How To Setup And Use Your MIG Welder For The First Time

If you’ve bought your first MIG welder and are unsure how to prepare everything for your welds to stick, we’ve got you covered! MIG welding is relatively easy, even for beginners. All it takes is a proper equipment setup and some basic skills to weld most DIY projects. 

This article will teach you:

• How to set up your MIG welder
• What shielding gas to use and how to attach it to your machine
• How to select the welding wire and how to install it
• How to hook up all of the cables and which polarity to use
• Individual settings most MIG welders have
• Basics of MIG welding for beginner-level DIY projects

Got your welding helmet ready? Let’s get started!

Welding Safety

We weren’t kidding about the welding helmet. If you don’t have one, you’ll need one. Welding produces dangerous UV and IR radiation that can seriously damage your eyesight. On top of a welding helmet, you’ll need gloves rated for MIG welding, not TIG welding, because MIG welding will expose you to more molten spatter particles, so get yourself a pair of robust leather gloves. In addition, you will need a welding apron, welding boots, and a pair of welding pants. Always make sure that your workspace is free of anything flammable, have a fire extinguisher ready, and don’t weld in a room without proper ventilation. 

Heat Resistant Welding Gloves

YesWelder offers a range of auto-darkening welding helmets designed for professional and hobbyist applications. Our helmets look good too! So, you’ll look and feel like a superhero as you fuse cold, hard steel.

Atomic Dice x YesWelder | The Aggressor Q800D

YesWelder The Larry Q800D Graphic Monster Welding Helmet

MIG Welding Theory

Metal inert gas, or MIG for short, is an arc welding process. And like all other arc welding processes, it melts and joins the base metal with the filler metal using the resistance of current flow through the metal. When electricity flows through the metals like steel, stainless, aluminum, copper, and others, the materials resist the flow of electrons, which creates heat and melts the material if the current flow is high enough. Some metals like carbon steel are easier to melt because they have a high resistance to current flow, while metals like copper readily accept electricity flow, and it takes more electricity to melt them.

The power source, your MIG welder, prepares the electricity according to your settings and lets it flow through the MIG welding gun and into the MIG wire that sticks out of the MIG gun. Once this electrically charged wire comes into contact with the welded metal, the current makes a full circle: power source > MIG gun > ground clamp > power source, and flows through this circuit. However, the metal (wire and the base metal) resists the current flow and heats up to the point of melting, which fuses the materials together. That’s the essence of how MIG welding works.

Setting Up Your MIG Welder For the First Time

Now that you’ve grasped the basics of how MIG welding works and how to protect yourself using personal protective equipment (PPE), let’s discuss how to set up everything from the moment you open the box of your new welder to the first welds.

We strongly recommend reading the operator’s manual of your MIG machine, especially the parts about the safety and limitations of the welder. 

You’ll typically find the following contents in the box:

• Power cord - usually pre-installed on the machine
• MIG gun - some YesWelder units come with a pre-installed graphene liner for welding steel or aluminum

How to Change a MIG Gun Liner - YesWelder MIG 250 Pro

• Ground clamp - used to complete the circuit for welding
• Consumables like contact tips
• Drive rollers like U, V, and W - we’ll discuss these in the section about wire setup
• Spool gun - typically bought separately if your welder supports it. A spool gun is used for welding aluminum without any risk of wire entanglement. 

YesWelder® 150AMP Spool Gun | Aluminum Welding Gun Torch

Shielding Gas

MIG welding requires the shielding gas to protect the molten weld from atmospheric contamination and oxidation. But, the shielding gas also influences the weld quality and characteristics — mainly the arc stability, spatter, depth of penetration, and bead width. 

It’s essential to use a suitable MIG welding gas for a particular metal you are welding. Shielding gas selection is a topic on its own, but to make this beginner guide as approachable as possible, use the following recommendations at face value:

• Welding carbon steel requires either a 100% CO2 shielding gas or a mixture of 75% argon and 25% CO2. The 75/25 is the most commonly used shielding gas, and you can find it at any local welding gas dealer. Avoid pure CO2 for thin metal because you are more likely to burn through it.
• Welding stainless steel works best with a Tri-mix of 90% helium, 7.5% argon, and 2.5% carbon dioxide. 

MIG Welding Stainless Steel with Tri Mix Gas (90% Helium, 7.5% Argon, 2.5% CO2)

Source: https://www.youtube.com/watch?v=Z75xvCrVwpc

• Welding aluminum requires a 100% argon shielding gas, but you can add some helium for improved penetration.

You’ll also need a shielding gas regulator if you already have a welding cylinder. This regulator is attached to the shielding gas bottle, and its job is to regulate how much shielding gas pressure is released for the flow over the weld puddle. 

Thread the shielding gas regulator carefully on the shielding gas bottle and tighten it snuggly. Stay clear of the regulator’s way in case the regulator is faulty because the gauge on the regulator may explode and harm you. Always carefully read the safety instructions for using the shielding gas regulator and the pressurized gas bottle safety tips from OSHA. Once the regulator is set, establish the line between the regulator and the MIG welder with the hose.

Source: https://www.youtube.com/watch?v=IcIkucgzcto

Welding Wire

You can use a solid filler metal wire to MIG weld in the true sense of the word, or you can use a self-shielded flux-cored wire to join metal with the flux-cored welding process. 

• Solid metal MIG wires require a shielding gas, as described above. 
• Flux-cored wires quite literally have a flux inside their hollow core which protects the molten weld pool from the atmosphere. You don’t need to use a shielding gas if the wire is a self-shielded flux-cored wire.

Select a MIG wire that matches the type of metal you are welding. You can see the available solid wires from YesWelder in our chart below:

Solid MIG Wire Selection Chart
Wire Thickness	Welded Metal
	Carbon Steel	Stainless Steel	Aluminum
			4043 Alloy	5356 Alloy
0.030”	YesWelder ER70S-6	-	YesWelder ER4043	YesWelder ER5356
0.035”	YesWelder ER70S-6	YesWelder 2LB ER308L	YesWelder ER4043	YesWelder ER5356

Use smaller diameter wire for welding thinner sheets of metal and larger wire to weld thicker sections. 

Before installing the wire spool in your machine, you must ensure the correct wire roller is installed in the wire drive system. Use the V-groove (smooth wire guides) roller to feed the solid MIG wire and the W-groove (serrated wire guides) for flux-cored wires. 

Image showing the wire feeder components.

To change the wire roller, you will need to loosen the tensioner, lift the guiding roller up, unscrew the plastic cap that holds the main roller (V or W), and replace it with the one you need for your wire. In addition, each of these rollers has two guiding lines, one is for the 0.030” wire and another for the 0.035” wire. So, you need to set the roller for the wire size as well. 

 How to change the wire roller: 27:25-28:20

FIRSTESS MP200 User Guide | YesWelder

To install the spool of wire, remove the large plastic “knob” to get to the plastic post with the guiding pin. Next, take your wire spool and slide it onto the plastic post so that the guiding pin goes through the dedicated hole on the wire spool. In addition, your wire spool must be installed so that the wire unwinds from underneath into the wire drive mechanism. Never install the spool by unwinding from above the wire drive; that’s just a bad practice that leads to poor wire tension, tangling, and other issues.

Before attempting to install the spool, make a firm grip over the wire and hold it firmly as you are installing it in your MIG welder. If you release the wire, it can easily unwind rapidly before you get the chance to manually guide the end of the wire through the wire drive system and into the MIG gun. 

Image showing the correct wire tension. If you tighten the wire too much with the tensioner, it may not feed properly into the MIG torch.

Once you push some wire into the MIG gun liner, lower the upper roller, and latch it up with the tensioner. It can be challenging to push the tip of the wire into the MIG gun liner as you are holding the wire to prevent sudden unwinding. However, you can hold the wire with one hand and use a screwdriver or a similar tool to precisely manipulate the wire’s tip into the MIG gun liner.

Polarity

You need to select the correct polarity for MIG welding. Your standard MIG setting requires a DCEP (direct current electrode positive) polarity, while Flux-cored welding requires a DCEN (direct current electrode negative) polarity.

 

Two common ways to switch polarity on the MIG machines are via a bus bar or wire connection inside the filler metal wire compartment, or by using the DINSE plugs in front of the machine to switch polarity.

YesWelder MP200 5-in-1 welder & cutter User Guide

If you own a welder like the YesWelder MP200, you’ll need to manually switch the bus bar connection inside the spool wire compartment to the “+” sign for MIG welding, and to the “-” sign for Flux-cored welding.

MP200's bus bar connection inside the spool wire compartment

However, if you own a welder like the YesWelder MIG 205DS-B, all you have to do is attach the pre-installed DINSE plug on the front of the unit to one of the DINSE sockets right next to it. To MIG weld, connect the plug to the “+ positive” DINSE socket, or if you wish to use a Flux-cored welding process, plug it into the “- negative” DINSE socket. This will change the polarity of the wire in the MIG gun. But, you must also attach the ground clamp to the opposite DINSE socket to complete the circuit, so the ground is connected to the negative DINSE connector to MIG weld, and positive for Flux-cored welding. 

Change the polarity: 3:45-4:01

Yeswelder MIG-205DS-B Multi Process Welder Review and Test

MIG - DCEP	Gasless Flux-Cored - DCEN
Wire Drive Lead (Pre-installed on the front of the unit) attaches to the positive DINSE socket	Wire Drive Lead (Pre-installed on the front of the unit) attaches to the negative DINSE socket
Ground clamp attaches to the negative DINSE socket	Ground clamp attaches to the positive DINSE socket

MIG Welder Settings

Your MIG machine can have a lot of settings or only a few, depending on the brand and if it’s a hobbyist machine or for professional work. 

Our YesWelder MIG machines are typically loaded with features, regardless if you are a hobbyist or a full-on professional working in the field. 

We’ll quickly explain the most prominent MIG welder settings to help you use your machine to its maximum capabilities. But, we can’t dissect every feature in tiny details because this text would be too long.

So, let’s start with the most important settings — the voltage and wire feeding speed.

Voltage, Amperage, And Different Modes of Arc Transfer

Besides the filler metal deposition rate, arc’s heat, and depth of penetration, adjusting your voltage and amperage (in the case of MIG welding, that’s your wire feeding speed), you’ll also set your metal transfer type.

The two basic metal transfer types are short circuit and spray transfer for MIG welding. 

The most common MIG settings for voltage and wire feeding speed (WFS) will put you in the standard short circuit MIG transfer. The short circuit mode basically melts the wire at the point of contact with the welded joint many times a second. The wire from the MIG gun touches the metal, creates a short circuit which causes the resistance to current flow to grow rapidly. As a result, the wire’s tip is melted into the joint, and the process keeps repeating as the MIG gun pushes more wire to cause a short circuit with the welded material. This arc transfer method is identified by a lot of spatter and the standard MIG sizzling sound like bacon frying in the pan. 

But if you raise your voltage and WFS substantially, you’ll enter the spray arc transfer mode. Every machine has slightly different settings you need to use to enter the spray arc transfer, so you have to experiment a little on a piece of scrap metal. You’ll recognize entering the spray transfer once the arc doesn’t produce a spatter, and the process makes high deposition of the filler metal rapidly. In addition, the spray transfer produces a more quiet, hissing arc, without the crispiness associated with the short circuit mode. 

The required voltage and WFS settings are also influenced by the wire’s diameter and the welded metal. So, thicker wires require more current. 

Typically, you would use a spray transfer mode when welding thick joints or doing out-of-position welding, and short circuit MIG for welding thin sheets of metal. While this satisfies most welding needs, welding costly stainless steel thin sheets of metal is not ideal if the short circuit spatter harms the appearance of the welded part. 

So, to use the best of both worlds, you can use pulsed MIG welding. In a nutshell, pulsed MIG oscillates between the high amperage needed for penetration and the low amperage that keeps the puddle cool to prevent burn-through. The high amperage portion of the pulsed arc provides the spray transfer mode, so there is little to no spatter, but you are less likely to burn the thin stock thanks to the low current part of the cycle. You can learn more about how pulsed MIG welding works here. 

Other MIG Welder Settings

Let’s start with the Synergic MIG setting, the most helpful and the most impactful setting found on YesWelder MIG machines. 

The Synergic MIG reduces much of the guesswork when it comes to the voltage and WFS settings because it automatically adjusts both according to your selected amperage or material thickness. As a result, even a complete beginner can have a good starting point when setting up their MIG machine. Of course, you can always adjust your settings manually by turning the Synergic MIG off and adjusting the voltage and WFS independently to fine-tune the arc transfer to your liking.

 

Synergic MIG setting

YesWelder MIG-205DS-B Multi-Process MIG Aluminum Welder

The wire diameter selector button allows you to select the wire you’ve installed in your machine to optimize the power output for that specific diameter. 

One particular setting many people don’t use to their advantage is the MIG inductance setting. YesWelder MIG machines include the inductance setting, which you can manually set to produce a softer arc with less spatter or improve penetration and arc force. Fine-tuning the inductance can help you when welding thin sheets of metal, you don’t need maximum penetration, and when reduced spatter is desirable.

MIG Welding Basics

Once you attach your MIG gun, select the polarity, install the wire, connect the shielding gas hose from the regulator to your MIG welder, and put on your PPE, it’s time to lay the first welds!

It’s best to weld scrap metal before attempting to weld something valuable. Making several practice welds will help you establish the welding speed you are comfortable with, and you can tailor your voltage, WFS, and MIG inductance to align the welding arc, filler metal deposition rate, and welding speed to your liking.

While MIG welding plain carbon steel is relatively tolerant to some work contamination, it’s best to pre-clean everything with a wire brush or an angle grinder. Your welds will look better if you remove mill scale, rust, and shop oils from the steel. In addition, a clean metal surface provides better conductivity for your ground clamp so the arc will be more stable.

Source: https://www.youtube.com/watch?v=H25zxJ-9y78&t=169s 

To achieve better penetration, drag the MIG gun away from the weld pool so that the wire is pointed back into the bead. But if you weld thin gauge, you can use the push technique and push the gun ahead of the bead to reduce penetration and lower the chance of burn-through.

Hold the MIG torch with both of your hands to improve precision and stability, keep the wire to work distance consistent at about 3/8 to 1/2 in, and keep the torch as straight as possible. 

You’ll achieve better results on thin metal sheets if you first space out your tack welds before welding the seams. Evenly spaced tack welds prevent warping and hold the pieces in place before you place the final weld along the joint line. 

Tack Welding

Source: https://www.rapiddirect.com/blog/what-is-tack-welding/

However, if you are welding thick sections, use the spray transfer mode we discussed earlier to achieve a higher deposition rate and deeper penetration.

If you don’t feel comfortable welding right off the bat once everything is ready, you can practice by dragging/pushing the MIG gun along the joint line without initiating the arc to practice your hand position and movement in order to figure out the best body and hand position that works for you. We advise making your first welds sitting behind a welding table so that your other hand rests on the table with the elbow and forearm while its palm supports the main hand that drags the gun. That way, you’ll eliminate hand tremors and have more control over the MIG torch. 

Source: https://weldguru.com/push-or-pull-when-mig-welding/

One mistake many beginners make is a loss of MIG gun angle as they travel along the joint. So, their torch begins close to perpendicular to the joint line, but the nozzle ends up almost parallel to the work surface by the time they reach the end of the joint. Such welds often suffer from porosion because as they lose the MIG gun angle, the shielding gas can no longer cover the weld pool from above. It’s essential to keep your MIG gun consistently pointed over the weld pool, so it’s a good idea to practice your travel action until you get the hang of it.

Conclusion

You should be able to get good at MIG welding relatively quickly. This process is designed for ease of application and maximum productivity. While TIG welding often offers better results, it’s the MIG welds that carry the weight of the world, so to speak. Most of today’s fabrication and manufacturing relies on MIG welding because it’s fast, efficient, and straightforward. So, it’s no surprise that the MIG welding process is the hobbyist’s favorite, and we hope this guide brought you one step forward to welding becoming your hobby or a full-time job!

👏 You may be interested in the following:

• MIG Welding Aluminum For Beginners
• How to get the strongest flux-core weld
• How To MIG Weld Stainless Steel Like a Pro