Informational Guide

How To Use A Mig Welder

Learn how to use a MIG welder like the professionals. Our complete guide showcases all the in’s and out’s of using these tricky tools.

After you find the best MIG welder for beginners, you want to know how to use it. We review how to use a MIG welder and offer tips that allow you to work like a professional. If you are just getting started with a welder, you want these practical tips.

Before you learn how to use a MIG wire feed welder, you should first understand what the machine does.

MIG welding, otherwise known as gas metal arc welding, is a process that forms an electric arc from a wire electrode to the workpiece metal, allowing materials to fuse together.

You can use it with a variety of materials, such as stainless steel, magnesium, carbon steel, aluminum, copper, nickel, and other alloys.

gas welding

Components of a MIG Welder

The MIG welding unit is made up of several components you must understand before using. We recommend reading the owner’s manual when you want to know how to weld using a MIG welder.

The welder contains the electrode spool that creates the anode. Rollers push electrode wires into the welding gun. The MIG wire varies in size based on the type of metal you are working with. You will also need a gas tank to source the inert gas needed for welding.

Finally, the ground clamp completes the short circuit between your workpiece and the electrode wire.

mig welder components

MIG Welding Preparation Procedures (Safety Advice)

Before you learn how to use a Lincoln 140 MIG welder, you must protect yourself.

Metal Preparation

Dirty metal is not strong and won't create a strong bond. You must clean your metal before welding if you want a secure bond. There are several methods for cleaning the material, including using an angle grinder, sandpaper, or wire brush. Determine what's best for your project based on material type.

Equipment preparation

Before you learn how to use a gasless MIG welder, you must prepare all of your equipment. Gather all of your supplies and do a physical inspection of the welder. If there are any worn or damaged parts, you want to replace them before you start welding.

Wire selection

You need to choose the appropriate MIG wire for your welding project. In most cases, you are going to use ER70S-3 or ER70S-6, but it’s important to research the right wire for your material and purpose. Otherwise, you won’t be able to create the beads needed to join your materials.

Gas selection

Welding gases play different roles in the process, from creating arc stability to offering weld penetration. The most commonly used shielding gases are argon, carbon dioxide, helium, and oxygen. Depending on your needs, you might prefer to use a mixture of the above elements. Your supplier might have recommendations based on the project you are working with.

Understanding Voltage & Amperage

The amperage is relative to the wire size you use. For the most part, you will use these wire thicknesses with the following amperages.

  • 0.023 inch: 30-130 amps
  • 0.030 inch: 40-145 amps
  • 0.035 inch: 50-180 amps
  • 0.045 inch: 75-250 amps

Voltage further determines the width and height of the bead. A shorter arc decreases the voltage and yields a ropey, narrow bead, where a longer arc and more voltage tends to produce a wider, flatter bead.

How to Use a MIG Welder (5 Easy Steps)

You can learn how to use a MIG welder on YouTube, or you can read through our helpful hints below. We will cover some of the best practices allowing you to focus on proper welding techniques and creating the solid joints you need.

1. Getting the Heat and Feed Settings Correct

As we discussed above, you must have the right machine settings if you want to achieve the best weld. Ideally, you will start by reading through the owner’s manual, which should indicate what settings you want for each type of material. Most applications require a gas flow rate between 20 and 25 cubic feet per hour. You can also learn how to use a gasless MIG welder on YouTube.

2. Start with Practice Beads

If you know how to use a Lincoln MIG welder, you know how important the practice part is. You shouldn’t need to practice any further unless you are a beginner. Try out the varying techniques on scrap metal to see what works best for you. Many people prefer to use the pushing technique, but you might also try the pulling option instead. You will also need to know the proper angle to complete your weld.

3. Knowing the Different Welding Positions
  • Flat Position Welding
    The flat weld requires you to place material directly on the joint. You can use a back and forth method when filling larger gaps. If you are creating a flat joint, you want to hold the gun at a ninety-degree angle. This is also helpful for the butt weld, T-joint, and lap joint.
  • Horizontal Position Welding 
    The horizontal weld requires you to lower your gun angle, which keeps the filler from sagging. Use your normal pull or push angle, but utilize a back and forth weaving motion when filling in the larger gaps. While the amperage would remain the same as your flat weld, you might need a smaller wire to keep the pool from getting too large.
Overhead Position Welding

The overhead weld relies on techniques from standard welding but with an increase in the travel speed. With the excess speed, you prevent any filler from falling from the joint. It’s also possible that you will need to increase the gas flow rate.

  • Vertical Position
    With a thin material, you want to use the vertical down technique when you start at the top and move with gravity. However, thicker materials require the vertical up technique where you start at the base to increase penetration.
4. Welding Metals Together
  • How to use a MIG wire feed welder
    Wire feed welding is the same as MIG welding. You must join metal together by heating up the material and feeding the filler metal electrode with your electric arc. You will also need shielding gas that protects the metal from contamination coming from the environment.
  • How to use a Gasless MIG welder
    If you want to know how to use a MIG welder gasless, it helps to purchase a reliable, highly-rated machine as many aren't meant to work with thin materials. Once you get the appropriate welder, read the owner's manual, and familiarize yourself with a how to use a gasless MIG welder video.
  • How to use a Lincoln MIG welder
    The Lincoln 140 welders are some of the most popular on the market. Thankfully, Lincoln makes it simple to get started with any of the welders, beginner, or advanced. You can read through the owner's manual or search through Lincoln’s website to find the information you need.
  • How to use a MIG flux core welder
    If you weld outside or with dirty materials, you want to know how to use a MIG flux core welder. While the process is slightly different, you will find that learning how to use a MIG flux wire welder isn’t much different from what you already know. We recommend the following video.
5. Grinding Down the Weld

If you aren't worried about the appearance, you can skip this step. Otherwise, you want to grind the area to clean it up. Do this carefully, or you could cut the weld and damage your material.

Tips & Techniques For Beginners

You can find a cheap MIG welder to get started with, but you want to use it safely. Here are just a few tips to get you started when you need a solid weld.

  • Stabilize your grip.
  • Don’t neglect the value of cleaning your materials before welding.
  • Double-check your ground.
  • Determine when to use a pushing or pulling technique.
  • Match the size of your electrode wire to the job.
  • Always wear protective materials.
  • Practice on scrap materials first.

Common Challenges When MIG Welding


If this welding problem is caused by an improper surface condition, you can clean the material to remove contaminants. You might also be struggling with the shielding gas coverage, which requires using a flow meter to check your settings.

Lack of fusion

A consumable that hasn’t adhered correctly to the base metal might leave a fusion problem. When you have a lack of fusion, the weld becomes weak and could cause structural issues. Fusion trouble occurs when the metal in your pool is melted, but you can’t get enough energy to fuse it to your base plate. To fix the problem, check your voltage and amperage settings.


The unfilled end of a weld creates a crater. It occurs when the arc stops too soon. By allowing the crater, you permit a weak bond that could break. To prevent craters from occurring, you want to allow the weld puddle to fill before you stop the arc.


Melt through occurs when the weld metal penetrates through the base metal. It happens most often when working with thinner materials. To prevent burn through, you want to turn down the amperage when welding thin materials and keep the base metal from becoming too hot.

Dirty welds

A dirty weld can be caused by many problems. You might have contaminants on the material that need to be cleaned, or your polarity settings might be wrong. To determine the cause, you might want to start with the basics and walk through the steps once again.

Wire burns

Burn back is a common occurrence, resulting when the weld forms in the contact tip. You run into trouble when the wire gets fed too slowly or your MIG gun gets held too closely to your base metal. Consider increasing wire feed speed or lengthening your distance between the gun and workpiece.


Tangled wire creates a mess that commonly happens when MIG welding. The trouble could be related to improper wire feed setup, incorrect tension settings, using the wrong rollers, or using the incorrect tip size. Check all of your equipment and settings again to ensure you are set up properly.

electric welding

MIG Welding Terminology

Wire stick-out

Stickout is the part of the nozzle where the wire melts off the end. Stickout and electrode extension are only used interchangeably if the contact tip is flush with the nozzle end.

Push or pull

Pulling leads to a deeper penetration, but pushing creates the flat weld that covers more of your surface area.

Travel Speed

This speed is the linear rate of the arc moving along your workpiece. The travel speed dictates the level of bond and security of the weld.

Travel angle

This angle is relative to the gun with a perpendicular position. In most conditions, you have a travel angle of 5 to 15 degrees, as anything more can lead to spatter, arc instability, and less penetration.

Work angle

The work angle illustrates the gun position in relation to the welding joint angle. It varies based on joint configuration and position.

Flat position

The downhand position is the easiest to use, allowing the metals to be joined flat against one another.

Horizontal position

This more difficult position creates a horizontal weld axis. With a fillet weld, the bead is placed where the pieces meet at a ninety-degree angle, while the groove weld faces along a vertical plane.

Vertical positions

Both the plate and weld lie vertically with this position. However, molten metal can flow downward and pile up as a result. Sometimes, welding upward prevents this from happening.

Overhead position

This is the most difficult position with two pieces of material located above the welder. The welder must be angled properly to reach the joints.

People Also Ask (FAQs)

Can you MIG weld without gas?

The only time you should MIG weld without gas is when you use a flux core welder. Other wire types require the use of gas as a shield.

What kind of gas do you use for MIG welding?

MIG welding relies on four gas types – argon, carbon dioxide, helium, and oxygen. Each one provides a unique benefit, as well as certain drawbacks.

What causes excessive spatter in MIG welding?

Most commonly, welding spatter is caused by an excessive wire feed speed, but it could also have to do with the metal composition, contaminants, a lack of shielding gas getting to the weld, and any coating on the metal.

Is MIG welding easy?

MIG welding is the easiest form to learn, often called “hot glue gun” welding. Once you master MIG welding, you might be ready to upgrade to a TIG welder.

What current is used for MIG welding?

Unlike other welding processes, MIG relies on one standard voltage and polarity type – DC. Direct current is the same as what is found in your car battery.


Once you understand the basics of MIG welding, you will be amazed at all the projects you can complete at home. Work safely by understanding what’s involved and get started on your next project today.