AC and DC are two kinds of electric currents that offer different characteristics, features, and benefits. But it’s tough to decide which stands out in MIG welding, especially when comparing Ac vs. Dc Mig welding.

So, this guide is all about their noticeable differences, functions, pros, cons, and which ultimately beats the battle.

AC or dc for mig welding
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What are AC and DC in Welding?

Alternative current, aka AC, and Direct current, aka DC, are known as different forms of current utilized in the process of welding.

For welding thinner objects or materials, most of us use direct current (DC), while alternative current (AC) suits high-frequency, TIG, and heavy-plate welding. Each has its unique characteristics, including pros and cons.

Differences between AC & DC Current Flow in Welding Machine

Tons of differences can be noticeable when comparing the direct and alternating currents. Some of them are as follows: 

  • DC is able to weld almost every type of electrode, while AC can suit coated electrodes and some specific choices. 
  • The initial charge of direct current is relatively higher than the alternating current. 
  • Unlike DC, the welding output of AC is smoother. 
  • Compared to direct current welding, the maintenance cost of alternative current is slightly lower.
  • DC tends to produce less spatter, while AC generates more spatter as usual.
  • Compared to the AC, the arc of direct current is more stable measured by seasoned welders. 
  • DC is highly suitable for vertical and overhead welding. In contrast, the AC matches the flat welding position most. 
  • Last but not least, direct current arc welding tends to be noisier than the alternative current.

Advantages and Disadvantages of AC in Mig

Both benefits and drawbacks can be noticeable when considering choosing the alternative current for Mig welding. Some of them are listed below –


  • Even if you choose any magnetic material for MIG welding, the AC comes in handy
  • Alternative current is compatible with aluminum MIG welding as well.
  • For joining thick meal pieces while MIG welding, AC is a good choice for sure.
  • Unlike the DC, AC appears to be more portable and affordable.
  • AC Mig welding can reach long distances in the best way possible.


  • Unfortunately, you’ll have to deal with more spatter
  • Beginners may lose overall control while welding through AC Mig
  • The alternative current’s arc for MIG welding is relatively less stable

Advantages and Disadvantages of DC in Mig

Just like the AC, the direct current also has some pros and cons. Let’s check them out –


  • During Mig welding DC, you’ll find the welding output much smoother and stronger
  • Unlike the AC, DC tends to offer even better control over the Mig weld.
  • The direct current produces a low spatter compared to the alternative current.
  • Even for Mig welding thinner materials, DC arc is an ideal choice.
  • It penetrates deeply as well as the rate of deposition is pretty faster while Mig welding.


  • Unlike the AC, the DC arc welding process isn’t much lightweight
  • You can’t get most of your aluminum welding through the DC arc
  • Compared to the alternative current, the direct current is more costly

AC or DC, Which One Is Suitable for Mig Welding & Why?

As you can see, both AC and DC have their own unique specialties, pros, and cons. So, deciding which one stands head and shoulders above the rest is a bit tough.

However, considering some key aspects, I’d like to share my personal view on which one is more suitable for MIG welding.

Overall, the direct current or DC has more advantages or benefits than AC in terms of Mig welding.

Ask me why?

Because it tends to produce less spatter yet let you achieve smoother welding output.

Moreover, the direct current is able to weld multiple types of materials, including thinner metals, to get your job done. And yes, this will penetrate more deeply, along with ensuring a quick deposition rate for Mig welding.

But if you want to weld aluminum through Mig welding, then don’t be a fool to choose the direct current instead of the alternative current.

Besides, if your budget is extremely low yet needs to MIG weld thick materials, then you can simply rely on the AC. But that isn’t going to be your best decision if you have enough budget and welding experience; keep it in mind.

How to Set Mig Welder in DC Mode?

To be honest, very little authentic information is available for setting Mig welder in DC mode.

So, for your convenience, here are the 5 effective steps to set up your MIG welder in DC mode –

Step-1: Cable Observation

First off, ensure each cable connection isn’t loose and is totally free from damage by checking out your welding equipment.

Step-2: Electrode Polarity Setup

As you know, the mig weld needs the direct current’s positive electrode (+). You can find a polarity connection right inside the machine.

Step-3: Gas-flow Setup

Let’s switch on the shielding gas in terms of setting the overall flow rate. This should be around 20-25 CF/hour.

Step-4: Tension Observation

You may end up with the worse wire feeding in case the tension appears too little or too much. So make sure to adjust it following the users’ manual.

Step-5: Consumables Experiment

From each contact tube, feel free to take off the additional spatter you notice. And if the liners or contact tips appear worn, replace them as soon as possible. It is okay to cast away the wire if you find it rusty.

Last Words

The battle of Ac vs. Dc Mig welding was quite head-to-head. As each has its own unique benefits and drawbacks, you can’t consider any of them the “BEST!”

That said, I’ve found the DC more suitable for MIG welding due to its smooth welding output, deep penetration, and quick deposition rate.

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Maidul Islam

I am Maidul Shakil and am a welder for more that 6 years. Welding metals and joining them is my hobby and passion. I have learnt all welding techniques, safety issues, fabrication process and rigging from SUNY Westchester Community College . I am now trying to teach beginners about welding to encourage them to come to the field.

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