A plasma cutter is a device that uses gas to create an electrical arc that is used to cut through all kinds of metals in metalworks. The unit makes it super easy and fast to cut metals with very little slag. As the popularity of the device soars, we keep getting more and more questions about it.
We write articles to answer the questions. Before this article, we had written two different articles to answer two different sets of questions. Similarly, this article is meant to answer the question – how much air does a plasma cutter need? We have answered the question in detail.
In addition, we have also answered some other frequently asked questions in this article as well. Let’s quickly dive into the real issues now.
How Much Air Does A Plasma Cutter Need?
The amount of air required by a plasma cutter depends on the amperage of the plasma cutter. Generally, low amperage cuts require lower air pressure. We tried several models of air pressure and they all used about 45 – 70 psi air pressure. So, we can say that the minimum air pressure required by a plasma cutter is 45 psi and the maximum is 70 psi.
What Kind Of Air Does A Plasma Cutter Use?
The plasma cutter uses air, hydrogen, oxygen, nitrogen, and argon to cut through sheets of metal. When the metal is thin, it can make use of only one of the 5 gas types. We mean when the thickness of the metal is half an inch or less, each of the 5 gas types can get the job done.
Conversely, when the sheet is relatively thicker, it will require the combination of the gas types for smoother and cleaner cuts. The type of air used by a plasma cutter is actually compressed air. Compressed air is versatile and it is inexpensive. Compressed air works for cutting aluminum, stainless steel, mild steel, and most type of metals.
You can use compressed air as the main gas or as a support. Another advantage of compressed air is that it does not leave any particles behind when used to cut through metal sheets.
Why Do Plasma Cutters Use Air?
Plasma cutters make use of air pressure in two stages of the cutting process. The arc will first heat up the part of the metal to be cut off until it is semi-gaseous. At the second stage, the plasma is forced by blasts of air to finish the cut.
More importantly, all plasma cutters need compressed air to generate enough air pressure to cut through metal sheets.
Does A Plasma Cutter Need Compressed Air?
Yes, all plasma cutters need compressed air to cut through metals. However, if the metal sheet being cut is thin, plasma cutters can use any of hydrogen, oxygen, nitrogen, and argon instead of compressed air. All of these 5 gas types have their pros and cons. Let’s quickly discuss them.
Argon-Hydrogen – When this combination is used, it will produce the hottest plasma for cutting through metals, and the combination can be used for plasma gouging on any material. This combination has a couple of shortcomings too. The two gases are very expensive. It may not be a good idea to use them for casual metal fabrication. Also, when you use a mixture of argon and hydrogen, there are chances that the dross levels may occur along the bottom edge of the metals being cut.
Nitrogen – This gas produces an excellent cut quality. Nitrogen is also an expensive gas.
Oxygen – This gas has the fastest cutting speed and it produces the highest cut quality on mild steel. However, it also has some downsides. Oxygen is very expensive and it can be used up very quickly.
Compressed air – The major advantage of compressed air is that it is economical and it can be used for gouging too. The disadvantage of compressed air is that it leaves an oxidized cut area. In addition, it may require a separate air compressor unit.
Can You Use A Plasma Cutter Without Air?
Please don’t ever try this. Yes, your plasma cutter will work without air, but it will burn the metal horribly. It won’t cut through it. This is because the flame will burst out like an uncontrolled fire. In addition, it will also burn the mouth of your torch.
After using your plasma without air, the torch will be so scalded that you won’t be able to use it again. You’ll have to get another one. So, the plain and simple answer to this question is a big NO! Don’t try an experiment that will destroy your gear.
Do You Need Oxygen For A Plasma Cutter?
Yes, all plasma cutters can use oxygen for cutting all kinds of metals. In fact, oxygen has the fastest cutting speed. And it is the best gas for cutting through mild steel. However, oxygen is very expensive, and it gets exhausted fast. That’s why compressed air is a better and more cost-effective alternative.
What Quality Should I Look For In I Plasma Cutter?
If you want to buy a plasma cutter for your professional use, you need to go for a 30-amp plasma cutter. That should be able to handle all kinds of cuts. And such cutters will work on 240V. On the other hand, if you’re just a hobbyist that wants to catch some fun with some metalworks, a 15-amp plasma cutter should be okay for you.
Are you going to be carrying the plasma cutter around from one job site to the other? You may need to consider portability. If you go for a heavy-duty machine, you may not be able to carry it around easily. As a professional metal fabricator, it might be a good idea to have both. While in your shop, you can work with the big one and when you have out-of-shop jobs, you can go with a portable plasma cutter.
Final Thoughts
As a reminder, plasma cutters need about 45 – 70 psi air pressure to run smoothly. Also, the 5 types of gas that are used by plasma cutters are oxygen, nitrogen, argon, hydrogen, and compressed air. Most importantly, never use your plasma cutter without air. Your gear will be fried literarily.
