Arc vs Mig Welding, What’s the Difference?

For centuries, joining pieces of metal was a tedious task requiring heat and hammering. However, with the invention of welders, it has become easier than ever before. They have evolved so much in such little time that the process is accessible to anyone wanting to learn. But the two most common are Arc and MIG welding, so what’s the difference?

Arc and MIG welding are different processes of welding metals. They both use electricity to heat metal, but the way they work is very different. Arc welders use a continuously heated electrode that moves along with the current arc, while MIG welders use a constantly heated fed wire electrode to form a bond.

There are many differences between arc welding and MIG welding. Knowing the difference can be difficult for those just starting, but this article should clarify any questions you may have. At the end of the article, I list my favorite Arc and MIG welders.

Arc Welding

Arc welding is one of the most common types of welding. It uses electricity to melt and fuse metal parts using an arc between two electrodes. This process was created by Nikolai Benardos, who presented his work at an international fair called “The International Exposition Of Electricity” in Paris back in 1881.

How Arc Welding works:

Before moving further, you should understand how arc welding works. An arc welder uses a power supply, either an alternating current (AC) or a direct current (DC), to generate an electric current that flows through an electrode.

When the electrode comes in contact with base metals, it produces an arc that creates intense heat, melting metal and forming a solid bond when cooled. Often a liquid coolant is used to cool down fuses. A consumable or non-consumable electrode is used depending on the situation. Shielding gas is also used to protect the weld.

Types of Arc Welding:

Gas Tungsten Arc Welding: This process uses a non-consumable tungsten rod as an electrode for welding. It is used for thin sheets of metal but gives accurate results and a shiny finish.

Carbon Arc Welding: Uses a non-consumable carbon electrode that heats metal plates for welding; filler metal can be added if required.

Plasma Arc Welding: It is pretty similar to Tig welding, but the difference is that electrode is placed inside the torch’s nozzle, and high-speed plasma is emitted from the copper nozzle of the torch. You can use it to weld different thicknesses of metal pieces by controlling current.

Shielded Metal Arc Welding: Shielded Metal Arc Welding is a manual process that uses an electrode filled with flux. It is simple to use and has a high demand in modern construction industries.

Fluxed-core Arc Welding: It uses an electrode filled with flux. It is used for welding thick metal plates. And has a high deposition rate. I wrote an in-depth article about Fluxed-core arc welding you may find helpful.

Submerged Arc Welding: In this welding process, a layer of powdered flux is used for welding; it helps to transfer heat for better penetration and protects the weld.

Which type of arc welding is the best?

All these types of arc welding have different capabilities, but Tungsten Arc Welding (Tig) is more versatile and productive than the others. It gives the strongest bond while maintaining quality, It is a time-consuming process, but it gives precise results even on thin metal sheets, which is worth it. It is also the best choice for welding aluminum pieces.

Tungsten arc welding is the best choice among the different types of arc welding because it provides a strong bond and can be used to weld various materials. It is used to weld thick metal and can produce precise results on thin metal sheets and aluminum.

Mig Welding

Now let us talk about MIG welding, which uses a consumable wire electrode to fuse metal parts together. Mig’s most notable feature is the use of carbon dioxide as shielding gas; however, it wasn’t until much later that this technique became popularized and used by welders worldwide.

Mig welding was created at the Batelle Memorial Institute and was initially only used to weld aluminum and other light alloys because of the high cost of Inert gases. But in 1953, Lyubavshkii and Novosiloov found a way to use semi inert gas carbon dioxide as shielding gas which caused a massive revolution in the welding industry.

How Mig Welding works

Typically a Mig welding machine consists of a DC power source to supply an electrical current, a ground clamp, gas tank, and a welding gun from which a thin wire is continuously fed to the welding pool.

The wire from the welding gun also acts as the electrode and heats the metal parts when the circuit is complete and direct current flows through it. Direct current electrode positive (DCEP) and direct current electrode negative (DCEN) are used depending on welding requirements.

These are a little more technical terms that are important to understand if you’re a beginner; they describe how the electrode is used when welding. If you connect the electrode to the positive terminal, the polarity is designated as DCEP. If you connect it to the negative terminal, the polarity is selected DCEN.

AC source is also used, but for limited situations only. Alongside the wire electrode, a shielding gas is also emitted through the welding gun to protect the weld from contact with atmospheric gases. The gas is controlled with a pressure valve connected to the gas tank.

Which one to choose, Arc or MIG welding

For specific applications, you may need to choose between Mig or Arc welding. The pros and cons for both processes will depend on what kind of metal you are working with and the size of the project. Some key differences can help decide which one would be best suited for your needs.

Experience

Arc welding is the most common type of welding; it is widely used but difficult to master at the same time. It produces slag, which makes it harder for beginners to handle. While MIG weld is easy to perform and can perform all tasks using a single welding torch, you only have to click the trigger to start and stop.

Usability outdoors

Arc welding is less susceptible to external factors such as wind or dirt making it a good option for outdoor welding. On the other hand MIG welding outdoors isn’t advisable because wind interferes with the shielding gas making it difficult or impossible to weld correctly.

Thickness of material

Arc welding can be used for almost all sizes of steel or stainless steel plates. It has better penetration power and can weld thick metals at a fast pace. While Mig welding is limited to a few materials, it has the upper hand because you can use it on thin metal sheets and get precise results. It is a better choice for aluminum than arc welding.

Weld Quality

Both Arc and Mig welding produces strong weld, but arc welding produces slag while Mig welding gives clean and shiny weld.

Cost

The arc welding machine is significantly cheaper than Mig welders, and it gets most of the work done. Its device is also portable as it doesn’t require a shielding gas. While if you have a heavy budget and want more controls, you should go for Mig welding.

Best Arc Welders

There are many good-quality arc welders in the market, but we have selected a few we like for you to consider. You can check out the prices on Amazon to get a baseline on how much arc welders and MIG welders cost before shopping other places.

Hobert Stickmate 160i:

The Hobert Stickmate 160i is our top arc welder. It’s lightweight and runs of 120 or 240 volts for those working on thicker metal welds. The prices for this versatile machine are reasonable considering its capability.
Lightweight, quick arc start, wide amperage control & Dual Voltage (120 & 240 V)

Lincoln Electric AC-225

Lincoln has a solid reputation in the welding industry. The Lincoln Electric AC-225 is a durable basic machine that will give you years of reliable service. It has a wide amperage range and is easy to operate, runs on 225 amp AC.

Lotos LTPDC2000D

The Lotos LTPDC2000D is a multi-purpose welder that offers excellent versatility. Over 400 Amazon customers wrote reviews on this machine and gave it exceptionally high ratings. I suggest you take a look at what they have to say before you buy a new welder.

Best Mig welder:

There are a lot of good MIG welders on the market; some are from newer manufacturers, which I have no experience with but from reading reviews, they look like they are good options. I typically don’t mind trying a new machine so long as it comes with a warranty and a 30-day money-back guarantee.

Hobart, Miller, and Lincoln all create high-quality Mig welding machines; you can choose any of them without having to worry about quality or customer service; each of them stands behind their products.

Hobert Handler 210 Mig

I like all Hobert Handler MIG machines; this one is especially nice because it can produce a nice weld using your household power. Plus, it’s easy to use and move around. More than 1,000 customers have written reviews on this welder and given it 4.8 out of 5 stars.

If you’re in the market for a 240 volt MIG welder, check out the Hobart – 500553 Handler 210 MVP MIG Welder, which you can use with either 110v or 240v.

Forney Easy Weld 261, 140 FC-i Welder, 120V, Green

The Forney Easy Weld 261 is a great little machine to keep around the house. It’s perfect for small jobs and is lightweight enough to move around with ease, plus it’s simple to use. It is only a 140v machine so don’t expect it to work like the bigger ones.

The Forney machine has received over 2,000 reviews and almost 80% give it 5 out of 5 stars. I encourage you to read the reviews before you buy any machine, often you’ll learn something about the product you didn’t know.

Lincoln Electric LE31MP MIG Welder with Multi Processes

Affordable, portable, easy to use, good for beginners and mid-level welders, Single V (115V). The Lincoln Electric LE31MP MIG Welder sold on Amazon is a refurbished machine tested and certified to look and work like new.