Arc Welding: What It Is And How To Do It

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

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. By using a power supply, you can use direct current (DC) or  alternating current (AC) to create an electric arc between a base material and an electrode (consumable or non-consumable). Of course, 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 needthe right machine to do that. As the power supply creates an electric arc that is hot enough to melt metal, you can guide the electrode holder along the gap line while the electrode continues to generate 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. To facilitate the process, the arc provides a protective welding gas to reduce contact between the molten metal and the air. 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

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

MIG 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, which 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

Gas tungsten arc welding (GTAW), also known as TIG (Tungsten Inert Gas) uses a non-consumable tungsten electrode heated at extreme temperatures to meld parent metals. Once two metals are fused, the tig welder 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 weld-metal deposition rate, making 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, which creates an ideal environment for welding narrower and deeper welds. PAW is also the recommended method if you want 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, which 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 that covers the molten metal. SAW allows for deeper penetration of heat, not unlike what a thermal insulator does. If you prefer a technique that does away with sparks and spatter, 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 while TIG  uses a filler material. If you want to do it fast, MIG is the way to go. 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 the better choice if you’re working with thicker metals while TIG is preferred for thinner metals.

You’d do well to use MIG if you’re not experienced at 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.

TIG PROS

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

TIG CONS

  • Takes longer to do than using a MIG welder
  • Complicated for most beginners to learn
  • Surface needs to be kept clean

MIG PROS

  • 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

MIG CONS

  • A little expensive
  • Not fit for outdoor work
  • Cools fast
  • Positioning is limited
  • 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. However, 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 covered with a thick mask, sparks flying in front of him. That’s not the case with arc welding, where a lot less spark, spatter, and smoke is produced. 
  • Faster process. Because of the concentrated heat it produces, arc welding is much faster. 
  • Distortion is reduced. Most beginner craftsmen struggle with distortion, which is caused by a disfigured base plate following extreme heat. Distortion is troublesome because it can compromise the structural integrity of the work. The process, however, reduces much of the distortion because of the faster process and the higher concentration of heat.
  • Resistance to corrosion. 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 welding. 
  • Joint doesn’t break easily. The joint has higher tensile strength than normal welding and therefore doesn’t break easily.

How to

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

Word of caution: When properly installed, using an arc welder is relatively safe. However, it always pays to be safe. The improper use of it can expose you to potential hazards such as electric shock, heat stress, noise, noxious fumes, fires, burns, etc. Make sure to wear proper safety gear before you proceed. 

Equipment

  • Welding Machine (equipment can either be A.C. or D.C.)
  • Cables or Leads
  • Electrode Holders
  • Cable Connectors
  • Chipping Hammer
  • Wire Brush
  • Protective Gear (gloves, work boots, glasses, apron)

1. Create a weld

You need to create a serviceable 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 of the weld 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

Next, you need to gather round all the tools, materials, and equipment you need to perform the work. These include your machine, cables, clamps, electrodes, and metal pieces. Make sure that your work area is secure and safe. The table should be made of non-flammable material or steel.

3. Prep your weld

Grind a sharpened edge to the sides of the metals that are to be joined to give the weld arc more room for melting the sides of the metal pieces. Remove any dust, dirt, grease until you have a clean slab of molten metal.

4. Clamp the metal pieces together

Any clamp (i.e., spring-loaded clamps, lock pliers, or a vice) 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 to it 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 tip of the rod towards the metal plate

Make sure the tip of the rod 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 so make sure that you have your mask on.

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

This can get tricky since the recommended distance between the electrode’s piece and the metal piece depends on the diameter of the electrode and the machine’s amperage settings. But you’ll know you got it right once the machine is able to generate a continuous arc. See to it 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. If you do, stop what you’re doing and remove the slag from the metal piece. 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 not only because it makes the finished product look better, but also because it’s good preparation for paintwork. You can remove any remaining slag or dirt by rubbing at it with a wire brush or a rough file. You can also use an angle grinder if you want to remove a piece of the weld. 

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 that welding is, no matter if you are more interested in MIG or TIG. Often we forget that a lot of these machines haven’t always been around and that some of the things that can be done with metal weren’t possible a couple of hundred years ago. While 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 very new invention.

The same way that fuel transfer tanks, portable sawmills and wide belt sanders are relatively new inventions, so is the craft of fusing metals.

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

However, 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 were being developed in the early 1900s, although the competition with arc welding was stiff. During WW2 the technology gained popularity when it started being used with aircraft, providing a great means to repair airplanes, although 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 together due to its problem with thinner pieces. Because of the way that it works, by using electricity to create so much heat that the two metals melt, it can create the binding between the two surfaces. The disadvantage with this method, however, is the level of skill involved.

Manufacturers

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

Rather than going overseas and trying to find a product from a manufacturer that has a name you cannot even pronounce, this is one of the companies that we stand behind here on the website, given their impressive reputation.

Having been around almost 100 years, it is no surprise that they have picked up a skill or two along the way and managed to put it into the products that they are producing. It is hard to imagine that this giant started out as a one-man company in 1929, and that they now produce as many different products as they do, including plasma cutters. When you are first getting started with it, their machines are definitely ones that we encourage you to consider, and if you move around the platform and use the various links that we have made available, you will see that we even offer recommendations as to our favorite products, and why. While we do want to sell some of the equipment that we have available here, we also want to ensure that you get the piece of equipment that matches your needs, why we want to ensure that you are getting it from the right manufacturer as well.

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

Did you like this article?

If you liked this article, we’re happy to inform you that there are a bunch of other articles we also encourage you to read up on, including checking out this page where you can find the plasma cutters that we recommend. We also have this page where you can not only find the right engine driven welder for your purpose, but can also see all the things you need to be aware of when buying one.

Did you like this article, and do you have any recommendations for additional topics that you would like for us to cover? While we are often creating welding resources on the basis of the various things that we find interesting, we are also very open to covering topics that are provided to us by our site’s users, and some of those topics even do end up becoming incredibly popular on our website, like for instance this article on the right settings for an oxy acetylene cutting torch.

However, as there are different types, our recommendation is that you take the time to really make sure that you understand the advantages and disadvantages of each of the various types, especially if you are about to buy a new piece of equipment. The various types of welding will each have their pros and cons, so the right decision for you when it comes to equipment, may not be the right decision as for someone else. For example, TIG will usually produce stronger end results than MIG will, but it is also harder to initially learn.

Even if you may not have ended up finding the right type of welding on the basis of this article alone, we hope that it will give you some ideas as to where you can continue your search!

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