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Metal inert gas welding (MIG) and Tungsten inert gas welding (TIG) are two of the most commonly used types of welding.
They each have different scenarios where they are the best choice. In general, MIG welding will be more utilitarian than TIG and offers wider usability.
It is important to recognize the advantages and limitations of each welding process so you can decide the proper course of action. Even if you are hiring a fabrication job and not performing the work yourself, this knowledge can help you make better-informed decisions.
Here are the Pros and Cons of MIG and TIG welding.
MIG vs. TIG Welding
When you are welding base metals, the metal is heated by an electric arc until it reaches a liquid state. Additionally, a filler material is also introduced to help create a weld pool and to make it easier to join the two metals.
Additionally, both of these systems require an inert gas to protect the weld. The welding guns will have a small gas funnel that allows an inert shielding gas such as argon or helium to flow and surround the active arc, keeping harmful compounds such as nitrogen and oxygen away from your work. By keeping these highly reactive gasses away, the shielding gas prevents cracking and porosity when the weld cools.
Both MIG and TIG create a weld by super-heating the base metals with an electric arc. Filler metal is also heated in by this arc and is used to help fuse the two pieces of metal. With MIG, the filler wire is automatically fed into the joint. With TIG, the filler metal is a rod of consumable material that is manually fed into the weld bead with one hand while the other hand controls the welding.
Advantages of Of Mig Welding
Mig welding is also called gas metal arc welding or (GMAW). One of the big advantages of MIG welding is that it can be used for thicker metals. With a given power supply, it is easier to get a higher amperage and sufficient heat to weld thicker pieces of metal. It can be used on thin sheet metal pieces on up to thicker, structural I-beams.
When working with the thin material, faster wire speed and lower amperage are required. In many cases, it is best to use the TIG process for working on extremely thin metals.
MIG welding is also faster. The MIG wire acts both as the electrode and the filler wire. This allows the welder to create the weld puddle more quickly and to swiftly move along the joint until the weld is completed. This speed factor is a major deciding factor for manufacturing facilities with high production rates, making MIG the primary welding type used in commercial industries. Even small welding shops will rely heavily on MIG welding machines.
The filler material can also help join two slightly dissimilar materials together.
Different wire types are needed based on the type of base material. When welding aluminum, the filler wire is much more flexible and requires a spool gun to feed the wire.
Industrial Robotic Welders are often either Laser welders or MIG welders.
Mig welding is very easy to learn. Most home welding machines are MIG as novices can start creating welds with less than an hour of practice. The shorter learning curve makes it more cost-effective for new hires to master. Sometimes it’s almost like using a “hot glue gun.” I’ve mentioned it before, but MIG was the welder I learned on when I was a kid.
The trigger controlled wire feeding makes it exceptionally attractive. This gives the user a lot of control and lets you do the welding with one hand. By comparison, TIG requires you to use both hands and a foot.
There are also lower costs associated with MIG welding. The filler wire is very affordable, and the machines only break down rarely. When they do fail, it is normally a fairly affordable part. By comparison, TIG welders need their tungsten electrode replaced more frequently. If you are just welding mild steel, you can use a Carbon DIoxide or Carbon Dioxide/Argon mix, which is an extremely cheap gas source.
The MIG welders are also cheaper and can be readily purchased by consumers for a few hundred dollars.
Best Metals For MIG Welding
- Stainless Steel
Advantages of TIG Welding
TIG Welders create that beautiful “stacked dimes” welding pattern. TIG plays a vital role in working with certain welds and for creating high-quality bonds.
TIG Welding is also called Gas Tungsten Arc Welding (GTAW). The TIG Welding process is known for its high-quality welds. The weld is very attractive, and you will often see welders proudly share their completed welds. This beauty is only achieved after years of practice, but the look is distinctive and sought after.
We’re seeing more TIG being used wherever the weld is going to be seen by the end consumer.
The operator has a great deal of control over the entire welding process. There is a foot pedal that they use to activate and control the level of the electric arc being generated by the non-consumable tungsten electrode. The TIG gun (electrode) is held in one hand, and the consumable filler rod is held in the other. This creates a great deal of control throughout the entire welding process, offering greater precision.
This precision is much slower than MIG welding. It also requires a great deal more training in order to master it. In some cases, we see TIG being used inside CNC machines where every aspect of the arc can be carefully controlled. TIG can also be used for robotic welders and is often a cleaner process, requiring less daily maintenance on those tools.
TIG welders can handle a wider array of metals. It is popular for use on aluminum and other exotic alloys. It can also be used on stainless steel alloys and other aluminized metals. We don’t see it being used as much for < article link> exhaust work <>, except for high-end project cars where the welds need to serve as showpieces.
Gas Tungsten Arc Welding is also needed for working with extremely thin material. Tig welders offer a pulse welding feature that can make it possible to work on thin metal without burning through the metal. The foot pedal also allows the heat to be dialed down to prevent damage to fine metals.
With a MIG weld, there is a great deal of spatter. The workpiece often needs to be cleaned and sanded following the job, and most industrial uses require the weld to be painted to prevent rust. With TIG, there are a lot of controls to adjust the pulse control, the hertz or frequency of the pulse can also be adjusted. This added control can help reduce the spatter, and also reduce the amount of heat that the metal has to endure. This reduces the burn marks down the edges of the weld.
Alternating Current TIG welding is a cleaner process. As the current alternates back and forth, the electric current switches between cleaning the weld and performing the weld. Additionally, the operator has more control over how much filler material is used. This generates fewer fumes and allows for a cleaner process, even when welding upside down and out of position.
As alluded to, the TIG machine pulse can be adjusted to create a precise weld bead. Then, the foot pedal allows even more control of the amount of heat.
The goal here is to keep from damaging the surrounding metal. By protecting the surrounding metal from prolonged heat exposure, it allows the molecular structure to retain it’s integrity, creating not only a stronger bond but greater strength in the surrounding weld.
The TIG can cost a little more in gas used, the price of the consumable, and in paying for the man-hours to create the beautiful weld beads. Additionally, you will likely pay a TIG welder a higher hourly wage in order to access their superior skillset, further driving up costs of the finished work.
When strength and precision are required over speed, or when working with an exotic metal, the TIG is able to offer a better quality of the weld.
Welding Without Filler Material
When welding material has a lower amount of conductivity, it heats up more quickly when exposed to electricity. This means that some materials that are resistant to other types of welding processes can be more rapidly welded with TIG and will not require filler material. Material such as steel and aluminum, which is more ductile requires more electricity to heat the material and more filler material, making it well suited for the MIG welding process.
Best Types Of Metal For TIG
- Nickel alloy
- Stainless steel