MIG Welding Machines

Which MIG welder should I buy?

When purchasing, it is vital to seek professional advice, and this is exactly what we offer at AES. The MIG welding process has advanced significantly in recent years, and there are many welding jobs, especially on stainless steel and aluminium, where optimum welding results could only be achieved by TIG welding, but now can be achieved with the latest technology in MIG welding machines with synergic control and digital technology.

The first consideration is, does it have sufficient duty cycle at the amperage that I require. For example, I may be wanting to weld 3 - 5mm thick material on a continual basis, so could be looking for a machine with say 150 - 200 amps capacity. As soon as I start to search the internet for a 200 MIG welding machine, it will be full of companies selling these types of machines. However, as soon as we start to look into the duty cycle of some of these machines, we see a different story.

What is MIG welding?

MIG (Metal Inert Gas) welding is one of the easiest and simplest forms of welding as well as the most common method used when melting and joining metal with a MIG welding torch. It’s a semi-automatic welding process as the length of the arc and the wire feed is controlled automatically but the speed of travel and position of the torch is controlled manually. MIG welding is a convenient method as it can weld a variety of metals including nickel, copper, aluminium, stainless steel, carbon steel and more. Unalloyed, low-alloy, and high-alloy steels are often welded. MIG welding is popular with both professional welders and hobbyists.

A MIG welding torch feeds welding wire, usually from a reel inside a welding machine, to the metal that is being welded. The MIG torch uses electricity and gas to create a short circuit that melts the filler metal to form a weld pool. When the weld pool and two base metals cool, they will be formed and hardened together.

What is MAG welding?

MAG (Metal Active Gas) welding is a series of arc welding techniques that fuse the metal in the joint region using the heat generated by an electric arc. Powered wheels feed a continuous electrode into the weld pool.

What is the difference between MIG and MAG welding?

The difference between MIG and MAG is simply the gas that’s used. MIG welding (Metal Inert Gas) uses inert gas as the shielding gas, the shielding gas is generally argon, however, helium is also applied. MAG welding (Metal Active Gas) uses active gas shielding which is a combination of carbon dioxide (CO2), argon and oxygen.

The shielding gas is contained in a high-pressure porcelain cylinder which is then extracted through a regulator which decreases the pressure, through the gas diffuser to the end of the gun.

Choosing the correct type and amount of shielding gas is important as it effects the strength of the weld, quantity of welding spatter produced, the level of penetration and the weld pool. The purpose of the shielding gas is to protect the weld of contamination from other gases including hydrogen, nitrogen, and oxygen, of which can cause welding spatter and porosity.

MAG welding is a faster process than MIG welding, therefore is suited to extended welds. MAG also does not produce slag, prevents oxygen entering the weld and the welds are thicker, deeper, and stronger than MIG welding. However, when welding thinner metals, MIG is the preferred method as it provides a superior finish.

Similarities between MIG and MAG welding?

MIG and MAG welding are both arc and fusion welding techniques which indicates an electric arc is constituted between the electrode and workpiece and this arc is the prime source of heat required to fuse the surfaces of base metals. Both are also GMAW (Gas Metal Arc Welding) techniques. GMAW is a type of arc welding technique in which a consumable electrode is constantly supplied to the welding zone to supply filler metal, as previously indicated. The two types of GMAW processes are Metal Inert Gas (MIG) and Metal Active Gas (MAG).

In both situations, shielding gas is required (and hence consumed); but the nature of the shielding gas differs. The composition of the shielding gas is the most important element in determining whether a GMAW process is MIG or MAG.

To supply sufficient filler metal, both use a consumable electrode that is continually supplied to the welding zone. None of them can be utilised for autogenous mode welding since filler is naturally applied and for homogeneous mode welding, MIG and MAG are commonly employed.

In both situations, spatter is present. Both methods achieve roughly the same penetration depth.

MIG welding advantages

  • MIG can weld various types of metal and different thicknesses
  • Quicker to learn than other welding methods due to automated processes which would otherwise be difficult
  • High productivity due to efficiency of long weld passes which is suitable for larger metals being welded
  • Speedier due to continuously fed wire
  • Ability to weld on flat surfaces/horizontal or even vertically
  • Clean high-quality welds mean minimal post-weld tidying due to no slag, no flux and very little spatter
  • High deposition rate
  • Simple arc ignition

MIG welding disadvantages

  • The welder may have less control compared to TIG
  • Cost due to maintenance and spares
  • Portability, although some less powerful welders are compact
  • Not suitable for thicker welds and very thin welds
  • The shielding gas requires protection from external elements such as wind and rain (unless gas shielded/welding tents are used)
  • Costs to start compared to TIG (although some machines can weld multiple methods)
  • MIG torches are larger than TIG, making it harder to reach tight spaces
  • Susceptible to rust, porosity, spatter and poor fusion

Reasons why MIG welding is better than TIG?

  • Quicker
  • Easier
  • Better at welding thicker metals
  • More productive
  • Slimmer chance of errors
  • Performs stronger welds

TIG welding advantages

For advanced welders, TIG can provide higher levels of control and accuracy, the ability to weld in almost any position and its better at welding thinner metals. Plus, it can be more portable due to less equipment, supplies and weight.

What is MIG welding used for?

For larger and thicker materials, MIG welding is commonly utilised. It makes use of a disposable wire that serves as both an electrode and a filler material.

It's significantly quicker than TIG welding, resulting in shorter lead times and reduced manufacturing costs. It's also simpler to learn and generates welds that don't need much cleaning or polishing. Its welds, on the other hand, are not as accurate, robust, or clean as those produced by TIG welding.

What is MAG welding used for?

A consumable wire electrode is used to produce an electric arc between a consumable wire electrode and the material being connected in MAG welding. Active shielding gases are used in MAG welding, which is typically used for steel welding. Carbon dioxide, argon, and oxygen are used as shielding gases.

What is difference between MIG and TIG welding?

An electric arc is used in both MIG and TIG welding to generate the weld. The way the arc is employed is the distinction between the two. MIG welding creates a spark by moving a feed wire through the gun, which then melts to produce the weld. TIG welding fuses two metals together directly using long rods.

Why is MIG welding so popular?

The MIG welding method outperforms earlier welding procedures in terms of speed, which is one of the reasons it has become the most prevalent type of welding. The widespread availability of semi-inert gases like carbon dioxide, which were formerly difficult to get by, has made their application in steel products considerably more popular.

What is better MIG or TIG welding?

MIG welding is a quicker form of welding that is excellent for tasks that require a greater rate of output. The size of your project may influence the type of welding you use because TIG welders create accurate and clean welds making them ideal for thinner metals and smaller tasks.

MIG welding melting point

At approximately 1600 degrees Celsius, the base metal melts and forms with the filler metal.

MIG welding current

Direct current

The welding current in MIG is direct current (DC), the wire is positive, and the base metal is negative. Direct current power sources are the most popular and have a high level of stability because they are based on the notion that an electric arc will automatically stabilise if it’s powered at a consistent voltage and created on a wire fed at a constant pace. The choice of voltage and wire feed rate parameters is rather flexible due to the process' flexibility. Using either the "short arc" immersion method or the "spray arc" approach, drop transfer from the welding material to the material to be welded can be achieved in this manner.

Pulsed current

In this scenario, the power source regulates the current rather than the voltage, which is not maintained constant but varied by a series of impulses. The objective of the impulses is to drive the drop to separate from the welding material; in this situation, the arc is not naturally stabilised, therefore the impulses and wire feed rate must be properly synchronised to create a satisfactory weld.

Both the first and second cases require at least two knobs for regulation; however, current industrial research has led to the creation and sale of "synergetic" type welding equipment that require just one control knob from the operator. Depending on the task requirements, the manufacturer memorises the ideal welding settings in the power source, which may be remembered and/or modified by the operator.

Direct current with straight polarity connection

The torch is linked to the negative pole of the power source, while the material to be welded is attached to the positive pole; this form of connection is only utilised when welding tubular wire.

Direct current with reverse polarity connection

When welding in this mode, the torch is connected to the positive pole of the power source, while the piece to be welded is connected to the negative pole; this is the most common type of connection.

How does a MIG welding machine work?

The machine contains a spool holder which is where a reel of welding wire is seated securely, there should be some friction when the spool turns. In front of the spool holder and reel of wire are rollers, the rollers pull the wire through the feeder and welding lead to a welding torch that is connected to the machine, the wire feeds through the tip of the torch ready to be welded.

The speed at which the wire is pulled through the welder is controlled by a trigger on the torch. To begin welding, the torch requires a copper tip, metal shroud and earth clamp. The copper tip guides the wire out of the torch, the shroud protects the wire and guides the gas whereas the earth clamp either connects to the metal being welded or the welding turntable.

Personal Protective Equipment (PPE) and Respiratory Protective Equipment (RPE)

Every part of the person welding must be protected by welding PPE/RPE to prevent injury and long-term health defects, for example, welding overalls. Welders are protected by the health and safety government act, HSE, which regulates the industry and businesses. We have a complete range of safety equipment including PPE and RPE to protect yourself, employees and others round you while welding to comply with regulations.

Ensure the surrounding area is clear of any flammable materials as spatter and grinding sparks can easily land on flammable materials and cause a fire, welding screens or curtains can help with this. In case of a fire, store a CO2 fire extinguisher nearby.

Which gases are used in MIG welding?

Argon, or CO2 and argon is used when MIG welding as these shielding gases facilitate a clean and high-quality weld with minimal spatter and avoids discolouring.

What MIG wire & shielding gas do I need?

Metal Electrode Shielding Gas
Carbon Steel ER70S-3
100% CO2
75-90% Argon + 10-25% CO2
82-98% Argon + 2-18% CO2
95-98% Argon + 2-5% Oxygen
90% Argon + 7.5% CO2 + 2.5% Oxygen
Low Alloy Steel ER80S-Ni1
100% CO2
75-80% Argon + 20-25% CO2
95% Argon + 5% CO2
95-98% Argon + 2-5% Oxygen
Aluminium ER1100
ER4043, ER4047
ER5183, ER5356
ER5554, ER5556
100% Argon
75% Helium + 25% Argon
75% Argon + 25% Helium
100% Helium
Austenitic Stainless Steel ER308LSi
98-99% Argon + 1-2% Oxygen
90% Helium + 7.5% Argon + 2.5% CO2
55% Helium + 42.5% Argon + 2.5 CO2
98-99% Argon + 1-2% Oxygen
98% Argon + 2% CO2
97-99% Argon + 1-3% Hydrogen
55% Helium + 42.5% Argon + 2.5% CO2
Nickel Alloys ERNiCr-3

90% Helium + 7.5% Argon + 2.5% CO2
89% Argon + 10.5% Helium + .5% CO2
66.1% Argon + 33% Helium + .9% CO2
75% Argon + 25% Helium
75% Helium + 25% Argon
100% Argon
89% Argon + 10.5% helium + .5% CO2
66.1% Argon + 33% Helium + .9% CO2
75% Helium + 25% Argon
75% Argon + 25% Helium
97-99% Argon + 1-3% Hydrogen
Copper Alloys ERCu (Deoxidized) 100% Argon
75% Argon + 25% Helium
75% Helium + 25% Argon

Argon Gas

Argon (Ar) is an inert gas that is created by fractional distilling of the atmosphere. Because the gas is collected from the air, it may include traces of contaminants like oxygen, nitrogen, or water vapour, but it’s still acceptable for most welding applications. In MAG applications, this gas provides high arc stability and a simple striking. Furthermore, due to its low thermal conductivity, the core section of the arc column maintains a high temperature, allowing the drops to pass through the arc zone.

Helium Gas

Helium (He) is an inert, somewhat rare gas that is taken from the ground rather than the atmosphere, making it much more expensive than argon. Helium has a less steady arc than argon but higher penetration; it's typically used for thick welds and materials with high heat conductivity, including copper and aluminium. Because helium is lighter than air and hence more volatile than argon, a larger amount of gas is required to create an adequate shield for the welding zone.

Carbon Dioxide

CO2 is an active gas that may be found in the atmosphere and underground. The most common issue with this sort of shield is that it can generate excessive spray and create an unstable arc; however, if the arc is maintained short and steady in length, it is feasible to keep it under control. When using a CO2 shield, better penetration is usually achieved.

Gasless MIG welding

Gasless MIG wire is not at all gasless, it’s not possible to MIG weld without gas (unless you are in a non-oxidised atmosphere). The more accurate term is self-shielding MIG wire as it’s just that. The gas is required to shield and protect the weld pool from oxygen in the air. Self-shielding or gasless MIG wire burns the flux core which creates the shielding gas around the weld pool.

The advantage of gasless MIG wire is that MIG welding is possible in windy conditions if you don’t have a gas cylinder or a welding tent. The drawbacks are that its ineffective on very thin metals and it produces significant quantities of fumes. Before using gasless MIG wire, make sure your welder is compatible, look for the “No Gas” marking on your machine or manual.

Cleaning MIG welding equipment and supplies

Before starting to weld, make sure all the equipment and parts are both clean and in good working condition, as you’ll soon notice during or after the weld if it isn’t. This means all torch consumables such as the nozzles, gas shroud, contact tip, swan neck, insulator, steel liner diffuser etc. Also, the welding cables, earth clamp, the parts including the feed rollers and the spool holder, ensure the wire is not rusty, and the welding area in general. When you are done welding, remove the wire from the spool in the machine to prevent rust.

What type of wire liner do I need?

They’re made in three materials which are plastic, Teflon, and steel. The steel liners are most common as they’re strong and used for welding mild steel. For welding aluminium, Teflon is best, however, plastic liners can also be used.

How do you know you are welding correctly?

If the metal you are welding looks like it’s produced short bursts or a thin bead of molten metal, the power you are welding at is too low. If the metal you’re welding has melted a hole straight through the other side or there’re deep holes in the metal, the power is too high. Also make sure to set the correct amperage for the wire you are using.

You carry the risk of heat distortion if the metal you’re welding is thin, meaning the metal could become unshapen. To avoid heat distortion, try staggering by welding sections for a limited time and moving around the metal, effectively spreading out the heat. At the start of a weld, its best to tack weld or clamp the metal you’re welding to a bench or turntable if you can.

When the settings are correct, the weld will look smooth, consistent and the colours will match, the sound of the sparks produced should be continuous. If the sound is inconsistent but the settings are correct, the wire that protrudes from the tip is likely too long. Generally, the length of the protruding wire should be around 3/8 inch. You shouldn’t have any small balls of metal or air bubbles (porosity) on the weld, if this happens, you may need more gas pressure. To avoid a "weld crater," the arc must be adjusted. This is accomplished by welding until the desired weld length is reached, then reversing the direction of travel for about an inch before releasing the torch trigger.

Ensure to hold the MIG gun the same distance away from the metal throughout the weld, the distance should be between a quarter, to half an inch for a consistent weld. You could find out if you’ve been welding too close if the wire becomes attached to the tip of the gun and won’t come out. However, this is a simple fix, just use a pair of pliers to remove the wire, and you might need a new tip.

Post weld, if the metals have failed to join or the join is weak, this could be due to too little speed of wire and power. Always make sure the metal you’re welding is clean and free of rust, dirt, and paint, grinding the metal you intend to weld prior to welding is good practice. Expect quality issues when MIG welding dirty or rusty metals.

Another impact of performance is the machine itself. They need to be tested via a welding machine calibration at least every 12 months by a qualified professional to ensure the voltage, amperage, and wire feed speed and possibly the gas flow rate is still working as it should. If you are struggling to decide how much gas flow rate to use, the below table is a good starting point.

Air cooled vs water cooled

Air cooled torches are heavier as they consume much more copper to cool the nozzle with shielding gas. Although, they are less expensive to buy, requires less hoses and doesn’t need a cooling system. They are the simpler machine to put together, to use and maintain.

A water-cooling system in the form of a radiator cools the air and shielding gas, these guns are lighter and more flexible to use than air cooled, and the consumables are more durable. However, they are more expensive and difficult to maintain.

How to set MIG Gas Flow Rate

Shroud Diameter (mm) 10 11 12 13 14 15 16 17 18 19 20
Flow Rate (litres per minute) 6 7 9 10 12 14 16 18 20 22 24

Just because you have the best welder and torch on the market, doesn’t mean the equipment doesn’t need looking after. Always ensure that the equipment including its internal and external parts are in good condition and clear from debris which means you shouldn’t only check every 12 months. Always check the equipment’s specifications before purchase and use to ensure all the parts can work together and weld safely and appropriately. For example, check the duty cycle and power capacity to ensure limits are not exceeded.

We recommend learning MIG welding best practices. There is plenty of information available to research, professional advice to follow, try speaking to experts regarding unique or specific challenges of a project, especially if you’re unsure. It’s always best to read the machine and torch owner’s manual and go back to it when appropriate to ensure you are following the procedures correctly and getting the most from your equipment.

There are many features on MIG welders, what do they mean?

Arc force/Choke

This simply controls the penetration of the weld. Higher penetration is for welding thicker metal and lower penetration is for welding thinner metals.

Push Pull torch

When welding aluminium, the head of the MIG torch has a pair of rollers as well to support the feed of the wire and avoid common issues such as snags.

Soft Start

This feature is what it says on the tin, soft start slowly begins the weld upon pulling the trigger. The advantage of this feature is that it provides a controlled start and prevents torch jerk reaction when the wire makes contact, the welder will then instantly increase the wire speed, continuing the weld.

Four roll wire feed

Two rollers both at the top and bottom of the welding machine ensures a more secure and precise wire feed and feed speed facilitating a higher quality weld. The quality of the motor wire feed and the drive plate such as its material impacts not only the durability of these parts but also the quality of the weld.

Benefits of Euro style torches over fixed torch

  • It’s simple to fit Euro style and replacement parts, with fixed torches it can be much trickier
  • Speed of the wire feed is more consistent which protects the condition of the weld
  • Euro sockets simply screw onto the welder with a hand nut
  • In most cases, Euro style is the superior option

Replacing MIG torch liners

From time to time, a torch will need a new torch liner, they are flimsy and very small in diameter. Due to this, they must be replaced if they become bent, clogged, or worn out after prolonged use. If you notice a change or difference when the torch is feeding the wire such as inconsistencies, check the torch liner for damage.

What does duty cycle mean in welding?

Duty cycle simply tells you how long a welder will operate before it begins to overheat. Duty cycle is made up of the number of amps, percentage of the work period before overheating and the temperature the machine was welded at. In the UK, the work period is 10 minutes. However, manufacturers often won’t include the temperature on their machines.

Health and safety

Safety first is extremely important when welding, make sure you have quality MIG gloves for the job, made of protective materials such as leather and cowhide. Welders prefer gloves that fit around the hand rather than covering for flexible working as well as gloves that aren’t too thick, so they don’t impede the welder, and replace when worn. Although remember the higher the amps of the torch, the thicker the gloves should be. Unsure what size glove to buy? Use the chart below.

What size welding glove do I need?

6"-7" 7"-8" 8"-9" 9"-10" 10"-11" 11"-12"

The most important piece of safety equipment is a welding helmet, preferably an air fed welding helmet that is auto darkening. An auto darkening welding helmet protects the eyes from injury including arc eye, never weld without a welding helmet. Air fed masks protect the welder from breathing in harmful fumes and gases proven to cause cancer.

Welding clothing that is of natural material and heat resistant/leather including overalls, aprons, shorts, trousers to protect from grinding sparks and spatter. Leather or steel toecap boots are best as to protect from falling objects and molten metal.

We’ve covered protection from welding fumes and gases with air fed helmets. However, its best practice to double up in cases of prolonged welding and heavy fabrication applications through local exhaust ventilation (LEV). LEV includes on-torch extraction which are specially made MIG torches built to extract fumes at source through the nozzle of the torch. Portable, mobile and wall mounted fume extractors have arms which extract fumes through the nozzle and up through the pipe. The extraction arms are pointed directly towards the welding application to catch the fumes as they form.

Common MIG welding wire

Forehand (push) vs Backhand (pull) Method

The forehand push is the most common method which creates a shallow weld that is flat and wide pushing the arc away from the weld pool. The backhand pull creates a slimmer but deeper weld.

MIG welding cast iron

Brazing cast iron with MIG is possible. MIG welding cast iron is not recommended as it won’t be as strong as other processes such as MMA or TIG, weld using a different process if you can.

MIG welding aluminium

Welding aluminium is trickier than other metals due to some of its prominent characteristics. Aluminium warms very quickly and spreads meaning its more susceptible to overheating which leads to damage, distortion, bending, splitting and can even melt a hole through the other side. To stop heat damage, tack weld, or clamp down the aluminium during the weld. Try placing a back plate behind the metal to avert welding a hole through thin aluminium.

Weld as quickly and efficiently as you can, in a single pass, if possible, to prevent porosity in the weld. A single pass is also helpful in preventing cold lapping by keeping the aluminium at the correct temperature throughout. The metal must be well cleaned since aluminium’s reaction to oxygen causes resistance to corrosion, if oil is present, clean with degreaser. Its best to use a stainless-steel wire brush reserved for cleaning aluminium, do not vigorously scrub the metal, brush in one direction.

Make sure the tips are manufactured for welding aluminium and that Teflon liner and u-groove rollers are fitted to the machine or use an aluminium spool. In some instances, a push-pull gun can be used for precise wire feeding. Generally, argon is used to weld aluminium with a gas flow rate of 14 to 16 litres per minute, and of course don’t overheat the MIG gun by exceeding the power capacity. The best wire to use is 5356, 4043 can also do the job.

MIG welding stainless steel

Use Teflon wire for a smooth feed and to avoid any possibility of the weld becoming damaged, as stainless steel although resistant to corrosion, is prone to contaminants. Welding stainless steel produces higher heat than average, so make sure the MIG torch amp capacity won’t be exceeded.

Ensure the metal is entirely clean before welding, and you’re using the appropriate wire for the application. Only use stainless steel brushes and grinding and cutting discs to clean. Like welding aluminium, the rule of thumb is a gas flow rate of 14 to 16 litres per minute, tack weld and clamp the metal to avoid damage during the weld and stagger as to not overheat.

How to set the MIG wire feed speed

Set a speed you think will be more than required before doing a test weld, if there is a quick back and forth motion on the weld, lack of penetration or welding spatter appears, incrementally decrease the wire feed speed. Once the weld feels smooth, the feed speed is correct for the selected power output.

What wire feed speed do I need?

Another way to set wire feed speed at the starting point is to follow the table below. These figures are estimated and likely to require tuning.

Steel Thickness (mm) Wire Speed (metres per minute)
0.6mm Wire 0.8mm Wire
0.8 2.5 1.6
1.0 3.0 1.9
1.2 3.6 2.2
1.5 4.3 2.6
2.0 5.6 3.5
3.0 7.9 4.9
4.0 9.8 6.1
5.0 12.5 7.7

MIG welder wire feed roller tension

Wire feed roller tension is a setting on a MIG welding machine that adjusts the rollers grip on welding wire, the rollers then feed the wire through the torch. The roller is too loose if it slips or feeds too quickly which can ultimately burn the torch tip. The first three inches of wire should be straight to help prevent damage to the liner or catching of the wire as it’s fed through. Releasing the wire can cause it to unravel and tangle. If the roller is too tight, the welding wire and torch liner could be damaged and cause the tension mountings to bend as the wire feed motor becomes strained, some MIG wires such as aluminium can even become flattened.

Feeding the wire to the torch

First, the wire needs to be fed through the guide tube, then over the wire feed roller. The wire can then be inserted into the liner, approximately three inches. Turn on the welder, feed the wire through using the wire feed. Dependent on the welder, you could remove the contact tip from the torch before the wire is fed.

MIG welding angles and positions

For regular welding positions, the MIG torch should be held 5-15 degrees from the metal being welded. Any higher such as 20-25 degrees could cause a weaker join, a reduction in arc penetration and spatter on the weld for a messy finish. The work angle is the position of the torch in comparison to the metal being welded.

Flat position

The simplest type of welding is flat welding. Typically, the MIG gun is pushed, and the angle of the MIG gun can range from straight down to up to 35 degrees leaning toward the weld direction. Use a high voltage setting, any pattern will work if the weld penetrates, but a steady motion works best. If you're new to this, turn the machine up to its maximum setting. This is good practice since it ensures that the weld penetrates.

Horizontal position

Horizontal welding is more difficult. The MIG gun should be tilted 15 to 35 degrees toward the weld direction and pointed upward between 35 and 45 degrees. Keep an eye out for overlapping welds and the weld sliding over. On any joint, maintain it for tight stringer beads, whipping and circles work well in this situation. You can't compensate for a lack of competence by increasing the machine setting, with expertise and technique, the weld must be stretched out and controlled.

Vertical down position

It's simple to go vertically down. Starting at the top and working your way down is the best way, the MIG gun must be angled between 35 and 45 degrees. Welding vertically down has a knack to it; you must maintain the electrode moving from side to side to remain ahead of the water. The weld will not penetrate adequately if this is not done, if you remain ahead of the puddle, patterns won't matter.

Vertical up position

The most challenging MIG welding position is vertical up, the MIG gun handle should be angled upwards at a 35–45-degree angle. When welding vertically up, you'll need to create a weld shelf to work on. In MIG, the vertical up weld is generally convex, if you need assistance welding vertically, it's usually a good idea to grind a small groove in the area where you'll be welding. This is one of the places where you can't seem to get the weld to look perfect no matter what you do. You can achieve a good quality weld if it’s wide enough, but else it looks like a highly convex weld.

Overhead position

The MIG gun must be angled 5 to 35 degrees toward the weld direction while doing overhead MIG welding. You need the heat to be on the higher side, and after a while, it'll be as simple as flat. There will most certainly be at least some spatter dropping, so you'll need to direct those sparks away from you.

Flat welding position general rule of thumb

Weld Position Joint Angle
Butt Weld 180-degree 90 degrees
T-joint 90 degree 45 degree
Lap joint or L-joint 90 degree 60-70 degree

MIG welding patterns

Steady motion pattern

A constant motion is the most fundamental method, and it necessitates that the welder be precisely adjusted. It’s the welding method used by most robots, and it can make a flawless weld in any position. Machine parameters, electrode angle, and travel speed all have a role. The principles of a steady motion are that the hotter the setting, the better the weld in most situations. There isn't much to this approach other than making sure everything is in order, this is how most out-of-position aluminium MIG welding is done.

Whipping pattern

Using stringer beads or fillet welds, whipping works effectively on most joints. It not only keeps the puddle contained, but it also preheats the joint before filling it with metal. Beginner welders can use this technique to learn how to control their travel speed.

Circle pattern

They’re effective on a wide range of joints and may be used on most welds, it works by welding in small circles.

Weaving pattern

Weaves are utilised for larger welds and can range from a tight side to side motion and can be used as a stringer bead to welds that are broad and large enough to weld in a single pass. Weaves are ideal for large joints with little or no distortion. There is a formula that allows for a particular amount of heat at a specific travel speed without weaving key joints.

What are the benefits of high-speed pulse MIG?

  • Higher welding speed (on average 35%) compared to standard pulse
  • Higher deposition rate (Kg/h) of 15%
  • Reduced heat input (35% lower) and less distortion
  • Higher welding quality with superior mechanical and metallic properties
  • Deeper penetration and lower risk of lack of fusion
  • Lower production costs and depreciation

Higher welding speed

High dynamics applied to the pulsation of HSP arc gives an extremely focused arc that increases the fluidity and pression of transfer as well as the wetting properties of the joints. This allows the operator to proceed faster with the torch and a time saving of 35%.

High deposition rate

High dynamics applied to the pulse of HSP arc allows you to increase the wire’s speed while maintaining the same current value when welding in standard pulse. The increase of wire quantity in the pool increases consequently the weight of deposit in the unit of time (kg/h). Tests made highlight deposition rate (Kg(h) obtained in fillet welding 10mm thickness in spray arc, standard pulse and HSP at the same current value.

Spray Arc Standard Pulse High Speed Pulse (HSP)
Wire diameter 1mm Wire diameter 1mm Wire diameter 1mm
Wire weight 6,0625 g/m Wire weight 6,0625 g/m Wire weight 6,0625 g/m
Current 255A Current 255A Current 255A
Voltage 30V Voltage 30V Voltage 30.5V
Wire speed 12,4m/min Wire speed 13,1m/min Wire speed 15m/min
Joint thickness 10mm Joint thickness 10mm Joint thickness 10mm
Joint length 20cm Joint length 20cm Joint length 20cm
Welding time 37 seconds Welding time 37 seconds Welding time 24 seconds
Deposition rate 4,52Kg/h Deposition rate 4,77Kg/h Deposition rate 5,46Kg/h

Lower heat input and less distortion

In HSP heat input is lower (35%) than standard pulse, so it’s particularly suitable for high quality welding.

When welding in HSP, temperatures are lower, and the heat affected zone (HAZ) is smaller. This means that mechanical and metallic joints’ properties are considerably higher compared to standard pulse welding.

Superior mechanical properties

Tensile strengths values in the pure deposit and HAZ are much higher in standard pulse meaning that a higher heat input increased considerably tensile strengths. In HSP, hardness and tensile strengths are in line with the class of metal the base material belongs to, therefore the heat input is not influential in the welded material. HSP generates deeper penetration and lower risk of lack of fusion than standard pulse.

Example of lower production costs and depreciation with high pulse MIG

  • Time saved in 1 hour of welding (arc on) = 21 min
  • Time saved in 8 hours of welding = 2hr 48 min
  • Average hourly labour cost = £17.50
  • Average monthly labour cost (172 hours) = £3015
  • Monthly time savings = 60.2hr
  • Monthly cost savings = £1055
  • Yearly cost savings = £12660

The solution that allows higher productivity

The concentration and accuracy of the arc are the differences between normal MIG/MAG welding and power focus welding. The concentration on the power focus mode allows to focalize the high arc temperature precisely on the middle of the deposition, avoiding overheating on the weld edges.

Specifications of standard arc

In case of butt welds, if the plates caulker presents narrow angles, the standard arc has the tendency to get out from the caulker and to focus only on one of the two plate corners. In this situation, it is normally necessary to increase the caulker’s angle degree (during the preparation) with consequent need of more filling passes.

Power focus specifications

On butt welding applications, the power focus arc keeps on staying concentrated in the exact centre of the caulker, so that full penetration is granted. In this way, it’s possible to work on very narrow caulkers, which demands less mechanical preparation and of course fewer filling passes. Power focus provides a stable arc even with a very long stick out.

Penetration by power focus

The difference, as well as in the size of the penetration, is also in the extent of the HAZ. Its less because the execution speed with the power focus is higher. Penetration by power focus on a T joint (10 mm thickness), when welded on the two sides, it comes up to the intersect crossing.

The solution for root pass in MIG welding

Features of power root

  • Optimised root pass welding
  • Vertical down in sound weld quality
  • Better model ability
  • 'Cold' droplet transfer
  • Thin sheet welding

The power root concept

Power root is an optimized short arc welding process with a cold droplet transfer. It allows unique weld quality for root pass welding.

1: A smooth ball is formed on the tip of the wire (base current)

2: When the wire reaches shortcut, the current increases for a short cycle

3: Controlled reduction of the amperage to optimise the pinch - effect

4: 'Cold' droplet transfer

5: Re-ignition of the arc

Optimised weld results

Power root reduces the danger of root concavity

  • The weld puddle is oscillating
  • This provides a good root penetration
  • Convex (positive) root even in constrained weld positions

Main benefits

  • Wide weld gaps possible/safe on irregular preparation
  • Vertical down welding (PG)
  • Overhead welding (PE)
  • Root pass welding for pipes

Thin sheet

The low heat input allows weldments on thin sheet without time consuming changes of the welding wire diameter.

Gap bridging

The cold droplet transfer provides process stable welding even with wide gaps. The model ability is significantly improved. The weld puddle is smooth and combined with a high viscosity.

V-groove/pipe welds

The optimised short arc cycle guarantees a high arc pressure even in constrained positions. No matter whether vertical down or overhead welding is executed, the root pass quality will be assured. Root pass welding has up to 4 times higher welding speed compared to vertical up.

Arc welding types

Short arc welding

If you're dealing with extremely thin metal sheets, delicate projects, or soft metals, or if you're welding from a problematic position, short arc welding is the way to go. A small droplet, reduced spatter, and a smooth material deposit are all advantages of a short arc weld.

Long arc welding

For thick metal sheets and plates, a lengthy welding arc is employed. It uses a spatter-intensive method to create a coarse material deposit and forms a lengthy arc.

Spray arc welding

Expert MAG welders or automated equipment utilise spray arc welding. With the aid of an argon-based combination of gases, it’s used to join thicker sheets and plates.

Spray arc welding allows for a wider melting area on metal sheets as well as faster welding. It makes a fine droplet of material deposits with very little splatter.

Pulsed arc welding

For all sorts of sheet and plate thicknesses, pulsed arc welding is employed. To improve weld and arc protection, it employs shielding gases combined with pure argon.

During the welding process, a pulsed current is sent through the wire, which forms droplets. The pulses' speed can be changed to suit the needs of the project. The result is a consistent flow of tiny droplets with minimal spatter. It produces material deposits that are essentially short-circuit-free.

Dip transfer arc welding

Dip transfer arcs have a reduced power range, which means they're related with low voltage and wire speed. Welding may be done in almost any position using the dip transfer arc. There is very little spatter, and the arc may be easily adjusted. It's especially well-suited to welding light gauge sheets and root passes.

Intermediate arc welding

At irregular intervals, short circuits, and spray transfer’s alternate. As a result, greater spattering occurs, therefore this arc should be avoided as much as possible.

Rotating arc welding

Because of the big heat input, rotating arcs are exceptionally strong and well-suited to welding thick workpieces. When the droplet detaches from the wire electrode, it is deflected to the side and transported to the weld pool in a rotating motion. This method can only be utilised with automated systems, limiting the number of applications that may be used.

Combined arc welding

Pulsed arcs and dip transfer arcs are frequently used in combined arcs. The pulsed arc provides the required penetration and heat input, while the dip transfer arc improves the weld pool's controllability. This arc is frequently utilised for out-of-position welding.

Globular arc welding

The short circuit approach is like the globular transfer method. The electrode wire arcs and encounters the base substance. However, the heat input is higher, and the wire is heated for longer which causes a bigger weld puddle to form at the gun's tip and drops into the joint.

What does duty cycle mean?

With a quality welding machine manufactured to the latest European standards, duty cycles are usually measured out of 10 minutes. So if for example, a welder is 60% duty cycle at 200 amps, this means that at a given temperature, you could weld at 200 amps for 6 minutes, the machine would have to then cool down for the remaining 4 minutes of the 10 minute duty cycle before you can then weld again. MIG welding machines that are supplied from AES are usually fitted with thermal overload protection, so that if you exceed the duty cycle, the machine will cut out to prevent over heating, thus protecting the life of the welding machine long term.

What technology do I need in a MIG welder?

There is a now lot of choice of technology available to any company wanting to buy a MIG welding machine, and its very important that the correct technical advice is provided to anyone wanting to invest in the correct welder. For many years, the only technology available was the traditional step voltage with a standard rectifier transformer.

What is the difference between step voltage control and a synergic MIG welder?

With traditional step voltage control on a MIG welding machine, there would typically be twenty to thirty step voltage settings on the front of the welding machine, and the welding would then have to continually and manually adjust the wire feed speed until its correct for that set voltage output. The benefit of synergic control is that the voltage is infinitely variable, and not only that, but the machine automatically chooses the optimum wire feed speed for that particular voltage.

This optimum setting for every voltage and amperage is often referred to as the synergic curve. This makes setting up considerably more simple enabling optimum results much more quickly. However, having said this, many welders still prefer the traditional method of setting up a welding machine, adjusting the voltage and amperage independently, this is mainly because welders all like to weld differently, and many welders feel that synergic doesn't offer them enough control over their welding parameters on the machine to get the results they need.

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Company Registration: 07988136 Registered Office: Olympic House, Collett, Southmead Park, Didcot, Oxfordshire, United Kingdom, OX11 7WB


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