The Battle Of Ac Vs Dc Welding (2021): Which One Is Best?

Which one is more STABLE, Ac or Dc welding?

It’s a question that drives you nuts, right?

Can’t BLAME you!

Welding is a vast field. And most probably you are a starter. No wonder, the term AC/DC looks like rocket science to you.

Don’t you just hate it when it’s puzzling?

Well, let me help you. AC is basic welding, used brazing and Carbon Arc welding. It’s upgraded into DC power, improving the ease of welding first.

Still not convinced?

Keep reading, and you’ll find out the arc welding basics stuffs about industrial equipment and the difference between ac vs dc welding.

Difference between A.C and D.C welding machine: An in-depth comparison

Look:

Welding is the joining or connecting of two or more metal parts normally by melting them together. Like any electrical current, a welding arc has a polarity, designed with a positive and negative pole.

I know you are getting bored and disturbed why I am touching this technical term like polarity, but This Welding Arc Polarity is closely related to Ac and dc welding.

So what is Welding Arc Polarity?

Polarity has a significant effect and the strength of a weld. Meanwhile, Electrode-positive, also known as reverse polarity causes a penetration then electrode-negative polarity (reserve). So usually there are two types of polarity.

• welding reverse polarity
• welding straight polarity

Straight and reverse polarity is so common term in Arc welding.

Get it?

In most of the time, DC is the preferred welding polarity. Now let’s see what the difference between Ac vs dc welding machine.

In a hurry? Check out the quick comparison table then.

Point	AC Welding Machine	Dc Welding Machine
Size	Small in Size	Larger in Size
Weight	Light in Weight	Heavy in Weight
Price Range	Reasonable	Pricey
Arc Blow	Comparatively Easy	Difficult to Control
Operating Cost	Cheaper	Higher
Voltage drop rate	Less	High
Energy consumption	3 to 4 kWh	6 to 10 kWh

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1. Overview of DC welding

“A great option for beginners learning the welding”

DC refers to direct Current, a process where the charge travels in only one direction and returning a constant polarity. As I mention earlier, in welding there are mainly two electrode connections. These are:

• Current electrode positive (direct)
• Current electrode negative (direct)

Hence, Electrode negative or straight (DCEN) is faster in its process, as well as the melt-off of the electrode is relatively quick.

So have we got that straight?

The straight current produces less heat than the positive electrode. That’s why it is used widely on thinner substrates.

What is the dc welding machine working principle?

In DC reverse polarity method, the electrode is positive; on the other hand, current flows from its workpiece to the electrode.

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Advantages of dc welding

• Less splatter
• Easy to start
• Less sticking/ outages
• Better with vertical welding
• Leave a smoother arc
• Great for thinner metals

Downsides of DC Welding

• Not well enough to fix arc blow.
• More expensive
• It’s doesn’t work well for high-intensity heat.

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2. Overview of AC welding

AC refers to Alternating Current where the electric charge moves in one direction half of the time and then for the other half flows in the opposite direction. (Portable welder guide)

Can’t understand anything?

In plain words, the flow of electrons always keeps switching directions and going back and forth. Hence, it can even change its polarity 120 times; yes it’s for per second.

Now let’s be honest.

AC should be a secondary CHOICE in welding. Of course, there are a few instances where AC welding would be preferred. For example, entry-level, low cost, machines sometimes run only AC power.

Let’s see the advantages and disadvantages of ac welding machine.

Advantages of AC welding

• Magnetized materials
• comes at affordable price
• For use on aluminum
• Highly portable

Disadvantages of AC welding

• Creates more spatter
• Don’t expect smooth cut as DC

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Distinct contrasts between Ac vs Dc welding

There are some big differences that have a big impact on whether the Ac or dc welding is right for you.

First, let’s talk about size. AC machines are small in size. As a result, weight is also pretty light. On the other hand, DC is relatively larger, weight is also pretty heavy.

Now come to Voltage drop. In A.C welding machine, the Voltage drop in A.C. is less, therefore can be used at large distances. On the contrary, the Voltage drop of D.c is relatively higher and can be used at a short distance.

Wait, there is much more.

Where DC has a higher operating cost, AC machine is comparatively affordable.  Meanwhile, less electric energy consumption need for per kg of metal deposited on AC welding.

The uses and applications make a huge difference between the two. With the A.C. power supply, only a few machines can be used which need low power factors.

Types of welding using AC

1. TIG welding aluminum
2. In shipbuilding
3. Downhand on heavy plate

On the other hand, DC can be used anywhere with machine engine driven D.C. generator or even by rectified A.C. supply.

See the difference?

In a word, it supports a good amount of machine and more versatile. Have a look at the Types of welding using DC:

1. Cast iron
2. Overhead
3. Vertical
4. Sheet metal
5. Rivets
6. Heavy aluminum
7. Arc bronze rod
8. Low hydrogen

The last one but not least, the maintenance of AC welding is more economical and easier than DC.

So which one is best?

As we can see, both come with some particular areas where each one will be UNBEATABLE. So AC and DC welding are used for completing different tasks.

But yes, in most cases, DC welding machine is more advantageous compared to AC welding. Hence, in certain cases, classic AC will also be a better choice.

No matter what you choose, don’t forget to use the best welding gloves and protective gear like a welding helmet.

Frequently Asked Questions (FAQs)