With an increase in the demand for welding services, there is always a need to buy new tools to carry welding and other related services. The most common welding tools, such as gas-arc or gas-tungsten arc welding machine, requires compressed air to power the electrode.
Compressed air is very expensive. Therefore, an alternative to compressed air for welding is the use of compressed carbon dioxide. However, it is very important to be aware that using CO2 for tig welding does not provide the same quality as compared to that of compressed air.
In this guide, I have outlined the advantages and disadvantages of using CO2 for tig welding so that you will make informed decisions when purchasing welding equipment.
How Much Amount Does TIG Welder Use for CO2?
Carbon Dioxide is used in welding, soldering, and brazing applications to lower the temperature of metal parts during operations. CO2 is available for welding and brazing in the US in tanks ranging from 1-12 lbs. Most larger manufacturers also supply tanks ranging from 30lbs. and up. Some are specifically designed for tig welding, while others are intended for use with oxyacetylene.
A tig welder uses a small amount of carbon dioxide gas to produce a spark for arc starting and to keep the arc stable. Carbon dioxide is not suitable for direct arc welding as it reacts with oxygen to form oxides. Welding done with CO2 requires a minimum amount of oxygen available in the area, and proper ventilation is essential.
When working with CO2, you have a choice of tanks available for welding; 1lb, 2 lbs, 4 lbs, 8 lbs, or 12 lbs. In most instances, 2 lb. tanks are sufficient for tig welding as they are easy to handle and provide a good yield rate.
So, if you are using 2 lbs. tanks, the CO2 gas should be mixed with 50% air and 50% CO2. The ratio of air and this gas can vary depending on the size of the tank and the workpiece.
Smaller items can weld in CO2 with about a 1/3 air/CO2 mixture, and larger pieces require more air. It is recommended that the gas is replaced several times during welding to maintain optimum welding conditions.
What is the Purpose of Shielding Gas in TIG Welding?
Shielding gas is used in TIG welding to protect the molten metal from oxidation during welding.
This welding is performed with an alternating current of about 1,500 to 2,000 watts. A copper electrode is heated above the melting point of aluminum, with the tungsten electrode being the negative pole. Shielding gas is introduced between the electrodes.
When welding aluminum or aluminum alloys, a gas such as argon or helium is used as the shielding gas. Argon does not oxidize the metal, whereas helium does. For welding steels, the shielding gas usually consists of a mixture of about 8% carbon dioxide (CO2), 0.25% nitrogen (N2), and 90.75% argon (Ar) with a small amount of CO2.
The gases are mixed at the surface of the electrode and flow to the weld joint, where they protect the molten metal from oxidation. If the weld zone is covered with fluxes or powder material, the inert gas may replace the shield gas.
TIG welding is useful when there is a large amount of melting, and heat must concentrate on the weld zone. The shielding gas prevents heat loss to surrounding areas and protects the molten metal from being oxidized. TIG welding is ideal for welding aluminum, stainless steel, and many other metals.
Variety of Metals for TIG Welding
Various metals may be welded, including steel, aluminum, cast iron, copper, brass, bronze, nickel, titanium, stainless steel, zinc, etc. The electrodes may be either tungsten or carbon electrodes.
TIG welding of aluminum and other metals can be done on mild steel substrates, but the welding should be done on aluminum-clad steel or stainless steel. TIG welding must be done under a vacuum or an inert atmosphere.
Shielded TIG welding welds aluminum and aluminum alloys, but there are some limitations. Welding of thick plates with TIG requires high voltage and a small spot size. Therefore, it must do with a relatively low current to reduce distortion and prevent spatter formation. High currents cause overheating and distort the plate.
The high current causes arcing, which reduces the efficiency of the process and produces a spatter. As with all welding processes, shielded TIG welding is unsuitable for welding soft metals, and some metals, such as magnesium, cannot be welded by shielded TIG.
Which Gas is used for TIG as Shielding Gas?
TIG is a solid-state welding process that typically involves direct current electricity (amperage) to melt metal into another piece, usually with filler wire. Welding occurs with a very fine tungsten electrode and a small shielding gas (which protects the weld from airborne particles).
We use argon, helium, and sometimes hydrogen as the shielding gas, which is selected according to the different properties of the welding workpiece. We select argon for the aluminum material, helium for the mild steel, and hydrogen for the copper and nickel.
In addition, the gas for TIG welding should be able to mix with air because when we weld underwater, argon cannot mix with the water, causing the arc not to start, and the weld quality will decrease. Therefore, argon is not suitable for underwater welding.
Why is Argon Used as a Shielding Gas in TIG Welding?
We’ve seen many welding videos showing argon gas as a shielding gas in tig welding processes, and the majority of them are for the metal fabrication industry.
One of the most common misconceptions about argon gas is that it doesn’t protect you from burns during tig welding. On the contrary, when it’s used correctly in tig welding, you will be fully protected from being burned, and your welds will also be more reliable.
How does Argon Work?
Argon is an inert gas. Its high electrical neutrality is also known as a noble gas. That means that argon is highly resistant to absorbing electric charges from the tungsten electrode.
So that means that argon is an excellent choice of gas to be used in tig welding because the arc between the tungsten and the steel won’t be able to transfer electrical charges to the argon. This protects your workpiece from burning, so you can work with very little argon in tig welding.
Benefits of Using Argon in TIG Welding
Here are some of the benefits of using argon in tig welding:
- It’s a cost-effective and easily accessible shielding gas.
- In fact, Argon is the second most common shielding gas in the world after helium, according to a report from the U.S. Department of Labor. It’s cheap and safe to use.
- It provides good arc stability and prevents arc blowout.
- Argon is an excellent alternative to air, and it’s less prone to blowing the arc than oxygen, which makes it great for preventing arc blowout.
- It won’t burn your skin.
- Since argon is an inert gas, it won’t be able to absorb the electric charge from the tungsten electrode, which means that you won’t be at risk of getting burned.
Overall, there are several reasons why argon is an ideal shielding gas for tig welding. It’s inexpensive, it’s readily available, it’s non-toxic, and it doesn’t interfere with the arc.
Can CO2 be Used as a Shielding Gas?
We’ve got some great feedback about shielding gases, but this one caught our eye. This isn’t something you would necessarily know about, but the folks at CO2 Solutions have been studying it for years. They’ve worked with many other industries to protect their equipment and people, including pharmaceuticals, electronics, aerospace, and even military applications.
So what does CO2 Solutions think about it? Well, they’ve put together nice instructions that explain how they use CO2 to keep things running smoothly. We’re not sure how applicable this might be for solar pool heaters, but it’s still a neat little explanation. Check it out!
The first thing we’ll say is that this video does an awesome job explaining how CO2 is a shielding gas. It also shows many examples of how people use this kind of shielding and how effective it can be.
Of course, there are a few drawbacks to shielding gases. For starters, they cost money, and the bigger the container you need, the more expensive it will be.
- They’re also not very portable and take up a fair bit of space. So they won’t work on smaller projects.
- They also won’t help you with your heating system and won’t eliminate odors as a carbon filter would.
- That being said, they provide protection for sensitive items more prone to environmental damage.
Can you Weld Steel with CO2?
If you want to save money and reduce environmental impact, try using carbon dioxide instead of conventional welding.
With CO2, you no longer need any filler rods, gas, or shielding gas. It’s also 100% clean and emits zero smoke, so you can enjoy it all day without worrying about bad smells. You can weld anything, including steel, aluminum, plastic, wood, and concrete. And with a range of sizes and output power available, you can easily cover large areas and big objects.
The downside is that CO2 is expensive, but it’s worth investing in. The welding can be done without melting the workpiece – no fumes, so no air quality issues. If you want to save money, it’s a great way to do it.
But even though CO2 is less expensive than other welding methods, it still requires a high skill level. It’s easy to cause the flame to get out of control, so be careful. You can use a welding gun, but a good, quality welding mask and welding goggles are needed to reduce the risk of burns and sparks.
Can you Weld Steel with CO2?
CO2 welding is the most commonly used process for fabricating metal components, especially stainless steel welding. The process is clean and produces little to no waste, meaning it can be performed on a wide range of materials with minimal restrictions.
In addition, CO2 welding is widely available and affordable. CO2 is commonly used for general welding, spot welding, pipe welding, and metal fabrication.
Welding with CO2 is safe and is a clean process that can be done indoors, even in small spaces.
I strongly believe in TIG welding with a CO2 shield and electrode. I was initially skeptical of the claims that welding with CO2 would cause a chemical burn or even corrosion on metals because of the nature of the process.
But after experimenting with my equipment, I found a combination of factors conducive to the success of TIG welding with CO2. I recommend that anyone serious about welding take a closer look at the possibilities of welding with CO2.