Welding is a specialised skill that can take decades to master. Ensuring you understand all the elements in the process is essential to developing your skills more promptly. As leading experts in bottle gas, today we’ll cover the role of blended gases, what they are and why they’re important for achieving the best outcome from your welding.
The Role of Gases in Welding
Gases are indispensable for welding, serving two core purposes: shielding and fuel supply. They protect the weld pool against atmospheric contamination, securing the integrity of the weld. Shielding gases, including argon, carbon dioxide, and helium, surround the weld pool during the welding process. However, fuel gases such as acetylene, propane, and butane gas provide essential thermal energy for welding and cutting. Oxygen is also utilised with fuel gases and occasionally in shielding mixtures.
Whilst some gasses are used alone within the welding process, such as our argon welding gas, others, such as our CO2 argon mix, combine two gases to get the optimum product for the right process and material.
What Are Compound Gases?
If pure gases aren’t right for your applications, you can mix them to help with splatter reduction or deeper penetrations to create compound gases. These are combinations of gases like argon and carbon dioxide or argon and oxygen. Mixed gases often make the welding process smoother, with fewer troublesome splatters. They can also be used with a wider variety of materials.
You can adjust the mix of the gases depending on what you are welding. However, there are some drawbacks to using mixed gases. They can be more expensive, and they may require more safety measures to handle properly because they are mixtures. So, choosing between pure or mixed gases for welding often depends on your specific needs, factoring in the nature of your job, your budget, and safety considerations.
The Most Common Gas Mixtures in Welding
Gas mixtures in welding are tailored to the specific process and materials involved. Arguably, the most frequently used gas blend is 75% Argon and 25% Carbon Dioxide (C25), typical in MIG welding for its superior arc stability, minimal spatter, and great bead appearance. Another common blend comprises 90-99% Argon and 1-10% Oxygen, favoured in MIG and TIG welding, principally for stainless steel, given its hard-to-match arc stability and smooth weld pool surface.
Pure Carbon Dioxide, while generating more spatter, is often employed in MIG and Flux Cored Arc Welding processes, particularly when working with carbon steel. It’s important to remember that the welding task, the metal in use, and the required properties of the weld determine the use of these gases. Gases like helium may also be introduced to enhance weld quality and penetration.
Limitations of Using Singular Gases versus Compound Gases in Welding
When welding, using one type of gas, like our argon gas cylinders or pure carbon dioxide, can be limiting. This is because these gases aren’t compatible with all materials or welding methods. Let’s take argon as an example. It’s most commonly used in the TIG welding method and works well with materials like stainless steel.
However, it can cause issues when used with other materials. When inappropriately used with certain materials, argon can create safety hazards, including asphyxiation risks and violent reactions to water. It can also result in poor-quality welds if materials fail to react to argon as required during welding procedures. The same issues may appear with pure carbon dioxide – while it’s a more affordable option, it can be problematic, causing a more unstable arc and more little splatters of molten material.
Considerations When Using a Gas Blend in Welding
When using a blend of gases in welding, there are quite a few factors that you need to consider.
1. Compatibility
Remember that the chosen gas blend should be compatible with the welding process and the type of metal to be welded. For instance, a mixture of Argon and Carbon Dioxide is commonly used in MIG welding, but this combination might not work well for other types of welding, resulting in poor welds if the argon fails to react well with the metal.
2. Operational Capability
Consider the operational aspects, including arc characteristics, penetration, and weld quality. Different gas combinations may affect the stability of the welding arc, the depth of penetration into the base material, and the overall appearance and quality of the weld.
3. Safety and Cost Aspects
Safety and cost must be taken into account. Some gas blends may require specific precautions to handle and store them safely. Also, while certain blends may provide a higher quality weld, they could also be more expensive, so making sure that you find a blend that suits your applications whilst being cost-effective in the long run is essential.
The Importance of Getting the Right Gas
Each gas blend is specifically tested for a particular welding process and material type. Certain procedures, like atomic hydrogen welding, also necessitate specialised gases, including hydrogen. Selecting the appropriate gas blend is paramount for welding excellence and meeting demands across various sectors.
If you’re beginning your welding journey as a hobby or are unsure of the exact type of gas you need, we can help. Whether you need a blended gas, a pure gas or something more specific, give us a call, and we will advise you on the correct MIG welding gas or TIG welding gases for your applications.
