Arc Welding: What It Is And How To Do It

Welding has been around since time out of mind. It has come a long way since August De Meritens used arc heat to fuse two metal pieces. Thanks to technological advancements, fusing metals has never been more efficient and easy over the last few decades. A big part of that can be attributed to arc as a method.

What is it?

It is a welding method that uses an electric arc to generate heat. That heat is then used to melt or meld metals. Using a power supply, you can use direct current (DC) or alternating current (AC) to create an electric arc. It’s done between a base material and an electrode (consumable or non-consumable). A power supply has to generate enough heat (around 6500° Fahrenheit) to melt two pieces of metal and fuse them. 

How does it work?

Arc welding aims to fuse metals, and you need the right machine to do that. The power supply creates an electric arc that is hot enough to melt metal. You can guide the electrode holder along the gap line. In contrast, the electrode generates the current that helps produce the filler metal to the said gap.

When metal undergoes extreme temperatures while in contact with oxygen and nitrogen, chemical reactions occur. This is what the arc is for. But the arc does more than that. The arc provides a protective welding gas to reduce contact between the molten metal and the air to facilitate the process. Once the molten metals have cooled down, you get a metallurgical bond that fuses the metals.

Different types

There are many different methods, and the right one for you depends on your objectives and the materials you’re working with.

Let’s go over them one by one.


MIG is a fusion method that feeds a consumable electrode to a metal piece. MIG can either be an inert metal gas or active metal gas. For inert metal gas, you use a chemically inert gas (helium or argon) as a shield that helps maintain the arc.

It is done by using a spooled wire electrode via a spool gun. The gun releases a shielding gas that protects the shielding area from the atmosphere. It prevents the formation of oxides in metals. 

MIG has its share of advantages and disadvantages. Let’s break them down to see if MIG is the right method for you.

Gas Tungsten

GTAW is also known as TIG (Tungsten Inert Gas). It uses a non-consumable tungsten electrode heated at extreme temperatures to meld parent metals. Once two metals are fused, the TIG equipment dabs the material onto the puddle. 

Flux-cored (FCAW)

FCAW is a method that utilizes flux-filled electrode tubes to create electric arcs. The tubes emit flux shields to create a barrier against the air, helping to maintain the electric arc. This type has a high deposition rate. It makes it the ideal method for thicker sections of metal (those that are more than an inch thick).

Plasma (PAW)

This method uses air ion generators to emit hot plasma jets in the direction of the welding area. Jets released via PAW are extremely hot. It creates an ideal environment for welding narrower and deeper results. PAW is also the recommended method to speed up the process.

Shielded metal (SMAW)

This technique uses coated electrodes to generate an arc. Once the heat causes the coating and the tip of the electrode to melt, the alloy slowly solidifies. It facilitates the forming of the weld. This method is ideal for construction work.

Make sure to also check out our article on remodeling a bathroom on a budget.

Submerged (SAW)

This method uses a granular flux to create a dense layer covering the molten metal. SAW allows for deeper heat penetration, unlike a thermal insulator. If you prefer a technique that does away with sparks and spatters, SAW is your go-to method.

What are the differences between TIG and MIG?

The two most popular methods are TIG and MIG. Chances are, you’re stuck trying to decide which method to use. Let’s break down their major differences to help you decide.

One major difference is the method used. As already mentioned earlier, MIG uses a wire electrode to feed the weld. TIG  uses a filler material. If you want to do it fast, MIG is the way. But if you want a refined finish, you’re better off using TIG. 

The best method also depends on the thickness of the metal. MIG is better for working with thicker metals, while TIG is preferred for thinner metals.

You’d do well to use MIG if you’re not experienced as a craftsman. If your skill is at the professional level, then you can leverage that skill by using TIG. TIG is also much more expensive than MIG. 

To help you make an informed decision, let’s break down the pros and cons of each method.


  • Work is more precise.
  • It provides high-quality finishes.
  • It allows you to work on a wide range of materials.
  • It requires small amounts of flames.
  • Works well with thin metals.
  • Resistant to corrosion
  • Beads are visually pleasing.


  • It takes longer to do than using MIG.
  • It is complicated for most beginners to learn.
  • The surface needs to be kept clean.


  • It is done faster.
  • It can be used on a wide variety of metals and alloys.
  • Spatter is minimized.
  • Easy to learn
  • Not a lot of spatter


  • A little expensive
  • Not fit for outdoor work
  • Cools fast
  • Positioning is limited
  • It doesn’t work well with thicker metals

What are the advantages?

Now that you know how it works, you might already have an idea or two about its advantages. Your mind is probably not made up yet on whether this method is for you. Will it be worth it? Here are the advantages of arc welding you should look forward to:

  • Portability. Materials and equipment are lightweight and easy to move around.
  • Affordability. There’s no need to use expensive machinery. You can carry out the process even on a shoestring budget.
  • Refined finish. You get a neat and refined result due to the mechanized nature of the process.
  • Less spark and spatter. When we think of welding, we see a person. His face was covered with a thick mask, sparks flying in front of him. That’s not the case with an arc. A lot less spark and smoke are produced. 
  • Faster process. Because of the concentrated heat it produces, an arc is much faster. 
  • Distortion is reduced. Most beginner craftsmen struggle with distortion caused by a disfigured base plate following extreme heat. Distortion is troublesome because it can compromise the structural integrity of the work. The process reduces much distortion because of the faster process and the higher concentration of heat.
  • Corrosion resistance. Arc produces a welding joint whose properties are non-corrosive. As a result, you don’t need to employ anti-corrosion methods when doing arc. 
  • Joint doesn’t break easily. The joint has higher tensile strength than normal welding and doesn’t break easily.

How to

Now that you have a basic idea of how the process works let’s dive into how to do it. 

Word of caution: When properly installed, using an arc welder is relatively safe. It always pays to be safe. Improper use can expose you to potential hazards. They include:

  • electric shock
  • heat stress
  • noise
  • toxic fumes
  • fires
  • burns

Make sure to wear proper safety gear before you proceed. 


How to use an arc welder

  1. Create a weld.

    You need to create a good weld to ensure a smooth process. First, you need to strike a successful arc between the workpiece and the electrode. Once that’s done, create a bead by guiding the electric arc between the pieces. Then move the arc back and forth along the path until the metal achieves your desired width for the bead. Next, remove the melted slag from the bead until the molten metal looks refined enough.

  2. Make the preparations.

    You need to gather all the tools and materials. Do you have all the equipment you need to perform the work? These include your machine and cables. Make sure you have the clamps and electrodes. Finally, find the metal pieces you’re working on. Make sure that your work area is secure and safe. The table should be made of non-flammable material or steel.

  3. Prepare

    Grind a sharp edge to the sides of the metals to be joined. It gives the arc more room for melting the sides of the metal pieces. Remove any dust and dirt until you have a clean slab of molten metal.

  4. Clamp the metal pieces together.

    Any clamp (spring-loaded clamps or lock pliers) will do as long as it can hold the metal pieces together firmly.

  5. Secure the clamp to the large stock being welded.

    Ensure that the work piece’s grounding is clean to complete the electrical circuit with the least resistance possible. This allows you to create an electrical arc with minimal effort.

  6. Pick the right rod and set the amperage range.

    Put the electrode in the stinger and see that the electrode holder is set firmly at the end of the electrode.

  7. Turn on the machine.

    You’ll hear a humming noise from the power supply as soon as you turn your machine on. Take the time to examine if the cooling fan is running.

  8. Hold the electrode holder and aim the rod’s tip towards the metal plate.

    Ensure the rod’s tip is within a few inches of the metal workpiece. Give it a few practice taps to ensure that you got the positioning right. Caution: You’d want to protect your eyes when striking an electric arc. Make sure that you have your mask on.

  9. Tap the electrode against the metal piece’s surface.

    This can get tricky. The recommended distance between the electrode’s piece and the metal piece depends on the diameter of the electrode and the machine’s settings. But you’ll know you got it right once the machine can generate a continuous arc. See that the arc’s gap does not exceed the electrode’s diameter. Once you’re able to keep the arc steady, gently guide the rod along the area you want to weld. You’ll start to notice the metal melting away. You can begin creating your weld once the pool is filled up.

  10. Maintain the electric arc.

    You need to establish the arc as you move through the weld you’re building. Don’t move the electrode away from the metal piece’s surface, or you’ll lose your arc. Stop what you’re doing and remove the slag from the metal piece if you do. You need to do this to protect it from contamination.

  11. Set your machine’s amperage.

    How many amps do you need? That depends on the type of material you’re working on. Make sure that you reduce the amperage if you see craters starting to form at the edges of the bead. Turn up the amperage if you’re having difficulties maintaining an electric arc.

  12. Clean it up.

    Clear away any slag or dirt once you’re done. Do this because it makes the finished product look better and because it’s good preparation for paintwork. You can remove any remaining slag or dirt by rubbing it with a wire brush or a rough file. You can also use an angle grinder to remove a weld piece. 

  13. Put a primer on it.

    A fresh weld can get corroded if exposed to the elements. To keep the rust away, apply an anti-rust primer along its surface (preferably one in a spray can).

The history

It is very easy to forget the beautiful art of welding, whether you are more interested in MIG or TIG. Often we forget that many of these machines haven’t always been around. Some of the things that can be done with metal weren’t possible a couple of hundred years ago. More simple methods have been used since the Bronze age. There is no denying that the more advanced stuff that is possible today is a new invention.

The skill is only a skill that goes back a couple of hundred years. It all started in 1800 when Humphry Davy discovered the pulsed electric arc. Only 2 years later, a Russian discovered the continuous electric arc. It allowed for many applications, with welding being one of them. The invention was presented in 1881 when Nikolai Benardos presented the technology at the International Exposition of Electricity.

While the truest form of the invention dates back to the year 1,800, there have been major improvements along the way.

Resistance and oxyfuel welding was developed in the early 1900s, although the competition with arc was stiff. During WW2, the technology gained popularity when used with aircraft. It provided a great means to repair airplanes. However, it was also used for building ships.

What is it used for?

Arc welding is commonly used for thicker pieces of metal that need to be fused due to its problem with thinner pieces. Because of how it works, using electricity to create so much heat that the two metals melt can create a binding between the two surfaces. The disadvantage of this method is the level of skill involved.


There are many different manufacturers when it comes to this equipment. There is still one that prides itself on being the biggest in the equipment: Miller Welds. While they do not simply produce welding products, that is their biggest category. They have an impressive reputation in the space with their products!

Don’t go overseas and find a manufacturer with a name you cannot even pronounce. Miller is one of the companies we stand behind. They have an impressive reputation.

Having been around almost 100 years, it is no surprise that they have picked up a skill or two along the way. They have managed to put it into the products that they are producing. It is hard to imagine that this giant started as a one-man company in 1929. They now produce as many different products, including plasma cutters. When you are first getting started with it, their machines are ones that we encourage you to consider. You will see that we even offer recommendations as to our favorite products and why. We want to ensure that you are getting it from the right manufacturer.

When it comes to Stick or SMAW, they have a couple of very popular machines that are also relatively affordable. One of them is the Thunderbolt 160. Among their TIG equipment is especially their Dynasty series that we can recommend!


What is meant by arc welding?

The arc welding process is a way of welding that uses an electric arc to increase the temperature to melt and join two metals together.
This method is very often used among enthusiasts in the field.

The electric arc required to carry out the process arises from an AC or DC electric current source.
This electric arc creates a temperature of about 6500 degrees Fahrenheit.
Using this high temperature, the two metals in contact can melt. Then the joining process is performed.

This electric arc can be moved manually along the welding line between the two metals.
Or it can be moved mechanically along this line, depending on your preferences.

What are the 4 types of arc welding?

There are four main types of arc welding:
– Gas Metal Arc Welding (GMAW) or MIG
– Gas Tungsten Arc Welding (GTAW) or TIG
– Shielded Metal Arc Welding (SMAW) or Stick
– Flux-cored Arc Welding (FCAW) or Flux-cored
MIG is often used in the following areas:
– vehicle repair
– house and building construction
– This type of method is one of the most widely used of the four.
TIG is often used in the following areas of activity:
– aerospace
– car repairs
An electrode made of a material called “tungsten” is used in this method.
STICK is most commonly used in the following areas:
– construction
– general repairs
– underwater pipe repairs
– industrial manufacturing
An advantage of this method is that it is entirely portable.
This may help if you need to make some repairs while on the road.
Flux-cored is most often used for the following purposes:
– For welding thicker metals.
– In the processing industries.
– This method is very similar to the one represented by MIG.

How hot is a welding arc?

The temperature of a welding arc can reach up to 6500 degrees Fahrenheit.
This high temperature is required for the process to work correctly.

A high temperature is needed to melt the two metals to be welded together.
These two metals are brought into contact.

The welding arc is applied to the point of contact.
The metals will melt following this contact.

After a while, the temperature of the metals drops. Their welding takes place.

What happens to metal during welding?

Following the welding process, specific physical properties of the metals involved can be altered.
One of these physical properties is strength.

The strength of a metal that goes through this process can be drastically altered.
Suppose the welding process is performed at too high a temperature.

In that case, the basic chemistry of the metal may be altered and its strength reduced.
The ideal temperature will depend on the type of method chosen.

The hardness of a metal is another physical property that can be affected by this process.
A welding process can drastically reduce a metal’s hardness if not performed at an optimal temperature.

Ductility is the property of a material to remain permanently deformed or stretched after the appliance of an external force.
If the welding process is not performed correctly, the metal may lose this property.

Why is a weld so strong?

A weld of two metals has a high degree of strength because it involves the direct bonding of the two metals.
In the soldering and brazing processes, two pieces of metal are joined together using a third material.

This third material will always have a lower melting temperature than the other two metals.
This material is positioned between the two metals to bond and is melted through exposure to high temperatures.

After cooling, the two metals are joined together.
But the strength of this joint will always depend on the type of material used to make it.

If the material used to make the joint has a low degree of strength, the newly created joint will also have a low degree of stability.
On the other hand, it is no longer necessary to use a third material to achieve the joining of metals in a welding process.

The two metals are melted at their common point of contact and then glued together after the temperature drops.
This type of bonding will have a high degree of strength, depending on the resistance of the metals used for welding.

Did you like this article?

We’re happy to inform you that there are many other articles we also encourage you to read up on. Check out this page, where you can find the plasma cutters that we recommend. We also have a page where you can find the right engine-driven welder for your purpose. See all the things you need to be aware of when buying one.

Did you like this article? Do you have any recommendations for additional topics you would like us to cover? We often create welding resources based on the various things that we find interesting. We are also very open to covering topics our site’s users provided to us. Some of those topics even end up becoming incredibly popular. This article on the right settings for an oxy-acetylene cutting torch is an example of it.

There are different types of welding. Take the time to make sure that you understand the advantages and disadvantages of each welding method. The various types will each have their pros and cons. The right decision for you regarding equipment may not be the right decision for someone else. For example, TIG will usually produce stronger results than MIG. It is also harder to learn initially.

We hope that it will give you some ideas about where you can continue your search. It’s even if you have not found the right welding type!

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