How to Use a Plasma Cutter

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

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

While 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 does a plasma cutter work, how you can hook it up, which gases to consider, and the steps you need to take to with it.

How does it work?

man cutting thin metal with a plasma cutter

A plasma cutter, first and foremost, is a welding tool for cutting metals. It does this by producing plasma, which is 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 temperature so high that it enters a 4th state of matter. Moreover, 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 a bit 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 capabilities Easy, even for beginners Relatively safe
Fast option No warping Cost-effective
Precise Versatility  

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 straight-forward. 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, carbon steel, cast iron, nickel alloys, stainless steel, and more. And it can do so even with various thicknesses and with different types of metals. 

7. It’s very precise

Plasma cutting allows you to work on non-ferrous metals as well as thick sheets of steel. 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.

How do you hook it up?

Are you ready to start that thing?

First, connect the compressed air to the air filter that can be found at the rear of the machine. Keep in mind that the compressed air could be bottled, 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 will 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 to travel at the correct speed. This way, you can make precise cuts with less dross, which can result in a more refined finish.

What kind of gas should you look into?

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

Pros

  • Efficient with stainless steel and aluminum
  • Minimal chipping during the process.
  • Effective for thin metal sheets with smooth surfaces
  • Cost-efficient

Cons

  • Difficult to make incisions deeper than ½”

Oxygen

If you want high-quality cuts on carbon steel that is at least ¼- 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

  • Requires minimal effort
  • Can be used with other fuels
  • Can generate extremely hot flames
  • Can work fast

Cons

  • The intense heat makes working on soft metals tricky

Oxygen-Air

Oxygen, combined with pure air as a secondary fuel, can create an extremely stable plasma, making 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
  • Effective when intended for thick sheets of metal
  • Makes highly precise results

Cons

  • Poor results when with shiny metals like aluminum

Nitrogen

Planning to cut a lot of aluminum and stainless steel? Nitrogen is where it’s at. It’s especially great for metallic pieces that are up to 3-inches thick, especially when you want 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, making it 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
  • Can be used with a variety of secondary gases such as carbon dioxide, water, and pure air
  • Fast cooling

Cons

  • 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 metal makes contact with it. 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
  • Can be paired with a variety of secondary gases, including water, carbon dioxide, and pure air
  • 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 that are up to 1/2 -inches thick. 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 6” of stainless steel plate. This gas compound is also the best choice for plasma gouging on any material.

Pros

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

Cons

  • Argon can be expensive (it’s a rare gas)
  • Causes occasional chipping and cracking
  • Effective only in controlled settings

plasma cutter in use

What air pressure is required?

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

There are no hard rules as to how much air pressure is required given the different requirements between devices. For example, for most Everlast products, the recommended amount is anywhere between 55 to 70 psi.  Most manuals, however, 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. 

Simply put, 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 efficiently cut the workpiece. If a certain amount is working for you and you’re getting great results out of it, then why not stick with that?

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.

1. Choose a work station

This type of work can be a hazardous job if you’re not doing it on a safe surface. You need to pick a sturdy table that can 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 to a power supply 

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

3. Connect it to the air compressor

If your unit doesn’t have a built-in compressor, connect the external air compressor instead.

4. Turn on the air compressor 

Most compressors have the 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. Plasma cutting, after all, emits potentially harmful electrical charges. Make sure that the ground clamp is attached to the area close to where you’re going to 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

As you work on the metal, make sure that the nozzle is on top of the metal’s edge. 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 simply need to rotate the lever 90 degrees to turn it off.

12. Leave the torch to cool

Done with the cutting? Great job. Now it’s time to let the torch cool off. Once the trigger is released, arrange the hoses and make sure the torch, ground line, and airline are all wrapped up.

Are you just getting started?

There is no denying that it is always an interesting time when you are just getting started playing with a new piece of machinery or tool, no matter if you just added a new fuel transfer tank to your SUV, allowing you to go much greater distances than previously without having to refuel, or whether you just got a wide belt sander that will make a lot of tasks a lot easier at your wood shop, or whether you are thinking about buying a portable sawmill. They’re all considerable expenses, where you probably spent hours doing the necessary research in order to ensure that you were picking the piece of machinery that suits your needs, and a plasma cutter is definitely no different from these other tools that we also offer on our website.

From making sure that you get the best plasma cutter to making sure that you are using it the right way, there are a lot of things that you will need to start thinking about, why we have made guides like this one, as well as the one on the right settings for your oxy torch. It’s the exact 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 metal work, or are you still in the process of looking around?

While there are many pieces of equipment that may be able to do the job that you are looking to do, there are definitely a bunch of them that are a lot better suited to fit your needs than some of the other pieces of equipment.

Have you made sure that you have actually found the type that best suits your needs? Have you figured out which types of metal you are most commonly working on, and what level of capacity you will need as a consequence of it, or are you still researching. Have you managed to find out what are the important things that you should be looking for?

Are you a person who will have it stored in the back of your garage behind that old car that doesn’t drive anymore, while you may only have very modest metal cutting requirements, where you don’t intend on using it more than a couple of per year? If that is the case, your needs are definitely very different from someone who is using it on a daily basis, on pieces of metal with varying levels of thickness. If you want a very clean cut without the need to have to do a lot of cleaning afterwards, you will also have to look at what the machine has been rated for to make sure that it fits the types of metal that you are looking to cut.

While you can get modest machines that might do the job for someone who is occasionally doing some DIY metal cutting, chances are that some of the cheaper machines simply won’t be able to provide the level of power that you are looking for, if you are a person with more serious needs. Yes, you can find cheap models for a couple of hundred dollars, but those are usually not the machines that we are at least offering on this platform, where we tend to tailor our offering of machines to those people that have slightly higher needs.

We do offer a couple of entry-level machines that will still provide a decent level of capacity, but the lowest entry-level machines are ones that you will look for on different platforms than ours. We do believe that they serve a purpose in the market, but we are not intending on selling plasma cutters or any other type of machinery that we do not feel we can stand behind, as we mainly cater to professionals that know they are often spending thousands of dollars on a piece of machinery, obviously hoping that it provides the level of power that they need. Often having very specific needs, these pros turn to our platform knowing that they can rely on the recommendations that we provide.

Whether you’re adding a shower to a half bath, or getting started on gasless MIG welding, we want to be your platform of choice.

When you are getting started, it is equally important that you do your research on the various options, as some of the machines, usually the cheaper ones, have significant setbacks as well.

You should make sure that you truly understand the various features that it brings to you because you may be choosing to save a little bit in the beginning without realizing that it actually ends up costing you a lot more later on, as the machine you purchased has a lot higher operating costs than some of the other machines available in the market. Some of the models are a lot more poorly built, which will usually result in the fact that they are going through expensive consumables at a worrying rate, which you won’t find the more expensive machines doing.

At the same time, you should be looking at things like the quality of the cut that the machine can provide, and what it is rated for. If you are looking at metal with an inch thickness, but your machine is only rated for half that, you will find yourself frustrated.

There are also a lot of people out there that may not want the inconvenience of always having to bring the piece of metal to the machine, but rather want to bring the machine to the piece of metal, why portability may be a very important thing to consider.

Finally, make sure that you have considered the importance of the duty cycle! If you buy a machine that has a very low duty cycle, you’ll be spending yourself just sitting around for long periods of time, if you are planning on continued use of the machine.

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