There are quite a few ways you can cut steel and other metals. Grinders and saws are both popular ways to get the job done. Chop saws and cut-off wheels make it easy to cut your materials reasonably quickly. But, the fastest and most accurate way to get the job done though is by using a plasma cutter.
Plasma cutters can be used to cut a variety of different size and shaped materials, including—tubing, thin sheet metal, and 2-inch thick plates. Using a plasma cutter allows you to make accurate and precise cuts. The tool helps you cut through your materials like a warm knife through butter.
If you’re never used this tool or simply need a quick refresher, this article will help you understand everything you need to know about using a plasma cutter and how to do it safely.
Plasma Cutting 101
Plasma cutting is a process used to cut pieces of metal using a machine and torch. Way back in the 1960s, engineers discovered a way to use their electronic welding machines to cut materials. Rather than joining pieces of metal together, the same machines could be used to cut materials instead. This was accomplished by turning up the gas and speed of the welding machine to a point where it began to cut materials.
This eventually led to the invention of the torch and the machine used today to complete these operations. Today’s plasma cutting machines use an electric arc and compressed air to complete cuts. You’ll find this tool used in metal shops, garages, and construction job sites across the country. Plasma cutting is one of the most effective ways to make quick and accurate cuts.
Types of Plasma Cutting Machines
There are two main types of plasma cutting machines. In most garages and shops, you’ll find the standard option, which includes the plasma cutting machine and external compressor. On some job sites, though, you may come across plasma cutting machines with a built-in air compressor. The most significant advantage this type of machine offers is in portability. The machine can be easily moved around to use it where it’s needed.
Plasma cutting machines with built-in compressors have two significant drawbacks, though. The first being they typically cost more than a standard machine. The second drawback is the strength of the machine. These types of plasma cutters are often underpowered and don’t perform nearly as well. If mobility is the thing you’re most concerned about, a plasma cutter with a built-in compressor is your best option. For the majority of welders and metal workers, however, the standard option is the way for you to go.
Pilot Arc Plasma Cutting
Pretty much every plasma cutting machine you come across will have what’s called a pilot arc. With a pilot arc, you’re able to cut your materials without touching the tip of the torch to the metal. When using this tool, you hold the torch just barely above the metal—less than half an inch. By using this method, you’re able to complete smoother cuts and make it easier to cut expanded metals.
If you’re using a machine without a pilot arc, you can still make great cuts; you just need to touch the tip of the torch to the materials you’re cutting.
If you’re trying to decide between purchasing a machine with or without a pilot arc, we recommend purchasing one with a pilot arc.
Here’s why:
While machines without pilot arcs are cheaper, they’ll cost you more in the long run. As you’ll learn below, plasma cutting machines have parts that wear out over time and need to be replaced. These are called consumables. Plasma cutting machines without a pilot arc require you to replace your consumables more often because they wear down faster when touching the torch to your materials. The money you save upfront by purchasing a machine without one will quickly be spent on consumables depending on how frequently you’re plasma cutting.
Plasma Cutting Consumables
As mentioned above, you’ll need to replace your consumables every so often as you use your plasma cutter. Some of the different torch consumables you’ll need to replace include:
- Shields
- Retaining caps
- Deflectors
- Nozzles
- Electrodes
- Swirl rings
Today, a lot of manufacturers sell consumable kits, which make it easy to replace everything at once. Depending on how often you use your plasma cutting machines, expect to replace your consumables roughly every 8 – 16 months.
To replace any of the consumables, all you need to do is disassemble the nozzle of your torch. Make sure the machine is turned off before attempting to replace anything or disassemble your torch.
Plasma Cutter Safety Equipment
A plasma cutting machine is a very helpful tool to use but it can cause serious injury. Before you use one of these machines, make sure that you have the proper safety equipment and are properly prepared.
As you would at any shop or job site, make sure that you’re wearing steel toe boots. Steel toe boots can save your feet from falling pieces of metal, sparks, and more. When you’re cutting materials, there will be sparks and molten metal being sprayed towards your feet and the floor. If you’re working in the heat, make sure you keep your boots tied up. It’s easy for a spark or piece of metal to shoot into one of your boots and burn your feet if you leave them untied.
A welding jacket, a thick pair of jeans, gloves, and a plasma helmet are also recommended. When you’re plasma cutting thicker pieces of metal, you can experience something called “blow back” from time to time. When you first start to cut a piece of metal (especially thicker pieces), there’s a chance that metal might spray upwards until the torch has cut all the way through. This is why it’s important to be wearing the right equipment and clothing. Blow back can easily lead to burns and holes in your clothing if you aren’t prepared. Nothing ruins a day on the job site more than a nasty burn from a scorching hot piece of metal!
To help make sure you avoid these potential hazards and injuries, here’s a list of recommended safety equipment when using a plasma cutting machine:
- Steel toe boots
- Plasma helmet
- Welding jacket
- Durable pair of jeans (no shorts or cut offs)
- Welding gloves
- Fire extinguisher
Additional Safety Considerations For Plasma Cutting
The first step to safe plasma cutting is having the right equipment. The next step is understanding what hazards you need to be aware of and prepared for.
First and foremost, a plasma helmet for eye protection is non-negotiable. Sure, you can get by with just a pair of goggles, but a mask protects your entire face from getting hit by metal sparks. If there is anyone in the shop watching you use the machine, make sure they’re wearing eye protection as well.
The next thing to consider is your work area and the different items around it. If your plasma cutter is next to a workbench, for instance, make sure to remove any chemicals from the area. Spare rags, brake cleaner, oil, and gas are all flammable materials that just need a spark from the metal you’re cutting to cause a lot of damage.
It goes without saying, but your materials are going to be very hot after you complete your cut. Even with gloves on, you can still burn your hands by touching a piece of metal right away. To help avoid this from happening, use a pair of vice grips or pliers to pick up any pieces and cool them off in a bath of water first.
Plasma cutters can cut through almost anything. Keep this in mind as you are setting up your pieces of metal. It’s best to secure them to the edge of your workbench with clamps and have them hang over the side. This way, you’ll avoid making any unwanted cuts into your workbench.
The final thing to consider is the area below your work space. Make sure that no sparks or falling pieces of metal go into your work boots or land on the plasma torch line.
Plasma Cutting Techniques
The most common technique to use with a plasma cutter is dragging. When you use this technique, you’ll slowly drag the torch across the piece of metal you’re cutting. One thing to keep in mind is that you don’t actually touch the tip of the torch to the metal. You can either hold it about ¼ inch above the metal or use a drag cup.
To begin your cut, start by holding the torch at a 45-degree angle. This will help reduce the chances of blow back shooting up into your helmet. Have the torch tilted slightly back towards you, and make sure you blow the sparks away from your body. If you hold the torch straight up, the sparks will go in every direction, which can lead to holes and burns.
When you’re cutting thicker metal, you’ll need to move slower so the torch is able to completely cut through your working piece. Once you’ve completed your cut, there may be some slag left over on either side. This can be easily removed with a hammer and chisel. If you’re cutting thicker pieces of metal, more slag may be produced. In this case, a grinder can be used to remove it quickly.
How To Use A Plasma Cutter Safely
Make sure to follow these steps to complete your plasma cutting operations safely:
- Open up some doors or windows in your shop to help ventilate air
- Prepare your workspace and make sure to remove any potential hazards
- Get your piece of metal safely secured to your workbench
- Use a wire brush to clean your cut area
- Draw a line to mark your cut
- Put on your safety equipment
- Turn on your air compressor and plasma cutter
- Make sure that you have enough line to move the torch the length of your cut
- Angle your torch at 45 degrees to prevent blow back
- Press the button on your torch to begin a smooth and safe cutting operation
- Continue the cut until it is complete
- Use a pair of vice grips to cool the piece of metal in a bath of water
- Prepare for your next cut or turn off the machine and air compressor
Improve Your Plasma Cutting Skills With Welder 101!
Learning to use a plasma cutting machine safely is a skill every welder needs to have. One way to develop this skill and learn to do it safely and properly is by enrolling in the Welder 101 course. This online training will help you learn how to complete plasma cutting operations with a library of resources to review.
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These easy-to-follow video tutorials will help you develop the skills you need to succeed as a welder. By enrolling in this course, you receive lifetime access to all past, current, and future content.
Welder 101 offers more than 50 tutorial videos to help you learn and get started. Whether you’re a weekend warrior looking to develop some new skills for a home project, or a budding apprentice looking to start your career in welding, this course will teach you everything you need to know about welding and how to do it safely.
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