MIG vs TIG Welding: What Method is Better to Use?

Whether you are doing repairs in your home, renovating, redecorating it, or you are simply doing a DIY project, working with metals requires good welding skills. These skills can only be acquired with practice and knowledge of different welding methods. 

There are several types of welding used all over the world, with arc welding being by far the most common. Deciding whether to use MIG or TIG welding can result in either a structurally sound construction or a failed project. In this article, I will lay out all the details about the basics of arc welding and do a MIG vs TIG welding comparison as well.

The Difference: MIG vs TIG Welding

MIG and TIG welding are both types of arc welding that use inert gas. Arc welding is the process of welding metals using heat generated by electricity. It is achieved by causing two oppositely charged metals or metals with a high potential difference to come into contact, creating massive amounts of heat as arcing occurs. So, what is the difference between MIG and TIG welding?

What Is MIG Welding?

MIG welding stands for metal inert gas, but what is MIG welding exactly? It is the use of a solid metal wire electrode fed into a weld pool using a welding gun. Unlike some forms of welding, metal inert gas one does not have any special additive chemicals that counter the effects of oil or rust on metals, and instead, the surface has to be cleaned first. As you weld, the gas is used as a shielding substance to keep the surfaces you are welding free from contamination.

MIG welding is by far the most popular among enthusiasts, people who are new to this activity. It is due to the shorter period it takes to learn the basics and get to welding itself. In a nutshell, here are the considerations before utilizing MIG welding.

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Safety

Before engaging in any type of welding activities, you should ensure you have all the necessary safety gear. In this case, you will need leather gloves, a flame-resistant coat, pants., safety glasses to protect your eyes from the bright sparks and the splatter, and a helmet for your head. Also, make sure to secure any loose clothing or hair.

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Metal Preparation

Because you do not get any chemical additives on your electrodes, you have to deal with rusty or oily surfaces before you can do any welding. Use a metal brush or any other cleaning equipment to adequately clean the metal piece you intend to weld to ascertain you get the best weld stability.

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Wire Selection

I advise you to select the wire relative to the thickness of the metal or metals you intend to weld together. Use thinner wires for thin materials and thicker wire diameters for larger surfaces that may require deeper penetration for a stable weld. The wire sticking out from your electron gun should not be too long. I advise you to use it just under half an inch long.

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Equipment

mig welding process

Ensure you have the right equipment with all the connections secure and not moving and make sure to check the wire tension and set the electrode polarity. In MIG welding, a positive DC electrode is used. I advise you to stick to this feature.

The gas flow is optimal at about twenty to twenty-five-cubic feet per hour. As part of the safety precautions, check for any gas leaks in your pipes, as it may eventually affect the quality of welds you get.

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Gas Levels

The next step in MIG welding is determining the mix of gas that you want to use. It directly influences the depth of penetration of your welds. In general application, a 75/25 argon to carbon dioxide mix is the best option. It offers sufficient penetration for conventional welds and does not cause too much splatter. It also makes for really good-looking welds.

If you are working with especially thick materials that need more deep welds, a 100 percent carbon dioxide selection will serve you for sure. The downside of it is rough-looking welds with too much splatter. When you are welding and start noticing inconsistent splatter and large beads forming even with consistent travel speed, check for gas leaks and adjust gas levels.

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Welding Angles

The two important angles when welding are work and travel ones. The work angle is the way you hold the gun according to how the joint you are welding is aligned. The travel one is the angle of the welding gun relative to its position if it were held perpendicularly. The best work angle may vary, depending on the splatter you can tolerate, as, for less substance, you need smaller travel angles.

When you are welding on vertical, horizontal, or upside-down platforms, vary your travel speed and welding angles appropriately to get the result you need. I can’t recommend a universal solution, as the conditions for different welds vary in many areas, including the type of metal, joint, butt, T-joint, or spot welding.

The last variable for MIG welding is the voltage and ampere for use. Check your welding machine for specifications, as most brands offer a chart showing different preferences. Always ensure your workpiece is properly clamped with the ground from the welding machine.

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Pros of MIG Welding

  • Easy to learn;
  • You can manage the process with one hand;
  • Good for all metal thicknesses;
  • Varying gas levels allow different weld depths.
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Cons

  • May causes temperature shock on metals;
  • May create brittle joints in some materials.
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What Is TIG Welding?

tig welding process

This method stands for Tungsten Inert Gas welding. In detail, what is TIG welding? It is a type of arc welding that utilizes a consumable tungsten rod and a filler wire to weld using electrically generated heat. It is very similar to oxyacetylene welding, and the only difference is that this approach uses an electric torch instead of an actual flame. The inert gas, usually argon, is used to clear contaminants and cool the weld pool after the work is done.

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Safety

TIG welding has similar safety precautions to the MIG method. The level of penetration is slightly different, with TIG only varying the shape of the tip of the tungsten rod to achieve different penetration. There are various parts of a TIG kit, and the tungsten rod is the point through which the electric head is channeled. The tip is covered partially with a ceramic hood for safety.

Some TIG rigs have a pedal for soft start and stop, whereas, in other applications, you may require a finger remote for easy control. When working on a bench, use the foot pedal and the finger remote for more comfortable welding positions.

The benefits of the soft start and stop are best realized for metal joints with stability issues caused by a temperature shock. It includes welds on moving parts of cars, bicycles, or machinery.

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Wire Selection

The choice of filler wire material to be used depends on the surface you are welding. Different alloys form stronger joints with others, so your filler should be appropriate for the metals you are working with. The most common type is the 4043 alloy. Check the filler charts to see which one is recommended for the material you are using.

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Gas

The gas should not be the same as that used in MIG welding, and it is because TIG welding works differently. It doesn’t depend on the gas. Penetration is managed by the tip you use, the amperage, and the alloy.

TIG welding specifies different polarities of electricity from the welder for different metals. For example, steel uses DC, whereas Aluminum utilizes AC. When you have the material and the required filler wire, set it up on a metal top table or securely clamp the working wire/ground wire to the metal and then bring the tungsten electric torch to the starting point. Using your other hand, feed in the filler wire.

To start the welding, step on the paddle and release it. When you hear the gas release, bring the filler and tungsten rod into contact at the desired joint and weld. Change your travel speed, depending on the desired results.

The key difference between TIG and MIG include:

  • The use of a filler wire fed separately from the welding gun and use of a tungsten rod;
  • The ability to weld without temperature shock on the metal in TIG welding;
  • The use of a foot paddle or remote control for TIG welding;
  • TIG can use both AC or DC, whereas MIG uses a positive DC electrode or of the opposite polarity.
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Pros of TIG Welding

  • No temperature shock on metals;
  • Varying fillers for more appropriate welds on different metal surfaces;
  • More control over the weld undercuts and splatter prevention;
  • The precision is higher.
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Cons

  • Requires attention to the type of filler depending on the material;
  • A mistake would be costly.

Arc Welding: TIG vs. MIG

When deciding on TIG vs MIG welding, you need to consider the final joint, the metals, and the type of weld you intend to achieve in the long run. Both methods of arc welding are relatively easy to master with a bit of time and practice. Both approaches have their pros and cons, so make sure to check them in detail before applying one of the methods in your workshop.

Have you tried TIG or MIG welding before? If yes, what fillers did you use, and what was the result? Let me know in the comments below!

Sean Chapman

My ultimate goal is to provide insights that will help you effectively determine whether this or that tool or product suits your needs/budget or not. I test out home improvement tools at work on a daily basis and enjoy sharing my knowledge with D.I.Y-ers who have similar questions to the ones I used to have. I realize how important choosing the right tools is, that’s why my approach to every review I publish is very responsible.

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