MIG vs TIG Welding: Differences, Aluminum

Different projects require different tools and methods, and this includes any welding project you might have. Welding has different types, and it is important to choose the right one if you want to get the results you envision.

Among these types, MIG and TIG are the ones that people get confused with the most. Aside from the nearly identical names, anyone with an untrained eye will think that their process is also the same. In reality, there are notable differences between the two and this is what you must understand before choosing one over the other in your projects, such as those involving aluminum.

If you are confused about MIG vs. TIG welding, especially for aluminum, don’t worry because you are not alone. Clearing this confusion is our goal, so stick around if you want to know more about it.

Differences

Because both MIG and TIG involves the use of an electric arc to heat and melt the metals and fuse them together using filler material, many use them interchangeably. They believe that there are no noticeable differences between the two methods anyway, that is why they go for the one that is most convenient or economical for them.

Admittedly, it is easy to confuse them with each other. Aside from the method we mentioned above, they also both require the use of a bare electrode, as well as a shielding gas that prevents the metals from being contaminated or undergo oxidation. Also, both methods can only be used on metals that are conductive in nature.

But these are where their similarities end. The most noteworthy differences between MIG and TIG welding are in terms of the following:

Operation

The easiest way to differentiate the two is through their operation. When they both use a filler material, they vary in how it is done.

Using a consumable wire-fed electrode is what mainly differentiates the two techniques. With MIG, the wire electrode is directly fed into the spool gun, allowing one-handed operation.

On the other hand, TIG, also known as GTAW, requires a two-handed operation because the tungsten electrode used is non-consumable. In order to meld two metals together, there must be a filler applied. In this case, it is a separate TIG filler rod; one hand operates the torch with the electrode and the other hand holds the filler rod.

Note that it is also possible to fuse metals without any filler with TIG.

Difficulty

With the differences in operation or handling present, this resulted in a varying degree of difficulty. Since the filler material is directly fed into the spool gun, most people find it easier to do MIG . When used with a filler rod, TIG requires a two-handed operation where the torch is simultaneously used with the filler material, and this may be too complicated for beginners.

MIG is also called as welding’s “hot glue gun” and this means it is easier to learn than TIG; like a glue gun, you only need to press the trigger to start and stop.

Equipment

While both MIG and TIG require the use of a shielding gas source and power supply, they require different equipment. The former involves using a spool or welding gun and a feed wire unit, while TIG involves the use of a torch, non-consumable electrode, foot pedal connected to the electrical supply, and separate filler material in the form of a rod if needed.

Filler and Filler Replacement

Both methods typically make use of a filler, but these fillers and filler replacement vary. Fillers in TIG consist of a rod measuring 60-180mm with a diameter of 1 to 3 mm, while the filler in MIG is in the form of a lengthy wire that has a 0.5 to 2 mm diameter and is wound in a wire-pool. Because the filler rod in TIG is shorter compared to the longer wire used in MIG, it will require more frequent replacements.

Speed

Because of its uncomplicated operation, MIG has the advantage when speed is an important factor in your project. This is ideal if productivity matters more than quality. On the other hand, the slower TIG may be a better option if quality and attention to detail are important.

Thickness of Material

Aluminum and steel, both mild and stainless, are suitable for both MIG and TIG. Their difference lies in the thickness of the material. If you are fusing thicker ones, MIG is recommended because it can do so faster. On the other hand, TIG is more suitable for thinner materials.

Project Size and Type

In terms of the type and size of the project, TIG  is suitable for small-scale ones that involve thinner materials. But for larger projects, such as in the industrial setting, where it involves thicker materials, MIG is ideal.

Appearance

If the quality or appearance of the weld is crucial for you, TIG is the best choice. Its finish is a lot cleaner, offering a smooth finish that is free of defects while ensuring a reliable joint is made.

Cost

The overall cost is higher with TIG, not just because of the materials and equipment required but also because it is more time-consuming. In contrast, MIG has cheaper and easily replaceable parts and is more cost-effective because you finish projects much faster.

Application

MIG is considered as more diverse because it can easily be used in different applications. On the other hand, TIG can also be done on a wide variety of projects, but its overall costs make it impractical to do so. That is why it is typically only used in artwork, automotive, ornamental design, and stainless steel applications.

Knowing these marked differences will allow you to easily choose which one is more appropriate for your project.

Which Type is Best?

Now that you are aware of their major differences, you may be wondering which type is considered as the best between MIG and TIG. By now, you know that there is no straight answer for that.

MIG is your best option if:

  • You require high strength bonds that require only minimal cleaning and sanding
  • Speed and accuracy are essential
  • It will be done indoors, as the shielding gases used are not ideal for outdoor use
  • You require only minimal fumes, especially for continuous operations
  • The metals are thick, but it can also be used on thinner metals. When working on thin metals, care is crucial to avoid burning through it
  • Your project involves heavy-duty work and longer operations, allowing you to work on more pieces in a short time
  • Minimal defects are important, as its continuous operation lessens starts and stops
  • One-handed operation is a must

On the other hand, go for TIG if:

  • You need beads that are aesthetically-pleasing and offer a beautiful finish
  • Attention to detail is required
  • You require your work to be spatter-free, resulting in a cleaner finish
  • The work area is extremely clean
  • You will only work on a small project
  • Environmental hazards are a concern, as TIG is considered more eco-friendly because of the minimal fumes and sparks it generates
  • It does not involve cast iron
  • You need more control
  • Spatter-free work is your goal
  • Stronger joints are needed
  • Less maintenance is needed, as TIG does not require sanding and cleaning in-between jobs

For general use, MIG is recommended because of its easy operation and versatility. TIG is more appropriate for the more experienced craftsmen and those that require neater results.

MIG vs TIG welding: Aluminum

If you are working on aluminum, you need to know which method is best for it. If it is your first attempt to weld aluminum, you may think that any type will work; in reality, this is not the case. Unlike other steel alloys, aluminum is harder to work with due to its high conductivity and low melting point. The oxide film present on the aluminum surface, as well as its alloys, has a higher melting point than aluminum itself and makes it tricky to work with even for experienced pros.

Not only that, there are also certain types of aluminum alloys that require specific filler materials before they can be properly welded. Also, the processes done pre-weld and post-weld vary because of the oxide film present.

All these factors make it impossible to use a single type for aluminum and all its alloys. That is why like other metals, the best welder for aluminum will depend on its purpose.

In most cases, TIG is used when aluminum is involved. This is primarily due to the fact that a person has more control with this method, which is crucial to prevent the aluminum from overheating. Since a filler rod is used, you can easily use a filler that has similar properties with the aluminum alloys you are working on. This allows a cleaner result on the aluminum and prevents feedability issues that sometimes occur with wire feeding.

TIG welders suitable for aluminum typically have the following characteristics:

  • AC-Powered – it is more suitable when dealing with the oxide film on the aluminum surface
  • Output Power (in Amperes) – the ideal range is 5 to 230 amperes
  • Featuring a Low Amperage – its arc stability must not exceed 10 amperes
  • Duty Cycle – should ideally be 50 to 80 percent, but it can differ depending on what you need because different manufacturers have found workarounds involving this aspect
  • Pulse Welding – having a pulse mode offers better control in terms of heat

You can also use MIG, but it is a bit more complicated to do so. While there are different types, only pulse and spray arc welding can be used for aluminum. The filler material to be used should also be similar to the alloy being welded. While the shielding gas may vary depending on the alloy, 100% argon is generally recommended. Also, this is preferably done with thin aluminum sheets only due to the amount of heat required.

To be applicable to aluminum, MIG equipment should have the following features:

  • Gas supply – it should be pure argon; the welder must not have a gasless flux core
  • Design – a spool gun that allows the use of a coil with wire or one that has a short Teflon liner and wire feeding system with a smooth roller that is U-shaped
  • Duty Cycle – will depend on your environment; this is crucial especially if the workspace is hot
  • Protection from OverheatingMIG welders are at risk of overheating when used with aluminum, that is why safeguards should be in place

From all these, it is safe to say that TIG is best used with aluminum, but the major issue lies in its operation. Since handling this equipment require skill and experience, only trained users can work with it. If you are not yet familiar with this method, you should use MIG for your work involving aluminum.

What is important is that you avoid methods that require the use of a flux, as it will likely result in porosity in the final result.

What Do You Use TIG For?

Despite MIG seen as more versatile, it does not mean that TIG is limited. In fact, a TIG piece of equipment can be used in a variety of materials and for various purposes.

In particular, this is used with different materials and on projects where precision and control are required. These include:

  • Small, precise welds
  • Critical joints
  • Making different kinds of joints, such as butt joint, T-joint, fillet weld, and lap joint
  • Working on non-ferrous metals, including magnesium, copper, and aluminum alloys, and stainless steel but for thin sections only
  • Tubings with small diameters and thin walls, such as those used for bicycles
  • Aerospace
  • Automobiles
  • Working on conventional metals like copper and nickel alloys, gold, titanium, brass, and cobalt
  • Making repairs
  • Arts and crafts, such as sculpture-making
  • Work that is considered tricky, such as working on round objects and making s-curves

What Do You Use a MIG Welder For?

Compared to TIG, there are more uses for a MIG machine because of the easy handling it offers. Among the many materials and applications you can use it for are:

  • Various metals and alloys, such as stainless steel, silicon bronze, carbon steel, nickel, aluminum, copper, and nickel
  • Joining thin to medium thick materials
  • Creating different joints, including T-joint, butt weld, and lap joint
  • Working in various positions
  • Home and industrial work
  • Doing repairs
  • Pipes
  • Equipment rebuilding
  • As overlay of coating that is wear-resistant
  • Surface reinforcements, such as train tracks that are worn-out

Are you ready for the next step?

We hope that this comparison of the two types processes hasn’t fully scared you off, and that you are now only getting more inclined to get started on your various adventures. 

Whether you are buying a mini metal lathe to get your metal spinning adventures going, you’re getting a fuel transfer tank because you want to increase the capacity of your truck or you’re looking to get started with an oxy torch, there’s no denying that there is a steep learning curve ahead of you, with lots of interesting adventurous, but perhaps more importantly, also a lot of different failures. If you chose the wrong gauge wire for your project, you’ll also end up experiencing a bunch of nasty side effects, but if you chose the wrong type of equipment you may not be able to do the types of projects that you would want either. 

Even if you may be able to choose the type that you are doing in the future, you will probably be saving yourself a lot of headache by starting off and choosing the type that is the most appropriate for the type of projects you are looking for. The good news is that there are some types that may allow you to do various types; whether it is Stick, MIG, TIG or Arc, but there are also some types of machines that will only lend themselves to one type. 

If you are still in the process of doubling down and figuring out what you prefer, you might either want to get a multi process piece of equipment, or you may want to make up your mind already on what to pursue. 

By the time that you start needing to do some more serious work, that initial MIG welder that you thought was going to last you a significant amount of years may not end up holding up to the types of projects that you want to do. The same goes for situations where you may have started out with a very entry-level TIG welder. Soon you may even find yourself looking at something significantly bigger like an engine driver welder that has a lot of additional benefits that you don’t get with the smaller models, like the ability to actually do work without needing to be hooked up to a constant power source. However, when you start looking at these machines, you will also easily end up spending somewhere between $4,000 and $6,000 depending on the needs that you have. 

If you do have the money to choose any type of equipment that your heart desires, there is no question that we would recommend that you start looking into some of the more expensive machines out there, and if you choose to do so, you wouldn’t even have to figure out initially if you have a preference for either MIG or TIG as you could simply get a machine like the Miller Bobcat 250, which is fine piece of machinery that offers both types of processes. However, when you start looking at these bigger pieces of equipment that seems capable of doing any task that you put in front of them, there are certain drawbacks to them, like the fact that they will pretty quickly end up being relatively hard to move without additional assistance. For instance, the Miller Bobcat 250 is a serious machine that weighs 501 lbs, so unless you’re packing some serious muscle and have been doing your deadlifts, you won’t be moving this machine unaided. 

Buying your first piece of equipment

While most people’s first piece of equipment is rarely ever the one that they end up having for significant amounts of time, at least if they are planning on offering welding as a service, there are still cheaper machines out there that may be able to provide the level of functionality that beginners need. 

There are certain limiting factors that may very quickly end up choosing which type of equipment you are looking for, especially if you are doing work outside the more typical types of material than are commonly used. For instance, in order to work on cast iron, you have no option but to choose one with Stick capabilities. 

Because of that, it’s not just important to know the thickness of the material that you will be working on, but also the type of material you will be working on, with TIG being the most versatile option available to you. While MIG may be able to work on some of the most common metals, you’ll soon find yourself at a loss if you’re looking to work on copper and brass but only have a MIG welder. 

To quickly summarize, here are the following types of metal that each of the processes work on:

MIG: Steel, stainless steel & aluminum alloys

Stick: Steel, stainless steel & cast iron

TIG: steel, stainless steel, aluminum alloys, chromoly, copper, brass, magnesium, titanium & exotic metals.

As you can see from the comparison, you are severely limiting the type of work you will be able to do from simply doing MIG. 

Whether you will be working on auto body repair, structural components or general heavy repairs will play a huge role in the selection of your tool of choice. While almost all machines on the market are able to handle the simplicity of auto body repairs, you won’t be able to get the job done when you are working on thick structural components and other types of construction work, if you are working on your uncle’s $500 piece of equipment. For that, you will need something with a lot of amps!

The cheaper the machine you are buying, the lower its duty cycle will also be, as well as the amount of amps it is able to generate. If you have a piece of equipment that isn’t rated at 100% duty cycle at the amount of amps that you will be using it at, you can’t expect to work continuously and will rather need to take breaks to let the machine cool down.

Now that you are aware of the basics of MIG versus TIG welding, hasn’t it become easier for you to choose which one to use for your next project?

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