How to Use a Plasma Cutter

Cutting metals with precision is a long, tedious process. It’s even more so if you’re dealing with thick lumps. Using saws or angle grinders can only do so much. Suppose you want to speed up the process and produce highly accurate metal pieces. It’s time for you to consider using a plasma cutter from one of our many listed manufacturers. 

They are known for their high-precision and efficient results. Unlike other tools, they aren’t likely to leave “dross.”. It ensures that you’re getting a polished product after the work is done.

Having one as your primary tool for the purpose is highly convenient. You must familiarize yourself with its basic operations before you start using one. 

In this blog post, you’re going to learn some basic information on how a plasma cutter works. You’ll learn how you can hook it up and which gases to consider. We also have the steps you need to take with it.

How does it work?

man cutting thin metal with a plasma cutter

First and foremost, a plasma cutter is a welding tool for cutting metals. It produces plasma formed after combining compressed gas with a high-voltage electric arc. By transmitting the electric arc and the compressed gas through a narrow opening (nozzle), the gas reaches a high temperature and enters the 4th state of matter. This compressed gas runs at very high speeds, allowing it to go through molten metal. 

Awesome, right? You can think of it as a more realistic version of the lightsaber from the Star Wars films. But you don’t have to train like a Jedi Master to wield it. As you’ll soon discover while reading this article, using one isn’t so hard if you know the proper procedures.

Before we go there, let’s talk about why using it is one of the best decisions you can make as a welder.

The advantages

So, why use one in the first place? Because it offers many advantages over other tools, that’s why.

Let’s go over these advantages below:

Advantages
Great capabilitiesEasy, even for beginnersRelatively safe
Fast optionNo warpingCost-effective
PreciseVersatility 

1. It cuts fast

Using one is a great time saver. Did you know that most models can generate 40,000°F? With that amount of heat, don’t be surprised if you’re able to go through metal like a hot knife through butter. 

2.  Easy, even for beginners

When you’re using a plasma cutter, extensive training is not required. Spend a couple of hours using it, and it will feel like you’ve had many years of experience. You see, the operations are pretty straightforward. Before you know it, you’re making perfect cuts with that thing like a real pro.

3. No warping

There’s no warping because the heat-affected zone is smaller.

4. Safer than many alternatives

They are relatively safe. Why? Because they don’t have to use any flammable gases to do their thing, unlike with oxy-fuel torches.

5. It’s cost-effective

You might be surprised to know that creating plasma doesn’t require a lot of energy. This saves you a lot of money on energy costs. Most models also won’t require any preheating, cutting your energy consumption even further.

6. It’s versatile

The tool can cut through almost anything, including copper and carbon steel. It can also take care of cast iron and nickel alloys. That’s just to mention a few! And it can do so even with various thicknesses and different types of metals. 

7. It’s very precise

Plasma cutting allows you to work on non-ferrous metals and thick steel sheets. This is due to the plasma system’s ability to concentrate its energy in a small area. And by increasing the density of the plasma, the tool makes it easy for you to make highly precise cuts.

What kind of gas do you need for a plasma cutter?

There are several recommended types of gas. Let’s go over them one by one. We’re also enumerating their pros and cons to help you decide which one is ideal for your welding project.

Compressed air

Compressed air is the most widely used gas when cutting metal, especially lower currents. This gas is ideal for metals that are around 1-inch thick. Many also choose compressed air because it’s more than enough to create a strong electrical spark that produces a plasma jet.

Pros

  • It’s efficient with stainless steel and aluminum.
  • Minimal chipping during the process.
  • It’s effective for thin metal sheets with smooth surfaces.
  • Cost-efficient

Cons

  • It’s difficult to make incisions deeper than ½”.

Oxygen

If you want high-quality cuts on carbon steel that is at least ¼ to an inch thick, you can’t go wrong with oxygen. Oxygen also delivers when it comes to precision cutting, not to mention that it has properties that make dross easy to remove. You can still use oxygen on aluminum, though you might end up with a rougher cut face if you aren’t skilled enough to pull it off.

Pros

  • It requires minimal effort.
  • It can be used with other fuels.
  • It can generate extremely hot flames.
  • It can work fast.

Cons

  • The intense heat makes working on soft metals tricky.

Oxygen-Air

Combined with pure air as secondary fuel, oxygen can create an extremely stable plasma. It makes it reliable for thick mild steel cuts. Moreover, it goes through metal with stunning precision and leaves little to no debris. 

Pros

  • Oxygen and air are not expensive.
  • It’s effective when intended for thick sheets of metal.
  • It makes highly precise results.

Cons

  • You get poor results when with shiny metals like aluminum.

Nitrogen

Are you planning to cut a lot of aluminum and stainless steel? Nitrogen is where it’s at. It’s especially great for metallic pieces up to 3-inches thick. It’s great to create a polished product with a smooth, shiny surface.

Another great thing about hydrogen is that it produces high-precision cuts despite its economical use of plasma. It’s also equally effective as secondary gas during the process.

Pros

  • It’s cheap (nitrogen is abundant in the atmosphere)
  • It can be used as a secondary gas.
  • Effective when cutting thick sheets of metal
  • Can make high-precision results

CONS

Hydrogen

Hydrogen is a great conductor of heat, ideal for creating extremely hot plasma flames. Despite this, hydrogen has dissociative elements that speed up the cooling process on smoother metals. This gas is also effective for non-heavy metals like aluminum and stainless steel. 

Pros

  • High thermal conductivity
  • Cheap utility and storage
  • It can be used with a variety of secondary gases such as carbon dioxide, water, and pure air.
  • Fast cooling

Cons

  • It can’t be added to other plasma gases during the process.
  • Low kinetic energy 

 

Argon

Argon is an inert gas, which explains why there are no chemical reactions when the metal comes into contact. This is why working on metal using argon as the main compound allows for polished, smoother results.

Pros

  • Kinetic energy is high, resulting in high precision work.
  • Low-ionized plasma beam speeds up the process.
  • It can be paired with a variety of secondary gases, including water and carbon dioxide. Pure air can be used, too.
  • It works well with thin metal sheets with shiny and smooth surfaces.

Cons

  • Has poor conductivity

Argon hydrogen

Argon hydrogen is the recommended gas for stainless steel and aluminum pieces thick to 1/2 inches. The right mixture for argon hydrogen is 35% hydrogen and 65% argon. Thanks to argon hydrogen’s hot plasma gas, this compound helps speed up the process by a great deal. So much so that it can easily go through a 6” stainless steel plate. This gas compound is also the best for plasma gouging on any material.

Pros

  • It produces a nice big flame.
  • It generates intense heat that can cut thick sheets of metal efficiently.
  • It can create clean, refined results, especially when nitrogen is the secondary gas.
  • Results in shiny surfaces

Cons

  • Argon can be expensive as it’s a rare gas.
  • It causes occasional chipping and cracking.
  • Effective only in controlled settings

plasma cutter in use

What is air pressure required for a plasma cutter?

Getting the air pressure right is an important aspect of the process. The plasma will likely blow up if the air pressure is too high. If it’s too low, your plasma won’t be strong enough to do any cutting.

Given the different requirements between devices, there are no hard rules as to how much air pressure is required. For example, the recommended amount is anywhere between 55 to 70 psi for most Everlast products.  Most manuals recommend anywhere between 70 to 150 psi. For low amperage cuts, the required amount is 45 psi and below. Some models have internal regulators, and the recommended amount of air pressure for them is between 60 and 80 psi. 

If you want to know the recommended amount of air pressure, it’s always better to refer to the manual that came with the unit. That doesn’t mean you have to follow it blindly. In the end, it’s up to you to determine how much air it takes to cut the workpiece efficiently. If a certain amount is working for you and you’re getting great results out of it, then why not stick with that?

How do you hook a plasma cutter?

Are you ready to start that thing?

First, connect the compressed air to the air filter found at the rear of the machine. Keep in mind that the compressed air could be bottled. You’ll need a small air compressor or a built-in air compressor. Either way, your unit probably has an in-house regulator that can regulate the system’s airflow. 

Next, set the amperage to the recommended levels. Set the amperage too high, and the workpiece will become too hot and start to gather waste materials. Set it too low, and your work is bound to get sloppy. You don’t want to do either, so turn up the amperage and make some practice cuts to get a feel of things. Then turn it down slowly and stop once you’re comfortable with the travel speed.

The end goal here is for the plasma to have the right amount of heat and travel at the correct speed. You can make precise cuts with less dross this way, resulting in a more refined finish.

How to Use It

Okay, let’s get to the heart of the matter. How do you use one? Here are the steps to do just that.

How to use a plasma cutter

  1. Choose a workstation.

    This type of work can be hazardous if you’re not doing it on a safe surface. You need to pick a sturdy table to support your materials and equipment and keep them in place. Also, pick a location that gives you a lot of wiggle room to move. Make sure the work area is clean. After all, dust and debris may be sucked by the cooling fan and may damage the unit as a result.

  2. Plug it into a power supply 

    Make sure that the tool is turned off before plugging it in.

  3. Connect it to the air compressor

    Connect the external air compressor instead if your unit doesn’t have a built-in compressor.

  4. Turn on the air compressor. 

    Most compressors have a power switch at the rear. Turn it on and wait for the tank to fill.

  5. Attach the ground clamp

    Securing the ground clamp will keep you safe while using the tool. After all, plasma cutting emits potentially harmful electrical charges. Ensure that the ground clamp is attached to the area close to where you will make cuts.

  6. Turn the unit on

    The switch might be found at the rear of the unit. Turn it on and wait for the interface to light up. You’ll notice the air compressor start to engage by then.

  7. Set the amperage

    The thicker the material, the higher the amperage should be. 

  8. Start cutting the workpiece.

    Make sure that the nozzle is on top of the metal’s edge as you work on the metal. Turn the trigger on to create an arc and then slowly move the torch back and forth over the metal.

  9. Turn off the unit

    Once you’re done, turn off the unit.

  10. Unplug the ground clamp from the metal

  11. Turn off the air compressor.

     In most models, you need to rotate the lever 90 degrees to turn it off.

  12. Leave the torch to cool.

    Are you done with the cutting? Great job. Now it’s time to let the torch cool off. Arrange the hoses once the trigger is released and ensure the torch, ground line, and airline are all wrapped up.

Are you just getting started?

Make sure you get the best plasma cutter to make sure you are using it the right way. There are a lot of things that you will need to start thinking about. For that reason, we have made guides like this one. We have also made one on the right settings for your oxy torch. It’s the same way that you wouldn’t want to use the wrong gauge wire size for your 30 amp breaker.

Have you already gotten around to finding the piece of machinery that you will be using for your metalwork? Are you still in the process of looking around?

Many pieces of equipment may be able to do the job that you are looking to do. Many of them are a lot better suited to fit your needs than some of the other pieces of equipment.

Have you made sure that you have found the type that best suits your needs? Have you figured out which types of metal you are most commonly working on? What level of capacity will you need as a consequence of it? There are so many considerations when you start looking for the right plasma cutter.

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