When I was a beginner, I felt it difficult to judge whether to use TIG or MIG Welding. Therefore, today I decided to extract my knowledge and experience for your ease. Here is the detailed comparison, thorough insight & applications regarding the major welding types.
List of Contents
- An Overview of the Welding Techniques
- Nature of the arc
- Electrodes used in the Process
- Filler Wire
- MIG vs TIG vs Stick Welding
- Welding Process Selection according to Base Metal
An Overview of the Welding Techniques
Gas tungsten arc welding or TIG welding produces very high-quality weld, and it involves using a non-consumable tungsten electrode, which provides the arc. But not filler metal and runs a current through the metal to be joined as electrode heats the metal and liquify. The filler is added manually or can be supplied as a separate rod or wire into the weld puddle, and two pieces are welded.
Inert gas flows through the electrode holder to shield the electrode, arc, and pool of molten metal. In the adjacent heat areas also CO2 is not added in this process because it provides inadequate protection for the tungsten electrode). Argon is the most widely used gas as it produces a smoother and stable arc; helium can be added to increase heat input (higher welding speeds and deeper penetration).
Metal inert gas welding (MIG) or Gas metal arc welding (GMAW) is an arc process in which joining is done by producing heat or arc through the short circuit in the consumable electrode. The electrode can be a continuous, solid, or hollow tube with powdered alloy additions in the center called a metal-cored electrode.
Along the arc is an inert gas that melts the metal and allows them to join together. Once the heat is removed, the metal begins to cool and solidify, forming a new piece of fused metal.
Now, I will discuss how MIG and TIG processes differ in various welding terms one by one.
Nature of the arc
For TIG, it is important to control arc length throughout the process. If a hot tungsten electrode meets the workpiece or molten pool, it can contaminate the electrode. Most common engineering metals and alloys can be welded through this process. The use of inert gas makes it suitable for reactive metals such as aluminum, magnesium, titanium, high-temperature superalloys, and refractory metals.
Electrodes used in the Process
In TIG, the composition, diameter, length, and tip geometry of Tungsten and its alloy electrode selected based on the material being welded, the thickness of the material, and the type of current used. For better current-carrying and electron emission characteristics, Tungsten is often alloyed with 1 to 4 % thorium oxide, zirconium oxide to increase the life span of the electrode. During the welding, the arc remains constant, stable, and easy to maintain.
As you know now, TIG welding involves a non-consumable electrode, so we have to add a filler material by some other means. While in this case, you have to feed the molten puddle employing your hand. To achieve cleanness and superior weld, you must be very focused and have a fine grip over your hands.
MIG vs TIG vs Stick Welding
In MIG, TIG, or stick welding techniques, the way of arc use is different. In MIG welding, feed wire continually moves through the gun to create a spark and melts to form the weld by short-circuit and inert gas shield.
While in TIG, welding long rods are used to fuse two metals, and filler material is separated from the rod, sometimes filler material is not required, and in TIG, spatter doesn’t produce. TIG cannot be used for aluminum welding because of Ac & DC limitations.
In stick welding, the electrode is usually flux-coated metal. During the process, both the electrode and the metal workpiece melt, forming a weld pool. The molten metal then cools to create a sturdy joint between the two metals. But all these welding techniques heat the metal until it reaches a liquid state, and filler material is used to join the metals, and both require clean surfaces to get the best results.
Advantages & Disadvantages of Stick Welding:
- Stick welding doesn’t require gas tanks or any special knowledge about welding gases.
- It can be used for iron, steel, aluminum, nickel, and copper alloys.
- It can create effective bonds on rusty or unclean surfaces.
- Poor Quality Weld.
- Spatter and porosity are hard to avoid.
- Requires Polishing
- Time Intensive
Welding Process Selection according to Base Metal
In the next part, I’ll guide you on selecting the right welding process for commonly used base metals.
It depends on the requirement. Stainless steel can be welded with shielded metal arc welding (MIG), gas tungsten arc welding (TIG), and stick welding, and each of the processes yields a slightly different result.
If artistry is paramount, the finesse of TIG welding could be a good fit, but if speed and efficiency are a priority, then your choice should be MIG.
Steel Alloys or Aluminum:
TIG welding is known for its precision, so for work that demands cleanliness, controlled welds, especially on less-forgiving materials like stainless steel alloys or Aluminum. Although it produces beautiful welds, it is also the slowest welding process, requiring an experienced welder with excellent technique. Distortion to control is easiest in TIG.
The most common welding techniques for automotive parts are Gas, Stick, MIG, and TIG. Among these four, Mig is the winner. You can almost use it for every application in cars and other automotive parts. But as mentioned above, it is inadequate for precision, so you have to be focused on the torch. With this, you can try many little experiments of yours in your garage.
Gas welding is the oldest form of welding. Having an Oxy-Acetylene set up in your home garage allows you to heat stubborn bolts and pre-heat parts. Having a rosebud tip allows cutting through thick metal. However, gas welding is hard to learn and challenging to weld thin metal.
Stick or Arc welding is easy to learn and doesn’t require a gas tank but does require a lot of clean-up. It is excellent for all kinds of projects but not the right choice for thin sheet metal.
Which technique to choose between Tig vs. Mig Welding?
It entirely depends on the type of materials and how fast you want your job done. For Aluminum and steel, Mig welding would be preferable, and it is also a low cost. While Tig can also be for Stainless steel & Aluminum, the weld quality would be charming, but it will take a longer time, and it is costly too.
Can we use TIG Welding for automotive parts?
Tig welding has less penetration, but it is highly recommended to work on an expensive car project or motorcycle frame. The welds are of superior quality & offer high strength.
Why is Welding Stainless steel so difficult?
During welding, Stainless steel can store heat and acts as a reservoir, so during welding, the temperature rises between the torch and the workpiece exponentially. So when the piece is cooled, its shape becomes distorted, and its aesthetics are no longer alluring.
Now you know all the merits & demerits of both TIG vs. MIG welding. MIG is faster, cheaper, and more comfortable than TIG welding, and it is used for automotive welding. But if you want something that can withstand standards, then you know the second option.
Many beginners try to master first in MIG welding, which is a great idea, and when their passion excels, they practice TIG Welding. Safety is also essential to see our best welding helmet 2021.
TIG welding is the primary method used in the aerospace industry. TIG is more costly, time-consuming, and difficult while it produces high-quality welds, which are cleaner and more precise welds than MIG or other arc welding techniques, making it more efficient and higher in quality.