Welding has been one of the most popular means of joining metal plates together over centuries. It ensures a chemical bond between metals rather than just a superficial one. Welding has also seen various progress due to technological advancements taking place. One such new entry to welding would be Metal Inert Gas welding. This has been a popular option for many new-age welders looking for a fine finish on their products. So, if you are a welder and looking for some deep knowledge about how to MIG weld, continue reading below.
What is MIG Welding? – Definition
MIG welding belongs to the family of arc welding. This consists of using a solid wire electrode that is initially heated and then fed into the region where weld is being done. Just like any other welding process, it consists of heating two metals to their melting points so that they can chemically react with one another and form a bond. the welding gun also helps to provide a shielding gas. This, in turn, helps protect the welding pool from any impurities present in air.
Components that you need for MIG welding
- The first thing you would need would probably be a MIG welding machine.
- Next would be a power source. Most of the time, It comes with it, or you need to purchase one separately.
- A set of MIG welding wires would act as an electrode during the process.
- You might also need a shielding gas to facilitate the welding process.
- Lastly, a set of tools and accessories to aid the welding process and help to impart a better finish to the welded surface.
How to MIG Weld Aluminium or Stainless Steel?
- The first step would be to move the fume extractor over the area to be welded.
- Clean the work surface and wear the MIG welding safety equipment like gloves, auto-darkening welding helmet and apron.
- Next, attach ground clamps onto the workpiece to ensure its stability.
- Confirm that the adjusting screw is set loose and in position.
- To ensure that pressure stays constant, open the knob to the pressure cylinder.
- Turn the adjusting screw till it reaches an optimal pressure of 15-20 CFH.
- Next, determine settings for welding and choose an electrode that might suit the process.
- Now turn on the welder machine to begin the welding process.
- Adjust wire speed and voltage concerning the workpiece and ease of doing work.
- Ensure that you feed a sufficient quantity of wire into the welding torch.
- Now you can start to weld pieces together.
- Once the process is finished, turn the wire speed to the lowest setting.
Can you MIG Weld Aluminum?
Yes, you can MIG weld aluminum. Though aluminum is hard to weld compared to the steel, the results will be more satisfying with the MIG weld than with the TIG. In many cases, MIG welding aluminum requires to use the shielding gas of 100% Argon. But if you are welding the thick sections it is better to add the Helium for deeper penetration. The technique to use aluminum MIG welder is Push welding technique which gives better results compared to Pull.
Can you MIG Weld Stainless Steel?
Yes, Stainless Steel can be MIG welded which gives the high-quality results compared to the stick welding. It requires 98% of Argon and 2% of Carbon dioxide for MIG welding stainless steel. Coming to the wire, .030-inch diameter stainless steel welding wire suits best for most of the projects. But for thicker base sections, you can choose between .035-inch to .045-inch wires. It is better to use the Push technique or you can use push-pull method when required. For deeper penetrations, you can go for Pull technique.
What are Process Characteristics of MIG Welding?
This welding technique can join together metal sections across multiple thicknesses. The arc that is formed comprises an extremely high temperature. This process helps melt metal on the surface of the workpiece and remainder from electrodes. It is generally fed through copper tubing during the welding process. This is considered a semi-automatic process as both processes of feeding the electrode and maintaining arcs are automated. Only travel speed and position of elements are under manual control.
Arc Characteristics of MIG Welding Process
- Short-Arc System: wire used as an electrode tends to short-circuit with a welding setup. This, on the other hand, helps to control the rate at which the weld globule tends to grow. greater cross-section becomes, less short-circuiting occurs.
- Dip Transfer: main advantage of this technique is its overall flexibility to welder. The weld pool generated is comparatively small and makes it easier to control. Dip welding can sometimes lead to uneven distribution of heat, creating problems during the process.
Types of Arcs used During Process
- Dip Transfer Arcs: They are used for low voltage and low wire speed projects. With this process, it is possible to weld in any direction.
- Intermediate Arcs: This displays short-circuits and sprays transfers after small time intervals. arc is often associated with the problem of splattering and is generally avoided.
- Spray Arcs: These show almost no interruption due to short-circuiting and are a very seamless process. Weld metal transfer happens at a very high speed and gets deposited as fine droplets.
- Pulsed Arcs: Pulsed arcs are special because they cut down almost all possibilities of short-circuiting. This process is carried out in intermittent, short bursts of pulses.
- Rotating Arcs: These are commonly used for thicker workpieces in cross-sections. They provide extremely high heat input, and filler metal is deposited in the form of rotating motions.
- Combined Arcs: These are made up of pulse and dip transfer arcs. These provide the best of both worlds, i.e., they provide good heat input and a high level of control over speed.
Advantages of MIG Welding
- The MIG welding process is extremely fast. This is because the electrode is continuously fed through copper tubing.
- The whole process of this welding is comparatively very easy. This is because multiple facets of process are completely automated, and manual intervention is needed less.
- This welding process is completely free from any flux during the process. As a result, welds being formed are of high quality.
- With the MIG welding technique, it is possible to deposit more metal per round of the welding process. This makes the process easier for complex workpieces.
- One can use MIG welding across a variety of cross-sections. They are some of the most preferred weld techniques for thicker materials.
- There is very little room for the welding process to stop continuously. This ensures a smoother experience during the welding process.
- the amount of electrode loss associated with this process is very low. Unlike other forms of welding, you can end up using almost the entirety of the electrode.
- MIG welds can be used for a variety of metal surfaces. process works for all, from considerably reactive metal surfaces like aluminum to inert ones like stainless steel.
Disadvantages of MIG welding
- While a MIG weld setup can last you for years, initial investment can be quite hefty as it can get extremely expensive.
- MIG welding has more components compared to a normal welding setup. As a result, it becomes difficult to manage this upkeep. These also tend to require frequent servicing compared to others.
- These welding setups are not very convenient to carry and lack a lot of portability. The welding torch is quite big as well. This makes it very difficult to weld in some more complex shapes and edges.
- MIG welding is not the best option if one plans to go for a vertical or overhead welding process. heat input tends to be unevenly distributed, and one can easily end up with a puddle of melted material if one is not careful.
- Since MIG weld uses power to provide high heating rates in a short span of time, it may often lead to burn-throughs. For thinner workpieces below 5 mm, this can be a serious issue. Burn-throughs in welding can be commonly seen as tiny holes on the weld surface.
Tips and tricks to use for MIG welding
- Welding as a whole calls for greater safety. This would not be any different in case of MIG welding. Ensure you have all safety gear on and work in a well-ventilated space.
- Have a clear understanding of the type of material and surface you plan to weld.
- Clean welding surface extensively to get rid of any impurities that may cause porosities at a later stage.
- Ensure that your electrode wire does not jut out a lot from the gun.
- Try to have both hands on a welding gun for improved stability when welding.
- For better penetration into the metal surface, keep the arc up front near the metal puddle that’s being formed.
- Ensure that you are replacing contact tips frequently to improve the quality of your weld.
MIG stands for Metal Inert Gas. It is also known as MAG which stands for Metal Active Gas.
MIG welding is best used for repairing Motorbikes, RV, Cars, Vans, SUVs. However, it is also greatly used in Construction and High Production Manufacturing.
In MIG welding, if you push it results in lower penetration while pulling results in deeper penetration. Pushing gives a wider and flatter bead, where as pulling gives a thinner and rounded bead. As both MIG welding techniques works equally good, you can use either pulling (drag technique) or pushing (forehand technique) as per your convenience.
Four types of shielding gases are used for MIG welding which includes, Oxygen, Carbon Dioxide, Argon, and Helium. Among these, Argon is the best gas to used for MIG weld. You can also mix Helium or Carbon for best results.
Solid and Flux-core are the two main types of MIG welding wires.
The most common MIG welding patterns are Circles, Steady Motion, Weaves and Whipping.
It is important to remember that welding requires a fair amount of expertise. This is something that you cannot effectively use without prior practice. Welding requires a considerable amount of safety gear in place as well. Without any safety setup in place, this can also be a hazard. Before welding, it is important to keep metal surface and electrode compatibility in place. Proper preparation of work surfaces is also an important precursor to welding. So if you are looking forward to using welding to weld joints together, consider giving MIG welding a try.