What is an inverter welder

My secret

Instruction

Pick up on each other.
The grapple is made by short jumpers (about 5-10 mm) with a distance between them 50-100 mm everywhere in the intersection. With a periodic interrupt - watch the arc (pull out the electrode) and light it again so that the metal does not have time to cool. The time of continuous burning of the arc depends on the thickness of the blade and the current force. For a sheet 1mm thick and thinner, it should be 1-3 seconds.

Cook the leaves completely
Cream the joint with an intermittent suture, from time to time to move the electrode to a new (cold) junction area. This avoids severe metal distortion - especially if the specified length is relatively large (more than 200-250 mm). The smaller the length of the continuous seam, the smaller the heating. Start cooking from one edge of the intersection and then move to another edge, then drag to the center, etc.

Welding fine metal bushing
Get the minimal gap between the edges of the steel along the entire length of the intersection. An ideal case is the complete absence of a gap. To weld fine metal, use the auxiliary chuck stacked under the joint. Cooking a thin (1mm and thinner) Jack stool without a lining is quite difficult, although with the presence of welding and good (imported) electrodes it is quite possible. The technology of welding itself (selection of welding current, use of gripper, intermittentness and step resistance of welding) remains exactly the same as when welding the mustache.

Welding with steel uniform lining
If the design of the part allows the presence of a uniform lining, then tuck the strip under the hinge steel of the same thickness as the main sheet, 13-15 mm wide. Take care of their welded metal. Such a feed will allow you to cook the item, even if there are several millimeters of several millimeters in the intersection. The lining in this case is welded to the part.

A large number of devices and welding methods are used to connect metal parts. However, when it comes to connecting thin (less than 2 mm) billets, not all methods and devices are suitable. Such a metal is also called "thin". It is used in many fields, e.g. B .:

  • automotive, shipbuilding, air and rail transport;
  • all kinds of corpus structures;
  • test parts of buildings

Welding the thin metal has not bypassed the side of home masters and craftsmen. Due to the fact that the welding inverters have acquired a fairly widespread consideration in everyday life, a reasonable question arises: is it possible to weld a thin metal at home using an inverter welding machine? In this article we will try to figure out how to correctly cook the metal electrode, learn about the subtleties and nuances of this process.

If you are inexperienced in welding thin metal, it is better to read the technology and features first. Before welding parts, you need to practice on unnecessary residue or on a broken space. Then it is seen how the melting metal of the electrode behaves and how the arc holds. Only a small current is used with inverter welding as it is not possible to break the working gap between the electrode and the workpiece. For every type of welding you need protective equipment and clothing: leather-heat-resistant gloves, coarse, non-flammable clothing, welding helmet or glasses, preferably boots with thick rubber soles.

Sequence of work that was carried out when welding the inverter

Preparation for work.

How to cook a thin metal inverter do not know everything. Therefore, a step-by-step instructional instruction for beginners in it describes the sequence of operation when welding with an electric arc welding of fine metal:

  1. We select the electrode and the size of the welding current. Often times, the power of the current for different thicknesses of the metal is written on the housing of the welding machine. The optimal value is 35-40 A. Select electrodes for welding thin metal according to the table
  2. Now place the selected electrode in the holder, clamp the ground clamps on the processed workpiece.
  3. It is important to terminate that the welded parts fit tightly together.

Process of work

  1. Welding begins with the point tape electrode for fine metal welding over the edges, then the point is made in the center of the future seam. So the metal does not have time to warm up, and the internal stress is evenly distributed. Points are carried out by short movements.
  2. After each use, the welding area must be cleaned with a metal brush to remove traces of slag.
  3. The process of applying dots continues until they overlap as the seam tightens. It is important not to rush and cool the metal after each passage after the points, then the metal will not violate cables and the geometry of the product.
  4. After the spot seam has become tight, it is possible to go through with a tight seam with a tight seam on a very short arc with a joy electrode on the coating and be required quite quickly.

Experienced welders recommend the welded surface relative to the horizon and run the weld from the bottom up. The seam must be "pulling", in this case the slag will be emptied and bleed with the pressure of the welding arc.

The main disadvantage with welding thin film metal products is the greater likelihood that movement, deformation, and damage to the metal are more likely. The main reason, the unnecessary work of the welder and, later, spoiled product.

From all of the above, the conclusion is that high-quality arc welding of the electrode of thin metal sheets can only be with a thorough study of the characteristics of the process and properly selected equipment. It is possible to make the desired arc for welding, just an experienced welder who has already stuffed and found the required current value.

By welding thin sheet metal inverters, you can make a metal product quickly and efficiently.

The thin sheet is a material up to 5mm thick, it is widely used in the manufacture of blanks for cars, motor boats, as well as in the manufacture of pipes, various cabinet structures, etc.

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

The reason for this may be the careless movement of the welder, as a result of which the processed details can be formed by burning.

In addition, thin metal welding performed by an inexperienced person can turn out to be of poor quality due to non-compliance with technology.

Since the welding operation is carried out with only a small current by an inverter, it is impossible to allow even a slight interruption in the working distance between the part and the electrode.

Otherwise you won't avoid the cliff of electrical arge. Therefore, it is not recommended to weld thin sheets in an inverter without knowing the characteristics of the process.

Sweet metal welding, like any other welding process, requires protective clothing on hand: a special welding helmet, gloves and upper chicks made from a coarse cloth, but in no case should the rubber gloves be put on.

Step one

We use the welding current and select a wiring that will operate the inverter.

The indicator of the welding current takes the basis of the properties of the connected sheets.

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

Electrodes for inverter arc welding with a diameter of 2-5 mm. Continue to insert the electrical direction into the holder, connect the ground clamping with the processing of the part.

In order not to stick, it is not necessary to bring it too tightly to the details.

Step two

Welding fine metal to the inverter device begins with arc ignition.

The electrode is a few times in a smaller line at a small angle, which allows you to activate it.

Keep the electrical conductor from the welded product at a distance equal to its diameter.

Step third.

If all of the above has been done correctly, then it should be a qualitative suture mass.

At the moment there is a scale or ruler on the surface of the weld, it must be removed using some kind of object, for example, a hammer.

The next video for novice welders shows how to properly match the inverter of thin sheet metal.

How To Control The ARC Gap?

The arc gap is a distance that forms between the connected elements and the electrode during welding.

Mandatory in the process of the operating converter must maintain a stable size of the specified distance.

If you cook a thin metal inverter while holding a small arched gap, the welded seam will be convex because the main part of the metal is heated strongly.

If you semi-automatically cook a thin metal inverter and keep it too large between the electrical conductor and the workpiece, such a high period can be an obstacle for the provider.

The electric arc will jump, the weld metal will go to bed.

The correct and stable stretch will allow you to get a high quality suture, while requiring a thin metal inverter, as mentioned above, with a gap equal to the diameter of the electrode.

Having acquired the experience and ability to control the inverter length of the welding arc, it is possible to achieve optimal results.

A weld pool is formed due to the electric arc delivered through the gap, which cleans the main metal. This also moves the molten metal into the weld pool.

Features of the formation of the weld

If the electrode moves too intensely during the welding process, then all that can be achieved is a deformed joint.

This fact is explained by the fact that the weld pool line is below the level of the main metal, and when the penetration of the arc in the main metal is strong and rapid, the bath appears back, thereby the seam appears.

Therefore it is necessary to control the weld groove line on the surface of sheet metal.

A qualitative seam can be achieved by circular and zigzag movements of the electrode along the connected surface.

With zigzag actions, it is necessary to monitor the formation of the seam line alternately in three positions: from one edge, on the weld pool, from the second edge.

Here you shouldn't forget that the weld pool is moving for heat, which is very important when changing the direction of work.

With a lack of metal metal, a substrate is formed - a narrow groove was formed mainly metal along or along the edges of the weld, it appears as the result of a lack of metal to fill the bathroom with lateral movement.

To eliminate the formation of such a lateral depression or subsidy, it is recommended to monitor the outer boundaries and, if necessary, a weld pool, monitor the width of the grooves.

Operate the weld pool allowing the force of an electric arc at the top of the electrical ducting.

Do not forget that when working with a welding product, the bath will not reach and squeeze at an angle.

Therefore, the vertically arranged electrical capital enables less convex welded joints to be obtained.

The process is explained by the fact that at this point the weld pool is concentrated in the electrode at this point, deflecting the weld pool to the ground, melting it and spreading it.

With the product in a slightly inclined position, all of the force is adjusted back by the fact that the weld seam emerges.

With too much an inclination of the electrode product, the force is transmitted in the direction of the seam line, which does not allow to effectively control the bathroom.

To achieve a flat mass of the seam, the slopes of the electrical conductors are used at different angles.

At the same time, the welding should start at an angle of 450, which will allow the bath to be controlled and properly maintained with a semi-automatic mixture.

Sweet metal welding with melting electrode

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

For example, for thin sheets up to 1.5mm thick, it is necessary to use products 1.6mm in diameter.

Correctly cut a thin metal with a melting electrode - it means preventing overheating in the process of welding, which can lead to a burn in the product.

The electric conductor is moved along the welded line at a single stroke as soon as the risk of burns is raised - the speed is increased.

The power of the current with inverter welding plates made of metal should not exceed 40 amperes.

Choosing the current strength for work through a melting electrode, it is better to conduct a test welding of the seam, which will simplify the solution of the task.

At the same time, with a test product it is possible to carry out a semi-automatic in different modes, taking into account the speed of movement of the electrode.

You need to cook in such a way that it is possible to fully ensure the supply of steel edges and not to burn the material.

The peculiarity of welding a thin metal inverter with a melting electrode is the momentary melting of the edges, which does not allow the weld pool to be fully monitored.

That is why it is better to cook a semi-automatic material that has received experience.

In the process of welding thin metal products, point or intermittent welding technology can be applied.

At the expense of the short operation of the arc, the ribbon is formed, the electric arc is quenched, then the procedure is repeated at a distance that is the size of 2 or 3 diameters of the electrode.

The time between creating points is better to minimize the molten metal not having time to cool.

This method is ideal when you need to boil the inverter with leaks from fine leaves. Point grips eliminate the potential risk of metal warpage.

How to choose polarity on the work converter?

Polarity is the basis of a high quality welding joint. Direct polarity ensures reduced heat intake for metal with a narrow but deep melting range.

With a reverse polarity, a reduced flow of heat energy is observed with a wide and not deep melting range of the base metal into the material.

It is the polarity of electrons that need to be careful before starting working inverter.

If you are cooking metal on constant current, then you can use the plus and minus digits of the source.

At the same time, however, you need to know where to connect.

Here you need to take into account whether there is a positive charge in welding the material to ensure that it is very hot.

When this charge is connected to the electrical conductor, the electrode will be very hot and will burn, which can lead to a metal fire.

The output from the situation is the reverse polarity of the inverter and the optimal current of the current.

In the process of the operational converter, the electrode with the inverter arc "+" is connected to the metal sheet "+".

Several of the following tips and thematic video material will also be useful to encourage welders:

  • The ability to observe the weld and control it from all sides in the process of the ARC welding inverter makes it possible to obtain a qualitative result and exclude the formation of corporate holes;
  • When welding, the electrical direction must be kept as close to the product as long as the red-colored language appears.This means that there is already a metal drop underneath, through which the connection of sheet metal sheets is carried out;
  • As the electrodes move slowly along the metal surface, the recovery waste of metal joins the segments of the blades, thereby creating a weld.

After examining the above information and seeing video footage, welding thin sheets of metal inverters will be much easier.

The further, the more vehicles, technical devices and structures are carried out with fine metal. These are cars, boats, profile pipes, wall covering and much more. Since no surface is insured against mechanical damage, the wider thin metal becomes the common type of repair.

Views

All types of welding are divided into three broad categories:

  • thermal-
  • thermomechanical.
  • mechanically;

The first is due to the melting with thermal energy, with the second in addition to thermal energy, it prints in the third case pressure and mechanical energy pressure.

Heat welding are of a few types, depending on the heat source - electric arc, gas torch, plasmadet, laser beam, etc. For a fine metal, all of the electrical arm welding is used, less often gas.

Again, the electric arc is also of several types: an incompatible electrode (non-metallic rod or refractory metal) or fusible electrode; Use of direct or alternating current; Open bow (in air), under the flow (using a protective substance) in an inert gas. Tungsten (uncompensated) TIG electrode (tungsten inert gas abbreviation / inert gas) is used for thin sheet metal. Its main drawbacks: firstly, dependence on the electrical network, secondly, in order to avoid metal burns, the welder must have the equipment perfectly.

Several easier to perform welding on MIG / MAG technology, semi-automatic melting electrode (wire), but also requires mastering skills. TIG advantages: compactness of equipment, narrow thermal exposure zone and, as a result, more accurate seams. The same can be said about semi-automatic mode. Main disadvantage of semi-automatic: they are more expensive than equipment for TIG.

Gas welding (usually acetylan-oxygen) is much easier for beginners and can be carried away from sources of electricity. Its disadvantages: the need to constantly fill the cylinders; a large area of ‚Äč‚Äčthermal exposure (due to what the surface is subjected to deformations); Nothing should be flammable around the place of work in order to avoid a fire. Acetylene is more expensive than electricity and therefore the workers will get more expensive.

Working principle

Electric welding is called because the heat source in this process is an electric arc. It occurs between two electrodes, one of which is the welding machine's electrode and the second is the surface of the sheets being processed. Due to the thermal exposure, the sheets are partially melted, the so-called is formed. Weld pool (cavity filled with liquid metal). From the effects of atmospheric oxygen, the processing zone protects the inert gas layer - argon, which is supplied from the device outside a special gas nozzle.

In gas welding equipment, a gas burner is a source of heat energy. It is formed due to the ignition of acetylene when it is combined with atmospheric oxygen. As a result, the treated surface melts and a weld pool occurs.

equipment

Inverter welding machine. Contains a transformer that lowers the network voltage to the desired level and cancels out its differences. This is the most popular type of equipment because it is saved in terms of energy consumption and it provides a steady flow of current, thereby achieving the weld with good quality. There are several types. TIG technology includes TIG AC / DC (Variable Current Operation) and TIG-DC (with direct current).

The device is terminated with electrodes. For thin sheets (up to 3 mm), electrodes with a diameter of 0.5 to 2.5 mm are used when the current is from 10 to 90 amperes. With the thickness of the leaves of 3 mm, the diameter of the electrode 3-4 mm and the current 140 to 180 are possible. If these parameters are not observed, burns are inevitable.

A semi-automatic automatic consists of a power source, a cable feed mechanism, torches, control systems. Semi-automatic welding as well as TIG takes place in the medium of inert gases, which is served through a special nozzle. Changing the semi-automatic is easier than the inverter. Some models have the option of welding with an electrode. There are universal ones that are equal to success in a semi-automatic mode, manual, TIG.

Gas devices consist of an acetylene generator, a water seal (which is actually securing the explosion), cylinders (to store and transport gas), gears (to reduce the pressure in the cylinder to workers), hoses and the actual burner.

Surface preparation

Before starting welding, it is necessary to clean the surface of the blades from all superfluous: remove dirt, rust, paint, scale, soil, lubricant, corrosion coating of corrosion, etc. First of all, everything does not run electrical current. Second, gases can be released from some substances under the influence of high temperatures, resulting in liquid metal splash. Because of the same gases, the seam becomes porous; H. ugly and unreliable. Automatic preservatives include solvents that burn, highlight, poisonous vaporizers, etc.

You can look at dirt with a brushed metal bristle. It also makes sense to make and wrap the edges of the gas burner sheets. This is especially true if you are going to be cooking online.

Preliminary work

Before starting the TIG, it is desirable to lend the device on the pieces of metal, which is similar to the one that is used for scalding. So you can check whether the selected current is optimal. If the current is too large, a test piece will be melted. At a minimum, he wakes up, and a drop appears from within. If the electricity is insufficient, the province will not. In both cases, the current strength must be changed, reduced or increased. After you have reached the optimum, you can move on to work.

If it is assumed that the seam will be a mustache, then first of all it is necessary to connect sheets to each other in small seams, the so-called. Patches. The purpose of this procedure is to fix the fastening of sheets among themselves so that their mutual place does not change, and eliminates the gap. With a small length of the seam, the size of the tapes is no more than 0.5 cm, and the distance between adjacent ones is 5-10 cm. If the seam is planned long, then the size of the tape will be 2-3 cm, the interval is 30-50 centimeters. It is possible that the same purpose of fastening is used with self-adjustments, clamps, bolts, etc. This type of fixation must also be used if you are going to be cooking online. Otherwise, the space between the details will be formed and you risk even more.

Some experts believe that the mustache seams are better because they cannot boil gas, because for this it is necessary to heat the metal too high, which leads to greater deformation.

When welding electrodenship, tapes, you need short touch, 1-3 seconds, no longer. Hold the electrode off and quickly return until the surface cools. Otherwise the burner is exposed.

How to cook the electrode

The long seam needs to be done through pieces by moving the electrode on the cooling section: up, down, middle, again. The shorter the length of the "stitch", the less the deformation of the leaves.

When cooking, it makes sense to put an additional seal under the seam. Cooking with TIG technology sheets thinner 1 mm without such a seal can only be a good inverter, imported electrodes and in the presence of welding skills. If there is an opportunity to remove the substrate, it is better to use a narrow (up to 1.5 cm) strip of the same metal. Take it in the seam. For everyone, if it is still there, the void will be removed.

If there is no such option, then it is desirable to put a thick piece of copper. Copper dissipates heat and the likelihood of exposure will decrease.

At the end of the work, the substrate must be removed. If there was no copper laying, then it is possible to use steel in this capacity, and after welding, remove it, and then carefully take it with a corner facing machine after welding.

How to cook gas

The flame of the gas burner is divided into three areas: the kernel, the reduction zone and the torch. The kernel has clear boundaries, in the shape near the cylinder. The diameter is equal to the diameter of the burner mouthpiece and the length depends on the rate of the gas mixture. The core is the middle zone, the so-called. Replacement, high temperature zone. It is called reductive because it contains hydrogen and carbon oxide which help deoxidize the metal in the weld pool, i.e. H. Binds oxygen. Thanks to this, the seams are smooth, without pores and muggy. In the working process, it is important to make sure that the flames of the metal affect this area.

Gas welding is right and left. With the left muffin, the burner runs right to right, a twisted wire (if used) feeds in front of the flame, and the flame itself is in a cold area where processing has not yet been done. Sweet metal welding is usually left over. The mouthpiece must be sent in a smooth wavy line. With a thickness of sheets of less than 1 mm with the kneading edges, the additional wire is not required. The force of the flame should be installed at the rate of 100 to 130 cubic decimeters of acetylene per hour on a metal thickness of 1 mm.

Safety measures

Welding work includes a number of specific factors that are dangerous to health and lifespan.

  • 1. There is a likelihood of damage when working with electricity;
  • 2. When working with gas - the risk of explosion from the generators of acetylene and gas cylinders;
  • 3. Burns to the skin and eyeballs and metal splashes;
  • 4. Harmful discharge - gases, pairs;
  • 5. Risk of fire.

In this regard, the following security rules are provided:

  • 1. Grounding electrical equipment to ensure insulation;
  • 2. Regular overview of electrical devices for health and leakage;
  • 3. Check the tightness of gas cylinders, the health of the water seal and the gearbox;
  • 4. Use of personal protective equipment: helmet, glasses, gloves, protective flaps, respirators;
  • 5. No flammable objects or materials in the vicinity. What is impossible to remove should be insulated with non-flammable protective materials.

Welding a thin metal electrode allows you to collect light structures with a large force margin. You can also use this to restore cars and repair many other thin-walled products. However, this process is quite complicated, it is very difficult to qualitative quality in the absence of experience.

In this material we analyze all the nuances of welding work on a thin sheet, which there are problems and how to avoid them.

The main problems that arise in the process of welding with electrodes made of fine metal, similar to the usual marriage with poor quality connectors.

  • Billet Burning.
  • Adhesive electrode.
  • Deformation of the material.

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

The adhesion of the electrode occurs in two cases: with a small strength of the current and that close to the tip of the consumer on the metal surface. These two negative factors contribute to the formation of an uneven joint and consequently degrade the quality of the weld.

Nonwoven seam is a common mistake allowed by newbies to the welding business. FORMALING BRAKING metal, the tip of the electrode is removed at a great distance, and the melt is simply spread over the surface. As a result, during the stripping, it turns out that the seam is uneven and there are no connected sites.

Deformation is also a fairly common phenomenon when welding a thin metal. This is a result of the effects of high temperatures.

How is the welding of fine metal and what are the options for solving the problem of marriage?

Selection of modes and electrodes

It is best to use the inverter for welding thin-walled structures. Such devices have a thinner setting, unlike transformer analogs.

The force used in such works depends directly on the thickness of the parts and the diameter of the electrode.

Thin metal is considered a blank with a thickness of up to 5 millimeters. However, the problems with welding occur with the details up to 3mm. In the table you can see the approximate match of the selected power to the material and the diameter of the electrode.

This is approximate data, more accurate setting of the device can be determined by experimental means to boil the metal.

The thing to note with the subtle types of electrodes is that the melting speed is faster, which means the seam needs to be faster.

The main requirements for the choice of consumables are the same as those for welding standard structures. The coating and composition of the electrode must match the metal being welded.

Right technology

Technologically welding fine metal is almost no different from the process of joining thicker structures. All work can be divided into three stages:

  • Manufacture of parts.
  • Welding process.
  • Strip seams.

The main differences in some nuances that allow the qualifying sheet to be cooked and cooked galvanized.

preparation

All preparation begins with cleaning the surface of the material from contamination. It is important to carefully clean the place where the mass holder will be installed.

Galvanized sheet metal in the place of future welding can be cleaned from the protective layer with a grinder. However, you can cook and directly on it, the zinc layer will burn in the working process.

welding

The algorithm for welding in thin metal is next.

  • The electrode at the end, the coolant can be cleaned for a length of about 5mm, but contribute to the quick arsus of the arc.
  • You need to make point tips of material along the entire length of the future seam (to avoid further deformation). For this it makes short-term Brangenden and welding the edges of the metal in the form of a point or for a length of 10 mm.
  • The arc is simply detonated - they are made in two ways. Either tap the tip of the electrode for metal or chirkanim. The length of the arch is optimal within 2-3 millimeters. Typically, the distance between the electrode and the metal must be able to withstand the diameter of the consumption!
  • After that, form a bath of molten metal and start running seams. In the operating process, the weld pool must have an elongated oval shape. This indicates a qualitative seam.
  • In order to avoid the adhesion of the electrode, it is not worthwhile to "check" into the surface.

It is very convenient in this plan for beginners of welders to use an inverter with added antitrile features and ARC ingredients. If the electrode approaches the metal too closely, it resets the voltage. In this case there will be no closure and the electrode will not stick. With a large extension of the arc, the inverter generates additional voltage and the welding process is not interrupted.

  • Suture lead, with a holder with an electrode at an angle of 60 degrees. It is best to choose a position near a straight corner, but with the preservation of checking the weld pool and the seam itself. With too acute an angle, a convex joint will be obtained. This means the seam will show up and metal will not weld.
  • The electrode can be guided from left to right, or vertical connections are made from below. At the same time, during welding, you need to make transverse movements with zigzags (Christmas tree).
  • You also need to control the speed of movement. It has to be progressive and equal.

After the end of the work, you need to lift off the slag and check the connection for the presence of undoubtedly and burns on the metal surface.

Welding thin-walled structures

To avoid negative consequences when welding, some suitable techniques can be used.

Vangstest If the design allows, the sheets can be positioned on top of one another. In this case, the main thing does not burn the surface below.

Point connection. Technologically, such a seam is carried out in the form of place tapes. The bow is unwound, the metal is boiling and extinguishing in the right place. And furthermore, everything is repeated in the entire connection with one step in 3 diameter of the electrode.

By electrode. If there is a risk of burning a thin metal, you can clean an electrode from the coating and lay it along the future seam. When welding, you need to be good at convincing these places. In the same way, you can grow the burned holes.

You can also install reverse polarity for welding thin-walled structures. If the holder cable is inserted plus, and the ground is minus. Reverse polarity reduces the amount of heat at the tip of the electrode and helps prevent burns.

If you need to cook a massive part with a thin metal, the arch is set on fire on a thick-walled workpiece, wearing the weld to the joint in the process.

To remove excess heat from under the best of details, you can poke the copper strip. Copper is a very heat engine and avoids the burning and flowing of molten metal.

And what do you think of such kind of work as welding thin metal? If you have a lot of experience with welded joints from a fine material, share it in the comments on this article.