures.

How is welding of thin metal carried out and what are the ways to solve the problem of defects?

Welding techniques for thin-walled structures

To avoid negative consequences during the welding process, you can use some suitable techniques.

Overlapping. If the design allows, the sheets can be placed one on top of the other. In this case, the main thing is not to burn the surface located below.

Point connection. Technologically, such a seam is made in the form of local tacks. The arc is ignited, the metal is boiled in the right place and extinguished. And then, throughout the entire connection, in increments of 3 electrode diameters, everything is repeated.

By electrode. If there is a danger of burning through thin metal, you can clean one electrode of the coating and lay it along the future seam. During the welding process, these places need to be thoroughly boiled. You can weld burnt holes in the same way.

Also, for welding thin-walled structures, reverse polarity can be set. When the holder cable is set to positive and the ground to negative. Reversing the polarity reduces the amount of heat at the electrode tip and will help avoid burn-through.

If you need to weld a massive part with thin metal, then the arc is ignited on a thick-walled workpiece and in the process the weld is transferred to the joint.

To remove excess heat, a copper strip can be placed under the thinnest parts. Copper is a very heat-intensive material and will avoid burning and leakage of molten metal.

What do you think about this type of work, such as welding of thin sheet metal? If you have extensive experience in welding joints made of thin material, share it in the comments to this article.

wikimetall.ru

Thin metal inverter welding technology

: 58

• The role of experience in inverter welding
• Welding thin metal with an inverter: advice from experienced craftsmen
• Selection of electrodes for welding thin metal
• Some conclusions for those wishing to master thin metal welding

Since the advent of welding inverters, welding has ceased to be the domain of exclusively professionals. Old devices were quite difficult to use, both because of their weight (mainly due to old transformers) and the complexity of their operation.

The inverter is distinguished by its extreme simplicity and ease, and even a beginner can work with it, who just needs to familiarize themselves with a number of rules and tips and watch a few video tutorials.

But, as in every business, the experience gained with an inverter will never be in vain.

Cooking with an inverter, unlike other welding machines, is simple and easy.

There are certain tasks that are not at all easy for an inexperienced welder to solve - these include, for example, welding thin metal with an inverter. This is difficult to do for a number of reasons, but the main one is that it is very difficult for an inexperienced welder to select the strength of the current and the impact on the metal in such a way as not to burn through it where it is necessary to connect.

Thus, welding thin metal requires certain skills and attention to detail, each of which can increase the chance of getting it done well.

Welding diagram using an electrode.

Welding with an inverter is always a balancing act between two extremes: burning through a metal part and the electrode sticking to it. That is, depending on the distance between the electrode and the surface to be welded, on the current used during welding, on the speed of movement of the electrode and its smoothness, the efficiency of welding and its result depend.

So no matter how much the inverter makes the life of welders easier, welding thin metal is a sufficient obstacle to his inexperience. Experienced welders, in addition to knowing many small nuances of welding that help them do their work more delicately and better, also have a trained hand, experience, and an eye.

And they make up at least half of the success in such work.

An inexperienced welder will not be able to quickly and reliably select the current strength in the inverter so that, on the one hand, he does not burn through the sheets of metal, and on the other, he connects them reliably.

Welding thin metal with an inverter is too much of a challenge for beginners and even experienced welders, and they prefer to use argon arc pulse welding. In this case, the risk of metal burning is reduced to extremely low values, and the seam remaining at the joint will be smooth and beautiful.

But sometimes you have to weld with an inverter, even on thin sheets of metal, and therefore it is better to increase the chance of a good job by reading some advice from experienced welders.

Return

Straight polarity diagram.

Source: https://samsvar.ru/stati/pochemu-pri-svarke-invertorom-prozhigaetsya-metall.html

How to burn a hole in metal yourself using electric welding?

Reading time: 4 minutes

When we need to make a hole (or, more correctly, a hole) in metal, we use a regular drill and metal drills. However, this method is not always convenient and simple if you need to make a hole of large diameter. In this case, a welding machine and an electrode will help. With its help you can burn a hole of any diameter, even in thick metal. In this article we will briefly explain how to cut metal using electric welding technology.

general information

Many home craftsmen are accustomed to thinking that welding should be used only when two metal workpieces need to be connected. However, having a welding inverter and electrodes in your hands, you can perform not only welding, but also metal cutting. This technology is useful if you need to make a hole in a workpiece.

You don't need to be a professional to make a hole in metal with an electrode. It is enough to know the operating principle of the inverter and be able to apply it in practice. The cutting process is simpler and faster than welding, since there are no such high requirements for the quality of the seam. With practice, you can achieve a fairly smooth cut with neat edges. Therefore, cutting is suitable even for those who have never used a welding inverter.

What should you have on hand?

To make a hole in metal, you must have an inverter, electrodes, as well as a hammer and a brush with metal bristles.

Inverters come in different types: cheap and expensive, professional and household, powerful and not very powerful. In essence, it does not matter which inverter you use for cutting. The main thing is that it is in good order.

As for electrodes, there is a wide choice. Previously, cutting was performed with the same electrodes as welding. But now there are many brands on sale that are designed specifically for cutting. They are all good in their own way. The most popular brand of cutting electrodes is OZR. They provide a more or less even cut and allow you to get the job done quite quickly.

If you decide to use conventional electrodes for welding, then be prepared that the cut will not be the most aesthetically pleasing, and the work itself will proceed more slowly, and the arc will burn unstably.

Source: https://svarkaed.ru/svarka/poleznaya-informatsiya/kak-samostoyatelno-prozhech-otverstie-v-metalle-elektrosvarkoj.html

How to weld thin metal

Welding thin metal is a challenge even for some experienced welders. Beginners in welding generally have a hard time. The rules that apply here are completely different from those when welding thick products: there are many features and difficulties, which makes it more difficult to select modes and electrodes. It’s easier to do this with semi-automatic welding machines, but they are quite rare in everyday life; inverters are much more common. We will talk about welding thin metal with an inverter.  

And the first difficulty when welding metal of small thickness is that you cannot heat it too much: it will burn out and holes will form. Therefore, they work according to the principle “the faster, the better” and there is no talk of any trajectories of electrode movement at all. Thin sheet metal is welded by passing the electrode in one direction - along the seam without any deviations.

When welding thin metals, the sheets overheat and bend

The second difficulty is that you need to work at low currents, and this leads to the fact that the arc has to be short. With a slight separation, it simply goes out. There may also be problems with arc ignition, so use devices with a good current-voltage characteristic (no-load voltage above 70 V) and smooth adjustment of the welding current, which starts from 10 A.

Another trouble: with strong heating, the geometry of thin sheets changes: they bend in waves. It is very difficult to get rid of this shortcoming. The only option is to try not to overheat or remove heat (read about the method with heat-dissipating pads below).

When butt welding thin sheets of metal, their edges are carefully processed and cleaned. The presence of dirt and rust will make welding even more problematic. Therefore, carefully align and clean everything. The sheets are placed very close to one another - without a gap. The parts are fixed with clamps, clamps and other devices. Then the parts are tacked every 7-10 cm with short seams - tacks. They will prevent the parts from shifting and are less likely to bend.

If you clean the edges well, you can get a good seam

How to weld thin metal with an inverter

Welding machines that produce direct current are good because we can weld with reverse polarity. To do this, we connect the cable with the electrode holder to “+”, and connect “-” to the part. With this connection, the electrode heats up more, and the metal heats up minimally.

Read about how to choose a welding inverter for your home or cottage here. 

It is necessary to cook using the thinnest electrodes: from 1.5 mm to 2 mm. In this case, you need to choose one with a high melting coefficient: then even at low currents the seam will be of high quality. The current is set to small. For electrodes measuring 1.5 mm it should be about 30-45 amperes, for a “two” - 40-60 amperes. In fact, sometimes they put it lower: it is important that you can work.

Metal thickness, mm0.5 mm1.0 mm1.5 mm2.0 mm2.5 mm

Electrode diameter, mm	1.0 mm	1.6 mm - 2 mm	2 mm	2.0 mm - 2.5 mm	3 mm
Current strength, A	10-20 amps	30-35 amps	35-45 mm	50-65 mm	65-100 mm

To ensure that the metal heats up less, the parts are placed in a vertical or at least inclined direction. Then they cook from top to bottom, moving the tip of the electrode strictly in this direction (without deflecting or returning). The tilt angle is forward, and its value is 30-40°. This way, the heating of the metal will be minimal, and this is one of the most important tasks for welding thin metals.

Electrode positions for welding and their use

General recommendation for choosing electrodes for welding thin metals: buy high-quality imported electrodes for such work. There will be many fewer problems.

Read about making a shed on a metal frame here. 

Techniques and methods for welding thin sheet metals

Sometimes thin sheets need to be welded at an angle. In this case, it is more convenient to use the flanging method: the edges of the sheet are bent to the required angle, fastened with short transverse seams every 5-10 cm. Then they are welded as mentioned above: with a continuous seam from top to bottom.

The video shows how to weld thin sheet metal with an electrode using a welding inverter. The flanging method is used: the edges of the parts are bent, then secured in several places with short seams. This is followed by welding with a thin electrode 2 mm thick.

Source: https://stroychik.ru/tools/svarka-tonkogo-metalla