As a key ingredient in welding, argon gas is a valuable tool that allows welders to fuse durable welds.
What is Argon?
Argon is an odorless, colorless, and tasteless gas that makes up 0.93% of the Earth’s atmosphere.
Chemically speaking, argon is a noble gas with the element symbol Ar and an atomic number of 18.
Noble gases are considered stable and have low reaction rates. Derived from the Greek word Argos, meaning “lazy” or “inactive”, it does not combine with other elements.
Its laziness makes argon gas uniquely capable of providing the ideal inert atmosphere needed for incandescent and fluorescent light bulbs, semiconductor crystals, and welding.
Is Argon Flammable?
Argon is non-flammable and does not support combustion. With the welding process sometimes reaching 7000 degrees Fahrenheit (ca. 3,871 °C), it is a safe option for welders.
Is Argon Poisonous?
In addition to being nonflammable, argon is also non toxic. However, there are health hazards when using argon.
Argon is classified as a simple asphyxiant. Simply put, using argon decreases oxygen content in the air. This might be great for arc welding, but it’s not so great for oxygen-dependent welders.
When Argon is used for welding, a well-ventilated work area is recommended.
Does Argon React With Other Gases?
Argon is a noble gas and does not react with other gases.
Other members of the noble gas group include helium, neon, xenon, radon, and krypton. This exclusive group is also known as “inert gases” because they do not easily react with other elements or compounds. In fact, the definition of the word inert is “chemically inactive.”
If we’re splitting chemical hairs, it is possible for argon gas to react with other elements. However, it would take extreme measures to induce a reaction. It took an entire Finnish team of theoretical chemists in 1962 to force argon to react with another element.
What Is Shielding Gas?
Shielding gases are inert gases used in the welding process to shield a weld from other elements found in the atmosphere. Elements such as oxygen, carbon dioxide, nitrogen, or water vapor can contaminate the weld. This can lead to oxidation, corrosion, or general weakening of the weld.
Diagram from https://www.sciencedirect.com/topics/engineering/gas-metal-arc-welding
Shielding gases have been used in the field of welding since the 1920s. They became standard practice during World War II when the aircraft industry looked for a way to improve the construction of planes.
Argon is an ideal shielding gas to use when working with aluminum and nonferrous metals. Helium is another commonly used shielding gas that works best when welding magnesium, copper, and aluminum metals.
Why do Welders Use Argon Gas?
Argon is used for welding due to its low cost, shielding gas capabilities, and stability.
In addition to not reacting with other elements, it doesn’t burst into flames when exposed to the extreme temperatures involved in welding.
Its natural abundance in the Earth’s atmosphere also makes it an affordable gas option for welders.
A welding engineer will enjoy the benefits of an effective shielding gas. These types of gases displace other elements in the atmosphere, protect the integrity of their welds, and provide arc stability.
Using an Argon Regulator
Regulators are used in welding to control the flow rate of gas from the tank to the welding hose.
Regulating the flow of gas provides a higher quality weld, a safer work environment, and produces less waste. Connecting a hose directly to a gas tank instead of a regulator would cause an uncontrollable flow of gas. This would blow out the welding arc and waste all the gas in the tank.
It is imperative to use a regulator specifically designed for argon gas. These regulators have two gauges. One to determine the pressure of the gas tank and the other to measure the gas flow rate from the tank to the hose.
These argon regulators can be used to manage argon gas flow rate and pressure:
This SPARC argon flow meter and regulator is ideal for welders
This dual output argon regulator and flow meter is a high quality option from SPARC
Managing Argon Welding Flow Rate
Welders use regulators to manage the flow rate of gas from pressurized tanks to their welding hose.
Gas tank pressure is measured in PSI, or pounds per square inch. Flow rate, however, is measure by CFH, or cubic feet of gas per hour.
Flow rates when using argon will vary depending on the welder, the method of welding, and the welding job at hand. Industry-standard flow rates typically range between 10cfh and 35cfh.
How Long do Argon Welding Tanks Last?
Determining how long an argon welding tank will last depends on a variety of factors. Tank size, flow rate, and frequency of use should be considered to best estimate how many hours a tank of argon will provide.
Welding tanks are available in several sizes ranging from 20 cubic feet (0.57 m³) to 330 cubic feet (ca. 9 m³).
One way to achieve a rough estimate of how long a tank will last is to use the following equation:
Dividing cylinder volume by flow rate helps determine how long a tank will last
MIG and TIG Welding
The most common types of welding methods are MIG welding and TIG welding.
Both use shielding gases to protect the integrity of the weld. Both methods can be used on a variety of metals such as aluminum, carbon steel, and stainless steel.
These two welding techniques use extreme heat generated by an electrical current to melt metal to form a solid joint. While both are effective welding methods used throughout an array of industries, they have distinct differences.
MIG stands for Metal Inert Gas. In the MIG welding process, a consumable wire rod is fed through the handle of the torch. This creates a welding arc between the rod and base metal. A trigger is used for the welder to control the feeding of the consumable rod.
Diagram from https://www.technoxmachine.com/blog/mig-vs-tig-welding/
MIG welding melts a metal rod along with the base metal to allow the welder to create a solid metal joint. The metal rod is fed through the gun similar to how a glue stick is melted with a glue gun.
This technique is usually used when larger or thicker metals are involved. It is both an easy technique to learn and a faster technique to execute. While it’s quicker, it may produce a less aesthetic weld bead and is less sturdy than other welding processes.
Tungsten Inert Gas is commonly known as TIG welding. It is a method that uses a non-consumable tungsten electrode instead of melting a wire rod. This creates a welding arc between the tungsten electrode, a hand-held filler rod, and the base metal. It can also be used without a filler, in which case, the welding arc occurs between just the tungsten electrode and the base metal.
This method works best when welding aluminum and other small or thin metals. Carbon steel and stainless steel are also common TIG welding materials.
A more complicated process than MIG welding, TIG welding requires special training for welders to produce clean and precise welds. This method is a slower process than MIG welding, but it allows for greater control and a cleaner weld bead.
The Pros and Cons of MIG and TIG Welding
Both MIG and TIG welding methods have advantages and disadvantages. Understanding these pros and cons can help welders choose the best method for a job.
MIG welding is easier and faster resulting in fewer production costs. However, it offers less precise and weaker welds and runs a higher risk of having visually unappealing spatter.
Alternatively, TIG welding produces cleaner, stronger welds. The drawbacks are the amount of time it takes to both learn and perform proper welds, as well as higher production costs.
Welding with Different Types of Argon Gas
Different types of welding jobs call for different types of argon gas mixtures to achieve the best results. Here are a few types of argon mixtures commonly used for shield welding:
100% argon (technically 99.99%) is used when welding non-ferrous metals such as aluminum, copper, and nickle. Pure argon is also the number one choice for TIG welding. Not only does pure argon protect the weld from contamination, it also protects the tungsten electrode from forming tungsten oxides.
Argon-Carbon Dioxide Mixtures
The most common type of gases used in shield welding is argon and CO2 mixes. These mixes are made up of anywhere between 80-95% argon and 5-20% CO2.
The level of CO2 is increased depending on welding material thickness to improve weld penetration. Increasing the CO2 content in the gas mixture will also increase the chance of spatter.
These mixes are most often used for carbon, low alloys, and some stainless steels.
Another common type of mixture is argon and oxygen. These blends range from 95-99% argon to 1-5% oxygen.
Argon-oxygen mixtures are used for carbon and stainless steel metals to provide a stable welding arc and low levels of spatter.
Argon-Helium-Carbon Dioxide Mixtures
Tri-mix gas blends are available in a wide range of mixes including:
- 90% helium, 7.5% argon, and 2.5% CO2
- 66% argon, 26.5% helium, and 7.5% CO2
- 66.1% argon, 33% helium, and 0.9% CO2
These blends are used for welding stainless steel, carbon, and low-alloy steel.
The Dangers of Argon
Argon is a relatively safe gas to use in the welding process because it is non-flammable and nontoxic. Although safer than most, argon does pose safety hazards if certain precautions are not taken.
The biggest risk when working with argon is asphyxiation. Because argon displaces oxygen, it can lead to suffocation if not used in an area with plenty of ventilation.
Without proper ventilation, argon can cause:
- Rapid breathing
- Stinging of the nose and throat
If excessive inhalation of argon occurs, it is important to move to an area with fresh air as quickly as possible. Oxygen should be administered if there is difficulty breathing. If an individual is not breathing, move them into the fresh air and administer artificial respiration methods (such as CPR). Emergency medical help should also be called.
Argon is a stable, nonflammable, and nontoxic gas. It is an ideal shield welding gas because it disperses contaminating elements in the atmosphere and protects welds from oxidation and corrosion.
Argon as a shielding gas produces cleaner and stronger welds. Welders use regulators and flow meters to control the flow of the argon from the gas tank to the welding torch.
You can find high-quality SPARC welding equipment here. We offer an outstanding 1 to 2 year USA warranty on most of our welding supplies.