MIG Vs TIG! Whats the difference? Which one should you use? Whats the pros and cons of each?
MIG and TIG welding are two types of welding that use an electric arc and a shielding gas.
However, they differ in the type of welding electrodes used to create the arc.
MIG welding uses a machine-fed solid wire, while TIG welding uses a non-consumable electrode and a hand-held filler rod.
As a result of these differences, each welding process has advantages, disadvantages, and preferred applications.
To explore this further, let’s look closely at each method.
In The Blue Corner – MIG
Metal inert gas (MIG) welding, formally known as gas metal arc welding (GMAW), employs an automated or semi-automated arc to accomplish the welding process.
When MIG welding, a wire electrode is used as the filler material, which is consumed during the process. Additionally, a shielding gas is utilised to protect the weld, enhance weld penetration, and reduce the occurrence of weld bead porosity.
The welding gun, which supplies the electrode and shielding gas, plays a crucial role. Typically, a shielding gas blend comprising 75% argon and 25% CO2 is utilised. However, other mixtures may be employed based on the materials and specific factors.
A continuous, consumable wire electrode and a shielding gas are directed through a lead to the welding gun. The size and material of the wire used for welding can differ based on the type of metals being joined, the thickness of the pieces, and the type of connection needed.
The wire feed speed (WFS) settings determine how fast the electrode is fed into the weld, ensuring an adequate supply of weld metal for the joint.
In The Red Corner – TIG
Gas tungsten arc welding (GTAW), also known as Tungsten inert gas (TIG) welding, is a welding process that uses an arc, similar to MIG welding.
It involves a tungsten electrode (that is not consumed)and a separate filler material fed manually into the weld pool using both hands.
The filler rod’s composition and size depend on the weld type being conducted.
TIG welding employs 100% argon as a shielding gas. CO2 can cause tungsten oxide formation that can contaminate the weld and wear out the electrode prematurely.
In addition, TIG welding uses a foot pedal that enables the welder to control the amperage, allowing precise control over the heat introduced to the metal during welding.
Advantages and Disadvantages
Comparing the advantages and disadvantages of MIG and TIG welding provides valuable insights into these two popular welding processes.
Knowing the strengths and weaknesses of different welding methods can help welders and fabricators choose the best one for their project, resulting in optimal efficiency and results.
MIG Advantages and Disadvantages
MIG welding is frequently the preferred method when joining large and thick materials.
This technique uses a consumable wire as both the electrode and filler material.
MIG welding is faster than TIG welding, meaning production times are shorter and costs are lower.
Additionally, MIG welding is easier to learn and can create welds that require minimal cleaning and finishing.
It is worth mentioning that MIG welds may not possess the same precision, strength, or visual appeal as those created by an expert TIG welder.
TIG Advantages and Disadvantages
The TIG welding method uses a non-consumable tungsten electrode in combination with a separate filler rod to join small and thin materials.
This method is adaptable and suitable for various types of materials.
Due to the higher temperatures of the torch, TIG requires less amperage. However, it is slower compared to MIG welding, which can result in longer production times and increased costs.
TIG welding is more challenging to learn and requires skilled practitioners to produce accurate and precise welds. The larger and bulkier torch also makes it more difficult to see the welding puddle.
Despite these challenges, TIG welding provides greater control over the welding process, resulting in more robust, precise, and aesthetically pleasing welds than MIG welding.
Applications
MIG Applications
MIG welding is an excellent option for those who want to learn to weld.
It is easy to understand, simple to use, and can join various materials, including aluminium, mild steel, and stainless steel.
It is a great choice for thicker metals and where the appearance of the weld is not a major concern.
TIG Applications
TIG welding is challenging to master but produces more accurate outcomes than MIG welding.
It is ideal for welding thinner materials, including aluminium, copper, steel, and titanium.
TIG welding finds extensive application in jobs that demand precision, such as aerospace, motorsport, industrial structures, production line manufacture, and many more.
The Key Differences
We previously discussed the disparities between MIG and TIG welding techniques.
MIG is considered more convenient to master and execute, quicker, and ideal for welding thicker materials.
On the other hand, TIG welding provides better control and accuracy, is suited for thinner materials, and produces tidier welds with minimal finishing required.
Besides these broad distinctions, several differences can be classified based on properties, cost, and ease of learning.
Weld Strength
When it comes to welding, TIG welded joins tend to be stronger than those produced by MIG welding.
This is because TIG welders create a narrow, focused arc for better metal penetration.
If applied correctly, TIG weld beads contain very few holes or defects that can weaken the weld.
However, it’s important to note that MIG welds can still be strong if certain precautions are taken.
For example, grinding or cutting a V-shaped groove into the joint before welding can increase penetration.
Good travel speed and torch positioning can also improve the strength of MIG welds.
Weld Speed
MIG welders are known for their faster welding speeds in a production setting.
This is because they automatically feed filler material into the weld pool, and their rounder and broader arc dissipate heat better.
This allows welders to move the welding material quicker and complete longer runs without the risk of overheating.
On the other hand, TIG welders can only move the weld puddle slowly, and they need more filler rods to compete with MIG welding speeds.
Additionally, the air-cooled torches used in TIG welding get too hot during lengthy welding runs, so they need to cool down or be replaced with more expensive water-cooled torches.
Shielding Gas
Shielding gas is used to ensure high-quality welds in both MIG and TIG welding.
This gas acts as a protective layer for the weld puddle, guarding it against reactive gases in the air that could lead to impurities.
For TIG welding, pure argon gas is usually employed to shield the weld, as the tungsten electrode is susceptible to reactive gases such as oxygen or CO2.
On the other hand, MIG welding typically employs a blend of 75% argon and 25% CO2, as the addition of carbon dioxide helps stabilise the arc and improve penetration.
However, there may be exceptions to these general shielding gas rules, depending on the specific application.
For instance, TIG welding may sometimes blend argon with helium, hydrogen, or nitrogen.
When welding aluminium, MIG welding uses 100% pure argon or pure CO2 to save costs and enhance weld penetration.
Additionally, the two methods have different shielding gas flow rates.
MIG welding usually requires 35 to 50 cubic feet per hour, while TIG welding uses 15 to 25 cubic feet per hour.
Weld Aesthetics
TIG welding typically results in better-looking welds than MIG welding.
TIG welds produce minimal or no spatter and usually only require light polishing to remove discolouration.
Welded stacks of “coins” created through TIG welding are considered the most visually appealing and can enhance the look of unpainted welds in materials like steel or aluminium.
On the other hand, MIG welds have a less attractive appearance, even though skilled welders can still produce aesthetically pleasing MIG weld beads.
Nevertheless, MIG welding is suitable for applications where appearance is not a major concern or if the welds will be coated, concealing the joint’s appearance.
Process Difficulty
MIG is generally considered easier to learn and master compared to TIG.
To perform TIG welding, you need to use both hands. One hand is used to move the welding torch, while the other hand is used to feed the filler rod.
Additionally, a foot pedal is often used to control the amperage, making the process more challenging to master.
TIG welding also requires thorough cleaning and preparation of the metals to be joined.
On the other hand, MIG welding is simpler as it does not involve a foot pedal, and the welding gun automatically feeds the filler material.
This means that only one hand is needed to complete the weld.
Cost
TIG welding is more expensive per foot of bead due to lower deposition rates and the need for skilled and costly welders.
Additionally, TIG welding involves more preparation work, which increases the cost.
Furthermore, the supplies and machines for MIG welding are typically less expensive than those for TIG welding.
These factors all contribute to the higher cost of TIG welding.
FAQs
Is TIG Better Than MIG?
Deciding whether TIG or MIG is superior depends on several factors.
TIG can provide stronger welds and a better appearance when executed correctly by a skilled welder.
However, if the welder lacks experience, MIG welding may produce a higher-quality weld.
Additionally, MIG welding is quicker than TIG welding, making it possible to complete longer runs in a shorter time.
In conclusion, the choice between TIG and MIG depends on the specific circumstances.
Should I Learn MIG Or TIG welding?
The choice between learning MIG or TIG welding depends on your goals.
- If you prioritise ease of learning and productivity, go for MIG welding.
- If precision and high-quality welds are important, choose TIG welding.
If you are a complete beginner, it’s best to start learning the basics of welding with MIG or Stick. MIG is easier to handle and allows for producing acceptable welds more quickly and efficiently.
Is TIG welding harder than MIG?
TIG welding is generally considered to be more difficult than MIG welding due to the need for precise manual control, coordination of multiple actions, and the use of a non-consumable electrode.
How To Choose The Correct Process
It can be difficult to determine whether to use MIG or TIG welding because of the variances between the two methods.
However, both methods have their unique benefits that can serve as a helpful guide in choosing the appropriate technique.
When to use MIG:
- Thicker materials – MIG welding is more appropriate for joining thicker stock materials.
- Long runs – MIG welding’s continuous wire feed is advantageous for longer runs as it requires fewer stops and starts to replace filler material compared to TIG welding. This results in a reduced risk of weld defects.
- Difficult positions – Using MIG is simple, even in challenging positions, because it only needs one hand to operate.
- High productivity – When it comes to productivity, MIG welding is more efficient than TIG welding because TIG welding takes longer to complete.
- Less experienced welders – MIG welding is more beginner-friendly than TIG welding, making it a better option for welders with less experience.
When to use TIG:
- Thinner materials – TIG welding is perfect for bonding thin materials prone to burn through or warping due to its precision and accuracy.
- Short runs – TIG welding is most suitable for small-scale production.
- Shop or bench work – Managing TIG out of position can be challenging, so it is best to perform this process in a bench or shop setting for optimal results.
- Delicate or fine work – TIG welding is ideal for a visually pleasing final weld. TIG welding is recommended for visible pieces like automotive restoration or artwork. This process enables better control to prevent burning or warping.
- Non-ferrous metals – Professional welders typically use TIG welding for working with materials such as aluminium, copper, stainless steel, and other speciality metals.
- Experienced welders – A skilled welder is a must to fully benefit from TIG welding. Otherwise, it’s best to consider a simpler method like MIG welding.
How Does The Amperage Of MIG And TIG Compare?
The amperage required for MIG welding and TIG welding can vary depending on the specific job requirements, such as the type and thickness of the metal being welded. However, here’s a general comparison:
MIG Welding:
- MIG welding typically uses higher amperage compared to TIG welding.
- The amperage range for MIG welding can vary from around 30 amps for thin materials up to several hundred amps for thicker materials.
- The higher amperage in MIG welding is needed to melt the wire electrode quickly and provide sufficient heat for deep penetration and effective fusion.
TIG Welding:
- TIG welding generally uses lower amperage compared to MIG welding.
- The amperage range for TIG welding can start as low as five amps for thin materials and can go up to a few hundred amps for thicker materials.
- TIG welding requires lower amperage because it relies on precise control of the heat input to create a focused and concentrated arc. It allows for better control over the weld pool and reduces the risk of overheating or distorting the base metal.
It’s important to note that the specific amperage settings for welding jobs should be determined based on factors such as the type and thickness of the metal, joint design, welding position, and desired weld quality. The welding machine and electrode size also play a role in determining the appropriate amperage settings. Welding parameters should be selected based on industry standards, manufacturer recommendations, and the expertise of the welder.
How Do The Welding Puddle And Arc Visibility Differ Between MIG And TIG?
The visibility of the welding puddle and arc differs between MIG (Metal Inert Gas) welding and TIG (Tungsten Inert Gas) welding due to the differences in the welding processes. Here’s how they compare:
MIG Welding:
- Visibility of the Welding Puddle: In MIG welding, the welding puddle is typically less visible due to the wire electrode’s continuous feed and the shielding gas’s presence. The wire electrode is consumed and continuously fed through the welding gun, creating a small welding puddle. The shielding gas around the arc protects the molten metal from atmospheric contamination. As a result, the welding puddle is somewhat obscured by the continuous flow of the wire and the shielding gas.
- Visibility of the Arc: The arc in MIG welding is generally less visible compared to TIG welding. The shielding gas used in MIG welding helps to stabilise the arc, but it also tends to dim the brightness of the arc. The bright arc is typically concentrated at the tip of the welding gun, where the wire electrode makes contact with the base metal.
TIG Welding:
- Visibility of the Welding Puddle: In TIG welding, the welding puddle is more visible compared to MIG welding. Since TIG welding involves manually adding a filler rod to the weld puddle, the welder has a clear view of the molten metal. This visibility allows the welder to closely monitor and control the weld puddle’s size, shape, and penetration.
- Visibility of the Arc: The arc in TIG welding is generally more visible and brighter compared to MIG welding. TIG welding utilises a non-consumable tungsten electrode, which produces a focused and intense arc. During welding, the tungsten electrode remains intact, which provides a clear view of the arc and its interaction with the base metal. The bright and visible arc enables the welder to control the welding process precisely.
In summary, MIG welding tends to have a less visible welding puddle and a slightly dimmed arc due to the continuous wire feed and shielding gas. On the other hand, TIG welding offers better visibility of the welding puddle and a brighter, more visible arc, which allows for greater control and precision during the welding process.
Can You Slow MIG Down Enough That It Is Similar To TIG And You Can Do Very Precise Welds?
While MIG (Metal Inert Gas) welding is generally known for its higher welding speeds and productivity than TIG (Tungsten Inert Gas) welding, it can slow down the MIG process and achieve more precise welds. Here are a few factors to consider:
Welding Technique
By adjusting your welding technique, you can have better control over the MIG process. This includes reducing the travel speed, using shorter arc lengths, and manipulating the welding gun more precisely. Slowing the movement and maintaining a steady hand can help achieve more precise welds.
Wire Size and Type
The wire size and type used in MIG welding can influence the precision of the welds. When using a wire with a smaller diameter, the control over heat input and filler metal deposition becomes more precise. Additionally, selecting a wire with a lower deposition rate can help achieve more precise welds.
Shielding Gas
The choice of shielding gas can also impact weld quality and precision. Some shielding gas mixtures, such as argon-rich blends, provide better control over the arc and produce cleaner welds. Consult with welding experts or refer to manufacturer recommendations to select the appropriate shielding gas for your specific welding application.
Welding Parameters
Adjusting the welding parameters, such as voltage, amperage, and wire feed speed, can help fine-tune the MIG welding process for more precise welds. Lowering the voltage and wire feed speed can reduce heat input and allow for better control over the weld puddle. Experimenting with different parameters and practising on scrap materials can help you find the optimal settings for your desired precision.
While these techniques can help slow down the MIG welding process and improve precision, it’s important to note that TIG welding still offers finer control and is generally better suited for highly precise welds. TIG welding is the preferred option for applications that demand the utmost precision and weld quality due to its manual control over the filler rod and accurate heat input.
Conclusion
When it comes to welding, there are two main methods: MIG and TIG. MIG welding involves using a hand-held torch to feed a continuously-fed electrode wire and shielding gas. On the other hand, TIG welding uses a tungsten electrode and a separate filler rod.
Shielding gas is fed through a supply line, and a torch-mounted control or foot pedal is used to adjust the amperage.
It’s important to note that neither method is better than the other. Each has its advantages and disadvantages, depending on the situation.
MIG welding is often preferred for its low cost, fast welds, and ease of use. This makes it a good choice for less experienced welders who still need to produce high-quality results.
TIG welding, on the other hand, is more difficult to master and can be more expensive and slower. However, it can deliver unparalleled accuracy and aesthetic quality that MIG welding can’t match.
TIG welding is ideal for thinner or more delicate jobs, while MIG welding is better suited for thicker materials.
