Types of Welding

So you want to learn about the different types of welding but are unsure where to begin?

In this article you’ll learn:

  • A short history of welding
  • A good way to learn the different types of welding
  • An in-depth look at each type of welding
  • Some good welding machines on the market today
  • Basic and advanced tools for a welder
  • Welding Safety

By the end of this article, you may not be an expert welder but you’ll definitely have a basic working knowledge of welding and the different types of welding that are possible. You might even feel more comfortable on a fabrication shop floor!

History

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Let’s really talk about welding! Did you know welding can trace its roots back to the Bronze Age? Ancient people discovered that if you use heat and pressure you can fuse together two lap joints ( two pieces of metal that are halved at the end – creating a joint that lays onto each other) to make items such as boxes. As time progressed blacksmithing was discovered. You may remember that classic picture of a man in a shop near a fire and an anvil pounding down hot metal. Those blacksmiths produced many useful tools for the farms and villages.

Then in the 1800’s progress was being made and laboratory workers discovered how to use the heat of an arc to join lead plates together. Patents for welding were awarded in France and later Great Britain.

Welding as we know it today was discovered in 1890 in Detroit. C.L. Coffin discovered that melted metal can be passed by an arc and deposited into a joint to weld two pieces of material together.

Shielding Gas is Invented

It was not until the 1920’s that research and testing began using shielding gases. Shielding gases are important because without them you can have a weak weld or a lot of spatter. The spatter creates a visually unpleasing weld that may require more work to dress up.

Then during the 1940’s we have the discovery of TIG welding ( GTAW) and later MIG (GMAW) through the research of people like H.M Hobart and P.K Devers and their experiments with various gases.

Lastly, in the late 1950’s Flux core welding was discovered.

Now that we have a brief history of the types of welding, let’s dive into modern welding.

 Modern Welding

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There are 5 major types of welding that we will discuss here:

  • MIG welding ( GMAW)
  • TIG welding ( GTAW)
  • Oxy welding ( OFW)
  • Stick welding (SMAW)
  • Flux core welding (FCAW)

Now, this is not an exhaustive list by any means – there are still processes like EBW or Electronic beam welding, friction welding, and laser welding but we are only going to discuss the most common methods used in factories, shops, and homes around the world.

Where to Start

There are many good ways to learn to weld, and there is no wrong order in which to learn to weld. But in this article we are going to show a specific way to learn them in this order:  Stick welding, Oxy welding, Flux welding, MIG welding and TIG welding. Each one will have pro’s and con’s that we will discuss, and we’ll help you find the best method for you.

The great thing about welding is that each process has its own strengths and weaknesses. As a welder, it’s up to you to choose the right process for your project. Some examples of welding basics are stick for heavier projects. Stick welds are not pretty but usually much stronger than MIG welds. MIG is good for thinner metals but the penetration may not be as good as stick. TIG is great for artistry and commercial applications where a strong weld and a cosmetic appearance is necessary.  Flux core welding is great for the hobbyist, home DIY’er and in factories too.

So the first thing to decide is: what type of welding do you want to do?

If you want to learn all types of welding then follow the order listed here. If you’re just an occasional welder, well, you’ll find a process that’s right for you too and you can start learning it right away.

So now that you’re familiar with the history of welding, the different types of welding processes and your thinking about the type of welding that you want to do, let’s discuss each process in a little more depth.

Shielded metal arc welding ( SMAW)

Commonly referred to as stick welding, this process is very easy to learn. Stick welding produces strong, solid welds and does not require an external gas source like MIG or TIG welding. Stick welding uses an electric current to create an arc between the electrode (or stick – the metal rod that will be heated by electric arc and transferred) and the base metal. The electrode is heated and melted and bits are transferred to the heated base metal creating a weld pool that joins the two metals together.

Shielding

No gas is required in this process because the electricity is converted to heat in the electrode. As the electrode melts the coating (Flux) on the stick a gas is created (shielding gas) that protects the weld from the atmosphere and creates a strong weld. Welds that are not protected could be porous and thus weak. A porous weld is one that has absorbed oxygen or other gases from the atmosphere while its solidifying. As the weld is solidifying the gas that was trapped and absorbed wants to escape – and usually does so, therefore, creating a pinhole in your weld. But many times a porous weld cannot be identified without advanced techniques.

Also, different sticks or electrodes can be selected based on the type of metal and thickness you are joining. A good selection can be found at any welding shop.

Once the weld is laid, the slag (also delivered by the Flux coating on the electrode) rises to the top of the weld and must be chipped off with a chipping hammer. A wire brush can be used to finally clean the weld so you can get a good look at it and make sure there are no issues with the weld. (Visible porosity, low penetration or cracking) Sometimes there is excess spatter around the weld which may need to be cleaned with a grinder.

The Whys of Stick Welding

Now all of this information may sound like a lot, however, there are reasons that stick welding is one of the oldest modern welding forms around – it works! Strong welds can we be created very easily. As your skill level increases, more complex welding jobs can be completed, like pipe welding, and welding at difficult angles. But once you’re familiar with stick welding you’ll find that it is the mainstay of heavy constructing (buildings and office towers) and heavy equipment field repair like trains, trucks and earthmoving mining equipment.

Stick welding, unlike Oxy welding or TIG welding only requires one hand to operate the stick and lay the weld. Also, with stick welding, there is no need to prep your base metal and clean it like in MIG or TIG welding.

Oxyacetylene Welding (OFW)

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The second type of welding we will discuss is oxyacetylene welding. This type of welding uses two tanks, one for a source of fuel and the other tank for oxygen. The fuel and oxygen are mixed and focused on the workpiece to create a metal pool (and more filler metal can be added) to create the weld that will join the work together.

The two gases mix within the handle of the torch and form a flame which the welder holds and places on the joint where the weld is to be laid.  Acetylene burns at a high temperature, anywhere between 3200 to 5300 degrees Fahrenheit – depending on how the fuel is mixed.  One of the primary concerns is the acetylene can be expensive, so to do large production work, such as in factories the cost would add up quickly.

The torch is where the flame is controlled by the welder. Different tips can be chosen to affect the flame size and shape. The flame can be divided into three sections or flame zones, the blue otter tip, the inner tip (or feather) and inner core. The flame is then adjusted with the amount of oxygen added to the mixture – and it generally depends on the type of metal your welding to select the right flame.

The Pool is Key

The metal “pool” or molten metal is created on your workpiece and must be moved along the joint. The pool will move to the point that is the hottest. So you’re always moving your torch a little ahead of the pool of metal, and a weld is created. Now, depending on the size, strength, and location of the weld you are creating you may need to add a filler rod. A filler rod is a piece of metal that you will dip into your metal pool, adding material to your workpiece, therefore, creating a solid weld. This will require two hands, one for the torch and one for the filler metal to be added.

With some practice, it will become second nature. With Oxy welding, you can also heat your metal to bend it and shape it, unlike MIG, TIG or Flux welding. Also, with Oxy welding, you can also braze metal, where you filler metal is melted at a temperature lower than your base metal and the weld is created.

Oxy welding is found in many applications, but it is used to join all types of metals thick and thin because you have such control over your flame settings. It is used a lot in the construction industry, especially in heavy repairs and pipefitting.

Flux Welding ( FCAW)

Flux core welding (FCAW) started to gain popularity in the market around the 1960’s. For this kind of welding no gas is needed. The wire used contains a shielding element inside, so when heated the electrode generates shielding gas. This ensures the weld is solid and protected from the environment. Remember the damage created when porosity is formed?

FCAW welding is used in factories and many DIY welders like it too. In production facilities like automobiles, it minimizes the downtime of changing tanks and the cost of gas. Many flux core machines on the market are great for mild steel that is under 1/4 thick – and that covers most home projects. We will cover some great beginner projects in another article.

Flux core is similar to MIG welding in that you have a torch (or gun) and a trigger assembly. Once your workpiece is set you basically point and shoot to lay your weld. The gun controls your wire feed to the weld and your wire speed depends on the size and thickness of the weld you want to create. The hand speed and control learning in oxy welding will be useful here.

The Advantages of FCAW

The biggest advantage of flux core welding is that it can be used on a variety of metal types that are not too thick. Additionally, strict cleaning or prep of the metals (always recommended for a strong, non-contaminated weld) is not as necessary. Also, since the shielding gas is created by the wire when heated, you do not have to worry about the shielding gas blowing away like you would in a MIG or TIG setup.

This makes flux core welding ideal for use on a job site that may be in a remote location and the metals might be dusty and dirty. Flux core welders are commonly used on farms and industrial outposts where equipment may break down in hard to reach places.

One more benefit of flux core welding is that many of the flux welding machines can be easily converted to full MIG welders. With the simple addition of a regulator, a tank (with CO2/Argon mixture) and filler wire you’ll have a MIG machine ready to go.

MIG welding ( GMAW)

MIG welding (GMAW) is commonly used in factories, lines of production, metal fabrication shops and even by DIY welders. It welding is very similar to flux core in its set up.  There is the welding machine itself, the gas tank, a gun that feeds your wire and your grounding clamp.   When you prep your workpiece, you line up your gun and press the trigger. Your weld is laid on the workpiece and hand speed is important here,

With MIG welding a strong weld is created when you have cleaned and prepped metal. If there is contamination present like dust, oil, mill scale, or rust this could be incorporated into the weld and contaminate it. Thus, causing a weak weld.

One of the reasons MIG welding is present in factories is because there is control over the metal being welded. It can be prepped ahead of time, cleaned and then sent down the line to be welded.

Click here for a Miller Electric video about MIG welding techniques.

MIG welding is preferred in factories and lines of production because high-quality welds can be produced quickly and repeatedly with a minimal cleaning of slag, unlike flux or stick welding.

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TIG Welding ( GTAW )

Now TIG welding or GTAW is very versatile. It can be used on all types of steel, aluminum, brass, copper and most non- ferrous metals. Many consider TIG the hardest to master because it requires the most developed skill level from the operator.

Why it is more difficult

TIG welding is different from MIG and stick welding in several ways. The most noticeable difference is in how you hold the torch and the use of a pedal to regulate your heat.  TIG welding starts off with a small torch that is held between your index and middle finger. Much like one holds a pencil. You select your desired settings and then spark your torch to your base metal and form a pool of molten metal.

Much like oxy welding, you would want to pull that pool forward along your joint and add filler metal. Your pedal controls the amount of heat that is generated through the touch, and how much penetration you can achieve.  TIG welding is an excellent choice for many applications because the welds are strong and consistent when done properly. The Tungsten tip is not consumable as in MIG welding where the wire becomes your filler metal.

With TIG welding you will use your left hand (if you’re a righty) to feed filler metal to your workpiece.   The operator must coordinate their pedal control with their torch control in addition to feeding the filler metal. There is definitely a lot of moving parts to TIG welding. Consequently, you can see why we saved it for last in this article. If you are familiar with basic stick welding, puddle control found with oxy welding, the speed and feed control with MIG welding, you will definitely have the skills to tackle TIG welding.

Types of Welding Machines on the Market

So far we covered the different types of welding, what they can do and the pros and cons of each. Let’s discuss some machines on the market today

MIG / FLUX Machines

As we discussed there are many good flux welders that a DIY’er and occasional welders have used for years. The good thing about Flux MIG welders is that they can be converted to gas if you prefer. Flux welding is great for the occasional welder because you don’t have to worry about a gas set up and the flux will handle lighter gauge steel found in most home projects.

A popular MIG/Flux Welder is the Lincoln Electric Pro MIG 180.

MIG /TIG /STICK combo

This is a really great setup because you can have three types of welders in one machine. Now it’s a bit more expensive than starting off with a simple tombstone welder for stick welding. But if you’re serious about welding this is an ideal setup. You’ll have the MIG setup for quick fabrication jobs with medium and light gauge metals. You’ll have the stick setup for heavier metals and those requiring strong welds like heavy equipment repair and structural applications. And, you’ll also be able to make great looking welds using the TIG setup – idea for cosmetic welds for use on appliances or artwork.

Welding Supplies

One thing to remember about welding is that you will definitely need supplies. Rods are referred to as consumables because the filler metal is used up in the welding process. For MIG welding your consumables will be Flux core or basic steel wire. You will also want to ensure your tanks have enough gas for a welding project, and your LWS (local welding supply) will be able to handle that. In the next section, we’ll talk about grinding stones, pads and finishing materials.

Safety Gear

A word about safety here: All types of welding is inherently dangerous. Everything a welder touches can burn, cut or kill you. Now, that statement is not meant to scare you away from welding. Welding is a really enjoyable process and the pride you feel when you complete your own project is very fulfilling. When safely done, welding is no different than driving a car.

Some basic gear every welder must have is a hood, a jacket and a good set of gloves.

A hood is central for a welder.  Welding emits concentrated UV light that can damage your eyes. You need a hood that darkens when you weld so you can protect your eyes from UV light.  It also protects your face from the sparks and molten metal. A hood should also be comfortable to wear while welding. Read the top 10 welding helmets for beginners review here.

A good jacket will be comfortable to wear and protect your arms, neck, and chest from welding sparks. You can always tell a welder by the holes in his clothes! A good jacket will help you focus on welding and not the sting of welding sparks.

Lastly, gloves are essential. The sparks and heat emitted from any type of welding must be protected against. A good set of heavy gloves for MIG and stick welding can be found here.

For TIG welding a lighter set of leather gloves will help you maintain control of your torch. They will also protect from the molten metal, a good set to consider are these.

Tools

When you start any type of welding some basic useful tools are necessary. Many times you’ll want to fabricate a small project from scratch. That will mean cutting metal stock to size. You will then need to hold the pieces together before tack welding them in place. Once you weld it together you’ll want to clean up or take down your welds so you can inspect them and make your piece ready for finishing.

A good set of clamps are essential for the welder so you can hold together joints and pieces of your project to tack weld together before you lay your weld. Clamps are also useful in the field so you can hold together broken pieces for repair.

Power Tools

Taking down a weld would be impossible without a good angle grinder. They are very affordable right out of the box for a good model like a Dewalt. A nicer model would be a cordless angle grinder. With it, you can maneuver in tight spaces without the restriction of a cord. A good set of grinding stones and an assortment of pads will do wonders, (36 grit to 100 grit is fine to start off with) and will help you take down welds easily.

Also, some other essential tools are a pair of wire snips for the MIG welder and a chipping hammer for the stick and Flux welder. The MIG snips help clip your wire for a clean end after you lay a weld. This is important because a small bead forms on the wire after you lay a weld. And if not snipped, it can jump on your next weld and land on your workpiece, to be cleaned later or even worse land on you! Lastly, I don’t want you to forget a good measuring tape and some soapstone so you can mark your metal where you need to cut, drill or work with.

Advanced tools

So items I want to mention but are not essential to a beginning welder, are items like a good band saw, welding cart, a belt sander, welding table and some heavy duty magnets.

A welding cart is essential in the shop so you can move your tanks and welder around the projects you are fabricating. It would be hard to move anything by hand and not efficient. A good welding table is really worth its weight in gold. A good table will have adjustments so it can be leveled. In addition, it will have a solid surface and a good lip on the edge so you can secure your C clamps and hold down your work. A nice storage rack under your table helps hold shims and a small bit of metal useful during a project, or for future projects.

A band saw will help you cut your stock down to size quickly and easily. Good models have an automatic stop so you don’t have to measure each piece of metal to size. You simply measure your cut length, move the adjustable stop to reflect the correct length then feed your stock through until it stops. It’s efficient and a joy to work with. To see other gear we recommend click here!

Conclusion

There are advantages and drawbacks to every type of welding as we discussed throughout this article. By understanding each welding process you have a better idea of which type would be best for you to learn. Like any good craft, welding takes time and patience to master. With some time set aside every day, you’ll be able to master each type of welding in a short time. Either at home or at a welding school.