Last Updated on June 28, 2021 by weldinghubs
MIG welding works for the protected and safe welding of any metal or alloy. The welding gun holds a nozzle from which a gas escapes out. The incoming gas protects the electric spark against environmental gases like oxygen, nitrogen, etc.
Moreover, the used gas helps in preventing the contamination of the welding process. It also prevents any deterioration in the quality of the welding process by blocking the path of environmental pollutants. So, the choice of the best MIG welding gas is very crucial for the whole process. But the decision is not that simple and straight away.
So, what gas is used for MIG welding? The use of gas in MIG welding helps provide an inert environment for the electric arc coming out of the wire electrode. Moreover, it shields the space between the metal pool and workspace. So, Helium and Argon being inert gases, are the best options for use in MIG welding.
Choosing the Right Shielding Gas
01. Carbon Dioxide (CO2):
Carbon dioxide gas is not inert because it can resist chemical reactions and reactivity to a small extent. The inertness of this gas is not of the level of Argon and Helium. The welder frequently uses this gas for the sake of MIG welding.
The main reason behinds its greater demand is its cost-effectiveness. It is many-fold times cheaper than argon gas. Moreover, you don’t need to use an inert gas with carbon dioxide. Its semi-inert nature makes it a perfect choice for welding.
If you want to weld the metals, particularly non-ferrous metals and steel, the pure form of argon makes sense. It is efficient in the production of a very stable and smooth electric arc. Moreover, the pure form of argon also protects the workspace from environmental contaminants.
There is no danger of any chemical reactivity by using this gas. The satisfied valency of argon makes it unreactive for any chemical species or any other contaminant. For the MiG welding of non-ferrous metals like titanium, aluminum, or magnesium, you can use the pure mixture of 100 % argon gas.
In any combination of welding gases, you can not increase the level of oxygen by more than nine percent. This level of oxygen is enough for creating a high-end arc, penetration, and fluidity.
Oxygen, being a reactive gas comparatively, is suitable for stainless steel or any low-grade alloy. However, the use of oxygen as a welding gas is not possible. You can not use it for the welding of aluminum, copper, magnesium, etc. is not possible.
The metal inert gas welding of non-ferrous metals like copper, titanium, aluminum, etc., is possible with the employment of pure helium gas. It brings the same benefits as that of helium. It has a plus point that you can also use it with stainless steel.
You can use this gas as a pure mixture or in the blend of any other inert gas like argon. The ratio of argon and helium can be 75 / 25 or 25 / 75. You can alternate between the values according to your needs and demands.
For different values of concentration, the outcomes will also change. There will be differences in the travel doped of the arc, beast profile, and penetration. Helium gas works for a better arc speed due to the hot arc current. So, you can achieve a better level of productivity with helium.
But the problem here is that it needs a better rate of flow. Moreover, you also need to make more or extra expenditures with this gas. The cost can increase many times. So, you can compare the procedure cost and the efficiency of the gas and decide according to the results.
The most demanding use of helium is in the tri-mix formula that is a blend of carbon dioxide, argon, and helium.
05. Other Gases:
Different gasses suitable for the MIG welding of steel or any other non-ferrous metal include oxygen, argon, helium, and carbon dioxide. The gases other than these four can be the mixture of any two or three gases from it.
What other gases are good for MIG welding mild steel?
Other gases useable for the MIG welding of mild steel include the mixture of helium, argon, and carbon dioxide in variable concentrations. The combination of these three gases helps in the fabrication of properties with customization and needs. You can also use C 25 mixture for this purpose.
Benefits of argon-carbon mix and carbon 100
The blend of argon and carbon dioxide is a highly recommendable mixture by the domestic and hobby welders. But the pure mix of these gases solely is also workable.
a) Argon-carbon mix for shielding:
If you are looking for a good arc quality, aesthetics, and finished welding look, argon is the top-notch gas for this purpose. It provides more tremendous advantages than pure argon or pure 100 % carbon dioxide mixture. Following are the key benefits of using a mixture of argon and carbon dioxide:
- Desirable puddle control.
- The desirable level of arc stability.
- Reduced spatter.
All these perks are enjoyable with a blend of 25 % carbon and 75 % argon. However, the percentage of argon can be up to 95 %, depending upon the size of wire and type or nature of metal. Similarly, you can also vary the ratio of carbon dioxide in the mixture according to needs and requirements.
This mixture of argon and carbon dioxide gas also assists in the spray transfer process. Greater productivity and efficiency are achievable with this process. Moreover, you can refine the look of your welds by using this combination. The narrow and shallow penetration of argon makes it a suitable gas for the welding of butts.
b) 100% carbon for shielding:
100% carbon dioxide is efficient and more productive because it does not need any additional inert gas for working. You can word your metals with it at a low cost because it cuts the price of any other gas.
Deep penetration at a meager cost is enjoyable with this gas. So, you can weld a thick or heavy metal with this gas. But there are some limitations to use this gas because you can operate welding with this gas for tiny circuits. Moreover, a less stable arc and great spatter are enjoyable with it.
What’s the Best Gas for MIG Welding Different Metals?
The ultimate solution for the MIG welding of different metals is the use of a C 25 mixture. This mixture contains 25 % carbon dioxide and 75 % argon as welding gases. The combination of inert gas with a semi-inert gas is responsible for providing deep penetration without causing any compromise to the quality of the welds or finished looks. This combination is best for all types of situations regardless of the sizes of the wires undergoing welding.
Moreover, this mixture is also cost-effective and workable for a maximum number of metals and alloys. You can use this combination for the MIG welding of non-ferrous metals and other alloys like mild steel. You can enjoy premium quality welding and top-notch looks with this mixture.
a) MIG Welding Gas for Carbon Steel Welding
Carbon dioxide gas is the most useable gas for performing the MIG welding of carbon steel. A very well-known mixture for the welding of Carbon Steel is C25. It is a mixture of about 75 % Argon that is an inert gas. The remaining 25 percent of the solution comprises Carbon dioxide.
This blend of carbon dioxide and argon or solely carbon dioxide provides the maximum level of penetration. It also produces enough smoke and the roughest form of welding. Some other mixtures are also in use for carbon steel welding. However, another useable mixture is the use of carbon dioxide, argon, and oxygen.
b) MIG Welding Gas for Stainless Steel Welding:
Almost all types of MIG welding proceed with the usage of a mixture of carbon dioxide and argon. The percentage of these gases can be different in different kinds of blends. However, the hybrid of 98 % argon and 2 % carbon dioxide is suitable for the MIG welding of steel. The welding stores and chains call this mixture with the name of C 2.
However, in different situations, we can also use a mixture of two inert gases, helium and argon, and a third gas, Carbon dioxide. The percentage of helium, argon, and carbon dioxide in the tri mixture can be 90 %, 7.5 %, and 2.5 %, respectively.
But, the different welding stores of stainless steel make their mixtures of welding gases. Different percentages of the welding gases tailor the quality of welding in different ways. The easiness of welding is variable with combinations of various gases.
c) MIG Welding Gas for Aluminum Welding
MIG Aluminum welding goes smooth with the use of a single gas that is argon. Argon is an inert gas that provides maximum penetration and good quality welding. However, there exist some exceptions regarding the use of argon for the welding of aluminum. Variations in the usage of 100 % mixture of welding gases can occur. It is must be due to differences in the size of aluminum wire to be weld.
If the thickness of the aluminum wire you want to weld exceeds the limit of half an inch, the solely used argon gas does not bring efficiency in the welding process. In such cases, the helium gas is also useable in the mixture of argon in different proportions.
The sole use of argon, the inert gas, is possible and suitable for the metals like:
- Alloys of nickel.
- Alloys of copper.
The Cost of the Gas
Different gases are useable for metal inert gas welding. You can also mix the gases to achieve your desired qualities and properties. So, the cost of the welding gases also varies according to the combinations used. A full container of an inert gas mixture for performing MIG welding can cost about $150 to $300.
For example, the most useable welding gas or shielding gas mixture that is C25 causes an expense of 150 to 170 dollars. However, carbon dioxide cut a lot of costs as this is a very cheap gas. So, you can employ the use of carbon dioxide for welding thicker metals due to its cost-efficiency.
The final verdict is that different combinations are available for the welding of non-ferrous metals and alloys. You can make alterations in the proportion of gases in a mixture according to your needs.
Although the usage of argon for welding is the best option for all circumstances, the mixing of a semi-inert gas like Carbon dioxide in it can prevent the deterioration in the aesthetics of the finished weld. So, you can make use of the C25 mixture for any wire size or any metal. Moreover, you can also mix two inert gases with oxygen for deep penetration.
Will the same gas work for both MIG and TIG welding?
You cannot use the same gas for Metal Inert Gas welding and Tungsten Arc Gas welding. Because, in TIG welding, the inert system does no compromises the look or aesthetics of welding. But in MIG welding, the solely used inert gas deteriorates the aesthetics of the final weld.
What gas is best for MIG welding?
The answer to this question is not so simple. Both 100% Carbon dioxide mixture and C 25 mixture, containing 25% carbon dioxide and 75% argon, are preferable for usage in MIG welding. Both these combinations are suitable for Mild steel, and both home and hobby MIG welders use these combinations.
Can I use argon for MIG welding mild steel?
Yes, it is okay to use 100% Argon for the MIG welding of mild steel. But there are perks and drawbacks to using it. Argon is one of the four different welding combinations used for MIG welding. But it is better to use it with gas in proportion.