How to Weld: The Ultimate Guide

Welding basically involves joining together two pieces of metal by heating them until they’re molten so that they solidify as a single unit. Unlike other reversible ways of joining metal together, this bond can’t be broken easily, which is why it’s commonly used for many industrial purposes such as automotive, space, oil, and gas.

We’re going to walk you through the different types of welding, what the basic process involves, and is the easiest welding technique.

Note that whichever type of welding you’re performing, you’ll need an open space to work in to avoid inhaling any of the gases emitted during the welding process.

Different types of welding may use electric current, gas, ultrasound friction, and electronic beams to weld the metal together. We’re going to focus on the most common and safest form of welding – using electric current.

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Important Terms

Before we get into the how-tos of welding, let’s just clear up some important terms to help you understand the process better:

CC- Constant Current refers to welding machines that have limited current and create a negative volt curve, giving them the name “droppers.” While the voltage will vary based on the length of the arc, the current will remain more or less constant. This is usually found in stick and TIG welders.
AC- Alternating current wire feed welding creates an unstable arc with variable current, but this arc is the one that costs the least.
Filler Metal- This is the metal that is melted in the welding arc and melts with the metals being welded to create a binding alloy for an almost irreversible bond.
Shielding- The electric arc of the welding machines needs to be protected from gases like nitrogen in the air that can cause the metal to oxidize. A shielding gas is emitted from either the welding gun or by creating flux. This shielding gas contains argon, carbon dioxide, and helium (known as a tri-mix).
Flux- This is a material that’s a part of the welding stick or is embedded in the wire emitted from the welding gun. This is what gives off the shielding gas during welding.
Stick- A stick in welding refers to a metal electrode that may also be fed to the metals being welded. The stick has an electrode coating known as flux.

What Are The Types Of Welding?

Different welders have their own preferred welding techniques, but there are some basic styles that all of them follow. One common factor in all the styles is that they involve creating a metal pool and pushing (or pulling, depending on the method being used and the welder’s personal preference) an electrode or metal rod through it. You need to work evenly between the two pieces of metal to ensure that they are both properly welded.

There are core welding types and may be used in different circumstances based on the type of metal used and the skill level of the welder.

MIG Welding

This type of welding is the most common one among beginners. Metal Inert Gas (MIG) welding involves generating an electrical current between the two metal objects that need to be joined. A welding wire acts as the electrode to provide the current.

When the welding wire comes into contact with the metal, a complete circuit is created. When the wire is pulled slightly away from the metal, it creates an electric spark that becomes hot enough to melt the end of the metal (the temperature at this end will go up to a few thousand Fahrenheit) of the two objects that need to be fused and the welding wire. Once the welded objects cool down, there will be a visible line (seam) where the two ends meet.

The welding wire is released from a welding gun and is fed to the metals being welded throughout the process as it keeps melting. The welding gun also releases gas to decontaminate the air around and protect the weld from gases like nitrogen, etc.

MIG welding is also known as Gas Metal Arc Welding (GMAW).

How to MIG Weld

Since this is the easiest form of welding, we’re going to take a closer look at it:

The MIG welding machine will have a ground clamp that will complete the electrical circuit between the welder, the welding gun, and the metals being welded. Apart from this, make sure you go through the welder manual thoroughly.

MIG welding is ideal for thicker metals, but you’ll need to manage the voltage properly to avoid burning through the metal, creating metal lumps, or having your metal oxidize.

Make sure that the welder of the gas tank has the right mix of gases at an ideal pressure, and you’re good to go.

Stick Welding

Stick welding is a little more complicated than MIG and is a two-handed job. A metal filler rod or a stick with a flux-coating is required. When heated, this flux coating on the rod melts, releasing gas and turns into liquid slag, both of which protect the metals being welded from getting oxidized.

This gas dissipates on its own, but the slag needs to be cleaned up by dissolving it with solvents and chipping it off with a sander.

Stick welding is also known as shielded metal arc welding (SMAW).

TIG Welding

Tungsten Inert Gas (TIG) welding requires a high level of skill and precision. Similar to MIG, it involves using an electrode, but instead of a wire that gets fed into the welded metals, this method uses a tungsten metal rod in the welding gun. The welder is equipped with a welding gun and a filler rod. Just like with MIG welding, an electric arc is created that melts the metal and filler rod to weld the two metals together. The gun also emits a gas to shield the metal being welded.

In TIG welding, the current running through the circuit can be adjusted via a pedal on the TIG machine. Essentially, this lowers or increases the temperature and keeps the metal from experiencing thermal shock and becoming brittle.

In this process, the welders work in a back and forth motion, constantly dipping the rod in and out of the metal pool created by the metals and tungsten rod melting from the heat.

TIG welding is also known as Gas Tungsten Arc Welding (GTAW).

Flux-Cored Welding

The last and final type of welding of flux-cored arc welding (FCAW). Instead of a wire used in MIG welding, an electrode tube is fed into the metals being welded. The tube has a metal exterior and a flux core. The flux melts due to the heat generated during welding and releases liquid slag and gas to prevent the metals from oxidizing and keep them free from external contaminants. Similar to stick welding, cleaning up this liquid slag is an additional taxing task. However, it is a more reliable way of protecting the metal than the gas emitted by a welding gun.

In this case, the welder uses a pulling motion to keep from welding over the liquid slag- accidentally welding over the slag will make the metal porous and leave small holes in the finished product.

Resistance-Spot Welding

This process involves joining two pieces of metal using an electric current passing through electrodes placed on opposite sides of the metals being welded. The welding of the metals is the result of the metal resisting the flow of current (there is not current arc).

There is no shielding gas required, and this is considered to be one of the easier welding methods. However, its use is mostly limited to sheet metal.

Resistance spot welding is also often known as spot welding.

What Are The Basics Of Welding?

Now that we know the different methods of welding, we need to look at the basic equipment and materials required for the process:

Welding Equipment

Depending on the type of welding being done, welders may go for a MIG welder or the multipurpose welder that works for all four types.

Apart from having the right machine, welders must be equipped with a welding helmet that will keep their face (especially their eyes) safe from the heat, the gases emitted during the process, and any splattered of the liquid slag. Some high-tech helmets also have digital vision screens where you can reduce the brightness to protect yourself from the glare.

Other essential equipment includes leather gloves, sturdy shoes, caps, shirts that cover your arms completely, protective overalls, and so on.

Materials

The essential materials for welding include:

A MIG wire (or a flux core wire, depending on the type of welding you’re doing)
Welding tips
Electrode sticks (or tubes)
Welding gun
Gas or TIG brazing rod

Other equipment that comes in handy during the process includes:

Clamps (or magnets) to secure the metal objects in place as you work
An adjustable welding table and stand to help you work comfortably
Welding blankets to keep the sparks from spreading out too much (these are generally made of fiberglass).

Using Different Welding Methods for Different Materials

You need to consider the properties of the metal being welded before you select the method you’re going to use to weld it. For instance, stainless steel isn’t great at transferring heat, so if too much heat builds up, the steel can get warped and may be prone to a higher chance of getting corroded. In this case, a lesser amount of heat is better – the current can be reduced through the pedal on the welding machine. In order to compensate for the reduced heat, the motion of the welding rod is sped up.

Some metals like aluminum have a lower melting point and are good conductors of heat. They may be very reactive to the air, so you need to take special care to protect them from oxidizing. If an oxidized layer does form, it will most likely have a higher melting point than the metal below, and you’ll need a solvent or wire brush to remove it.

If the metal used in the welding gun is too soft, it may get tangled. To prevent this, guide tubes are attached to the welding gun to guide the movement of the wire.

Prepare the Metal for Welding

If you’re working with old or painted metal, you’ll need to scrape off any paint or rust from the metal. An angle grinder and some high grit sandpaper will help you get the job done. Sand the metal until it’s completely shiny and smooth.

If you’re using an angle grinder, be careful with soft metals that can be molded easily.

Clean up the metal with acetone to remove any dust or dirt from it. Once the metal is free of contaminants, it’s ready to be welded.

Before you start welding, run a clean cloth over the metal surface to remove the remnants of acetone, and you can get started.

Arrange the metals the way you want to weld them – you can use clamps to secure the objects in place so that they don’t move around during the process.

What if you’re new to welding?

If you’re new to welding, there are certain things you need to understand, and it’s a good idea to practice on scrap metal before working on the actual objects that need to be welded.

Start by reading the manual that comes with your welding machine. Fix the settings according to the material you’re using.

If you’re still somewhat new to welding, it may take a bit of practice for you to reach the optimal combination of the voltage and wire speed.

The wire protrudes about ½” inch from the end of the welding gun. Keep the gun around 3/8^”inch away from the work surface. As you start working, you will push the gun forward. In some cases, you can use a pulling motion, but this may cause the shielding gas emitted by the welding gun to dissipate.

You’ll have to be careful about the speed with which you move the gun – this will impact how high the temperature of the metal goes and the amount of welding wire you’ll need to feed in. Many welders use a “whipping” technique to create a consistent speed. It also creates a narrower beaded seam where the two metals meet.

Note that when you’re welding, there should not be any snapping or popping sounds. At most, you’ll hear a buzzing sound as you work (similar to when fat sizzles in a frying pan). Within a few minutes, you should have welded some portion of the metal depending on the size of what you’re working on.

Summary

Welding is no easy task, but then again, it involves melting metal by heating it to a temperature of up to thousands of degrees Fahrenheit. Before you decide to start welding on your own, you will need to be trained properly, know which method works best for the metals you are using, and which method you are most comfortable with.

Before you weld objects of value, practice on scrap metal. Once you’re confident that you can do a clean job without hurting yourself or making the end result look lumpy or full of tiny holes, you’re ready.