Welder: everything you need to know to buy the right one

For DIY lovers there is nothing like learning to weld, and for this they need a welder. That is why we are going to dedicate this article to teaching you everything you need to know about this subject, and some secrets that you may not have known, so that you can start creating projects joining different pieces of metal or plastic.

Let's enter the wonderful world of welding...

• The best welding machines you can buy

What is a welder?

Una welding machine It is a piece of equipment used to ensure the union of materials, achieving this link through the joint fusion of the materials or through the fusion of the material to be welded. For this, the welder provides an energy source capable of generating the necessary temperature for said union. These machines usually consist of several parts, depending on the type they are. Later we will study the types of welding machines and how they are in each of the cases...

Inverter vs conventional welder

Both a inverter welder like a traditional one they require transformers to bring the incoming current up to the level needed to melt the metal. However, inverter welding machines perform this task considerably more efficiently. An additional feature that makes them attractive is their compact size, their lightness and their lower energy consumption.

Due to their improved efficacy, they also present long work cycles. By incorporating advanced electronic components, these machines hardly lose heat compared to conventional ones. Therefore, inverter welders can use almost all of the input current, while old transformers could lose up to 20% efficiency due to thermal dissipation.

With higher output frequencies and monitoring software and current and voltage adjustment, the inverters generate a uniform, more detectable and manageable arc. In most cases, when operating on single-phase household power, inverter welders require a 15-amp outlet.

Additionally, with the inverter machines it is easier to adjust the current and voltage to adapt to different materials and thicknesses, giving the operator more precise control over the task. The compact dimension and low weight of inverter welders make them very popular among professionals, being especially suitable for manufacturing workshops and construction environments. This makes repairs on the jobsite much easier, making them much more manageable.

DC vs AC Welder

For differentiate between one type of welding and anotherWe have to take into account the following points:

• Alternating Current (AC): The quality of the weld generated by these machines does not reach optimal levels, not because of the welder, but because of the fluctuations in the current output. AC welding machines, as their name suggests, generate a current that alternates over time. This current is not constant, which implies that the heat distribution fluctuates throughout the process. In terms of soldering, this results in uneven joints. It is possible to achieve adequate weld points, but not continuous and uniform beads. The asymmetry is manifested in the cords due to the variation of current from positive to negative, impacting the electric arc. Inconsistent heat delivery and the lack of a consistent welding arc require more effort from the welder to get quality results.
  • Advantages:
    • They tend to be compact in size.
    • Arc blow problems can be easily fixed.
    • Best for aluminum welding.
    • Best for welding thick metals or where more penetration is needed.
  • Disadvantages:
    • They do not produce smooth welds.
    • The fluctuation makes the weld not so uniform.
    • Maximum splash.
    • It is more difficult to work.
• Direct Current (DC): they have a not too significant cost difference, investing in a quality equipment with direct current (DC) output implies additional benefits. Among the advantages of working with a DC welding machine, in addition to the stability of the weld, are the possibility of achieving continuous and uniform seams, reducing or eliminating welding defects. The greater control over the heat applied to the piece is notable, and can even be regulated, thanks to the greater constancy of the direct current. Another positive aspect of DC welding machines is their adaptability for specific welding processes, such as the TIG (Tungsten Inert Gas) or argon process, as well as other procedures that may not be feasible with AC machines.
  • Advantages:
    • Greater stability.
    • Smoother welds.
    • Few splashes.
    • Best for thin metals.
    • It is easier to operate.
  • Disadvantages:
    • The equipment is a little more expensive.
    • Not an option for aluminum.

types of welding

Between the types of welding we have to differentiate between:

MMA (Manual Metal Arc) or arc (STICK)

This form of welding had its beginnings in the 1930s and has continued to evolve to this day. It has maintained its popularity due to its simplicity and ease of learning, as well as its low operating cost. However, it does not produce perfect welds, as it tends to generate spatter. Often a post-cleaning process is required.

In this process, a replaceable electrode is used which also acts as input material. An electric arc is generated from the end of the electrode to the base metals, melting the electrode and creating the filler material that forms the joint. The electrode is coated with flux which, when heated, creates a cloud of gas that protects the molten metal from oxidation. As it cools, this gas solidifies and forms a layer of slag.

Because does not require additional gases, this method is suitable for use outdoors, even under adverse weather conditions such as rain and wind. It also works effectively on surfaces with rust, paint, or dirt, making it ideal for equipment repairs.

Various types of electrodes are available and are easily interchangeable, allowing adapt to different types of metals. However, this process is not optimal for thin metal work and requires a long learning curve to master.

MIG (Metal Inert Gas)

La MIG welding it's a simple process that is accessible even to novice welders. It involves a quick procedure in which filler metal is supplied through a wire while gas is released around it to preserve it from external influences. For this reason, its applicability outdoors is limited. However, this process is highly versatile and can be used to join various types of metal with different thicknesses.

The filler material consists of a consumable wire which is fed from a reel and, at the same time, acts as an electrode. When an arc is generated from the tip of the wire to the base metal, this wire melts, becoming filler material and giving rise to the welded joint.

Wire is fed continuously through the gun, allowing you to control the speed at which you work. When executed correctly, MIG welding produces smooth and resistant joints, with a visually pleasing appearance.

MAG (Metal Active Gas)

It is very similar to the previous one. The MAG welding represents a method of joining by electric arc in which a consumable electrode is used and a protective gas is introduced that plays a fundamental role in the welding process. This gas not only fulfills a protective function, but also actively intervenes by amalgamating with the carbon present in the molten metal.

In the context of MAG welding, active gases are used, including options such as pure carbon dioxide (CO2) or a combination of gases such as argon, CO2 and oxygen (O2). That is, you will need to connect a gas bottle or cylinder to the welder for it to work, which is better for workshops than for taking from one place to another...

TIG (Tungsten Inert Gas)

La TIG welding, also known as Heliarc, is an arc welding technique that involves tungsten and gas. In this method, the electrode is made of tungsten and is not consumed during the process. It is one of the few types of welding in which it is not necessary to use a filler metal, since the two metals being welded can be directly fused.

If you choose to use a filler metal, it must be added manually. To carry out TIG welding, it is essential to have a constant supply of gas from a dedicated tank, ensuring adequate protection of the weld. Therefore, it is advisable to carry it out indoors, where interference from external elements is avoided.

TIG welding stands out for its precision and aesthetics of the welded joints, since it does not generate splashes. Due to these characteristics, it is a complex welding technique that is recommended for experienced welders.

TO BE

This welding method is Applicable to both metals and thermoplastics. As its name suggests, it involves the use of a laser as a heat source to carry out the welded joints. It can be used on a variety of materials, including carbon steel, stainless steel, HSLA steels, titanium, and aluminum.

It has many advantages over previous welders, with high precision and quality joints, and even allowing welding in very diverse environments. However, it must be said that the laser welding machines are quite expensive. They are generally only used in industry, such as the automobile industry, where robots weld parts of the chassis or bodywork using this method...

by electron beam

This form of welding involves the use of a high speed electron beam to generate heat through its kinetic energy, melting and uniting two materials. This welding process is highly advanced in nature and is carried out through automated equipment, normally under vacuum conditions. Usually, these types of welding machines are only used in industry, for specific applications, and they are also expensive and advanced like lasers.

Plasma

welding by plasma arc uses a smaller arc, which increases the precision of the joining process. In addition, it uses a different torch that manages to reach even higher temperatures.

Inside the torch generates a gas under pressure, generating a plasma state. This plasma ionizes, making it a conductor of electricity. This makes arcing possible, generating exceptionally high temperatures that can melt base metals. This feature allows plasma arc welding to be performed without the need for filler metal, in a similarity to TIG welding.

This welding technique allows to achieve a deep penetration with narrow beads, resulting in aesthetically attractive joints with a high degree of resistance. In addition to these advantages, considerably high welding speeds can also be achieved.

by atomic hydrogen

La atomic hydrogen welding represents an extremely high heat joining method, formerly referred to as arc atom welding. This technique involves the use of hydrogen gas as a protective agent between two electrodes made of tungsten. This welding is capable of generating temperatures higher than those generated by an acetylene torch, and can be carried out both with and without the introduction of filler metal. This welding approach, although previous, has been replaced in recent years by the MIG welding method.

electroslag

This advanced welding technique It is used to vertically join the thin edge of two sheets of metal. Instead of applying the weld to the outer surface of a joint, it is made between the very edges of both sheets.

Un copper electrode wire it is fed through a consumable metal conductor tube that assumes the function of filler material. By applying electricity, the arc is struck and the weld begins from the bottom of the joint, gradually moving up and generating the joint as it goes. This procedure is fully automated and carried out using specialized machines.

SAW (Submerged Arc Welding)

All the SAW welding machines, also known as submerged arc systems, are a type of electric welding equipment that uses a fusion electrode and uses granular flux as a shielding agent, with the electric arc hidden under a layer of flux. First, the granular flux is evenly distributed over the solder joint of the part to be joined. The electrode tip and work piece are then connected to two phases of the welding power source to generate the electric arc. Finally, the welding wire is automatically fed and the electric arc is moved to carry out the welding. These submerged arc systems are suitable for joining a variety of materials such as carbon structural steel, low alloy structural steel, stainless steel, heat resistant steel, nickel based alloys, and copper alloys.

high frequency

the machines of high frequency welding They present distinctive characteristics compared to other welding equipment, since they offer functionalities beyond the simple joining of materials. These welding devices stand out for their ability to heat quickly and their high efficiency, being capable of instantly melting any metal object.

In addition to their ability to join various metallic materials by welding, high frequency welding machines are versatile in other applications such as diathermy, casting and heat treatment, as well as for joining other types of materials. Additionally, due to their compact design, their low weight of just a few kilograms, they do not require acetylene or oxygen cylinders, making them a highly portable and effective option in challenging environments or outdoors.

How to choose the right welder

The first thing is to determine what kind of materials you need to join and how much budget you have. Only with these two factors will you be able to rule out a multitude of machines and go for a more defined group of welders. However, this is not the only thing, choosing the right welder can be an important decision, since it influences the quality of your welding projects. Here are some key factors to consider when selecting a welder:

• Weld Type: Determine what type of welding you need to do. The main types include MIG, TIG, MAG, SAW,… Each type has its own applications and requirements, as I have explained above. It is important to note that currently you can find many equipment that supports multiple methods welding machines, such as MMA+MIG+TIG machines, which can weld with these three methods, without the need to have three different pieces of equipment.
• Portability and size: If you need to move the welder frequently, consider its weight and size. The more portable machines are often useful for jobs in different locations. At present there are very compact equipment, and even gun-shaped welders.
• Amperage: Proper amperage varies based on type of metal, thickness of material, type of electrode or welding wire, and other factors. Using the correct amperage is essential to achieving safe, consistent, and properly fused welds. Too much amperage can result in excessive heat, spatter, and a weak or distorted weld, while too little amperage can lead to poor joints and lack of fusion. On the market there are welding machines with maximum amperages such as 120A, 300A, etc.
• Power source: Welders can run on single or three phase electricity. Make sure the power source is available at your location.
• Work cycle: we refer to the period during which a welder can operate at its maximum sustained capacity. This period encompasses 10 minutes in which the arc welder can operate at its full rated power. For example, a 60% duty cycle at 300 amps means the welder can be used for 6 minutes (at 300 amps), after which active cooling must be allowed for 4 minutes with fan operation. This approach has the obvious purpose of minimizing the risk of damage caused by accumulated heat in the system.
• Quality and brand: Research reliable makes and models that offer a good reputation in terms of quality and durability. Some examples of recommended brands are Cevik, Miller, Metalworks, Greencut, Lincoln Electric, JBC, Telwin, Esab, Weller, Krafter, PTK, Daewo, Soltec, Vevor, Hitbox, etc.
• Accessories and additional features: some welders come with additional features such as cooling systems, wire feed speed adjustments, voltage regulation, etc. Determine which features are important to your needs. In addition, there are kits where they also bring gloves, a mask, etc.

Necessary accessories for welding

In addition to choosing a good welder, it is also important to equip yourself with the suitable accessories to work safely and avoid accidents. To do this, you have to get hold of:

• Gloves: it is vital to get good gloves to avoid burns when touching the parts of the metal close to the welding zone. These gloves are robust and are usually made of leather.
• Mask: of course, if you don't want to burn your cornea from welding flashes, you have to wear a welder's mask. Keep in mind that without it you could have very painful eye injuries and even lose your vision. Within the masks we can distinguish between:
  • Normal: it's a conventional mask, with opaque glass that filters harmful light, although it can be tricky for beginners, since you can't see where you position the electrode. Within this type we can find:
    • Manual: It is a mask in the form of a screen that covers the entire head, with a window where the glass that filters the light is located. It is held with one hand, the one you have free and you are not using with the electrode. The negative is that you will have to keep one hand busy with the mask, the positive is that you can easily remove it if you want to see something.
    • helmet type: similar to the previous one, but you don't need to hold it by hand, it is put on the head with an adjustable headband and it has a hinge to raise or lower the mask. This leaves your hands free, but it can be slower if you want to remove it at a specific time to watch something.
  • Automatic: They are helmet type, but instead of having a normal opaque glass, they have an electronic screen that lets you see through it. They can work with the light itself through a photoelectric cell or need a battery in some cases. The nice thing is that the screen will remain transparent at first, letting you see where you position the electrode, and it will automatically darken when the sparks start. In addition, some tend to have several modes, for cutting, welding, etc., and even allow regulating the delay and the intensity with which the screen darkens.
• Appropriate clothing and footwear: the ideal is to use work overalls that cover all the skin of the extremities and trunk, since sparks can fly that could cause burns when coming into contact with the skin. Of course, the footwear is also important, since it must have an insulating sole to avoid possible discharges.
• Mask: You may also need a mask to avoid inhaling toxic gases when welding galvanized metal, since the surface of these metals, when heated, gives off toxic fumes. It is also important to use it for some tungsten electrodes, such as those that carry thorium, since they can be harmful to health.

Don't forget to read our article about The best welding machines you can buy...