mig welders

Are MIG welders AC or DC?

Are MIG welders AC or DC? It’s an important question to ask…

Welding can be a handy skill to learn, and if you’re an employer whose team undertakes welding for manufacturing or maintenance works, you’d understand its importance. However, those who aren’t boilermakers by trade mightn’t understand a few critical facts that make a difference when acquiring new machines either via hire or sale. 

MIG welders are a popular choice thanks to their many operational benefits. They can be used for a range of applications because they have the ability to bind a wide selection of metals, however, in terms of industry, you will most commonly find a MIG welder in the automotive, construction and high-production manufacturing industries, such as those who make computer or marine components.

When looking for industrial MIG welders for sale or hire, you’ll want to understand the essentials and the first thing to know is, are MIG welders AC or DC?

AC or DC – what’s the difference?

Let’s start with the basics. AC and DC refers to the movement of electrons through a conductor. DC stands for ‘direct current’ and is where the electric charge flows in a single direction only. On the other end of the spectrum, AC stands for ‘alternating current’ which, as its title describes, facilitates the current as it changes in different directions periodically.

So, are MIG welders AC or DC? Almost every MIG welder that you find on a worksite will be operating in DC output.

This is due to the lower frequency and more precise handling that is usually required when performing a weld. But this doesn’t limit the machine’s ability. In fact, MIG welders can run AC output, however, it is rarely needed as the higher voltages associated with AC are typically used to transmit electricity over much larger distances. For example, powering a house full of appliances. 

More about AC and DC for MIG welding

Now that we’ve addressed the question, “are MIG welders AC or DC,” we’ll take a closer look at more important MIG Wwelding details…

While AC is usually a secondary choice in welding, there are a few instances where it would be preferred. For example, some smaller machines only offer only AC as an output option. While this might seem like a drawback, AC welders are usually cheaper than DC welders which is ideal for entry-level welders.

AC also offers superiority when welding magnetic materials because the alternating current allows for a steadier arc. AC’s high temperature abilities also means it’s preferred when welding materials at higher temperatures, such as aluminium, or when requiring deeper penetration.

On the other hand, DC predominantly produces a smoother welding output compared to AC. This is because of its more stable arc which results in easier welding and significantly less clean-up. 

DC output also allows for different functions such as positive or negative polarity. DC positive polarity is useful when a high level of penetration is needed to fuse hard metals such as steel. While DC negative polarity equals less penetration at a higher deposition rate, suitable for use on thinner metals such as sheet metals of various compositions. 

Take a look at Renteca’s range of MIG welders here. https://renteca.com.au/product-categories/mig-welder-rental/ 

The pros and cons of DC

While a MIG welder will typically operate in DC mode, you’ll also find DC used in many other forms of stick welding, including some TIG welders, especially when a TIG machine is being used to bond stainless steel. That’s due to DC’s nimble abilities in ensuring high quality, precision welds across a wind range of metals. 

While DC has its perks, there are some things to consider, too. 

You may notice that DC machines are usually a little more expensive. This is because DC currents typically require an internal transformer that switches the current between polarity modes. Welders will also find that arc blow can’t be corrected while DC welding, and that DC doesn’t perform optimally when welding aluminium due to its inability to produce the necessary high heat. 

welding equipment

We’re pleased to answer your welding questions here at Renteca, including, “are MIG welders AC or DC?

That’s because at Renteca, welders are our passion. From compact units to heavy duty machines, Renteca has the equipment that is suited to your needs. With each product maintained by highly skilled factory-trained technicians, Renteca welders represent premium value. 

Used welders for sale come with a warranty in partnership  equipment depending on the manufacturer with Cigweld and ESAB – either Lincoln Electric or Miller Electric. 

You can browse some of Renteca’s range here, including our range of industrial MIG welders for sale. To speak directly with a member of our friendly team to find out which machine is right for you, request a call back here.