Today, every nation talks about development in every aspect of human life.
We talk about infrastructural development, industrial development just to mention a few.
For development to actualize, welding plays a very big role, because almost everything we use in our homes, offices, construction sites, hospitals are in one way or another being welded.
Welding as well as a significant role in the military, automobile industries, telecommunications sectors, academic, maritime, and in every aspect of human life.
It acts as a protection for the skin in the sense that it shields humans from UV light. For this reason, most of our home roofs have been welded, including the chairs and tables we use. Some of the cars we drive are welded too.
Welding as it is called has different areas of specialization, such as Gas Metal Arc Welding, pipeline welding, underwater welding and structural.
What Is MIG Welding?
MIG welding refers to metal inert gas. The American society of welders (ASW) call it Gas Metal Arc Welding (GMAW).
It is also called Metal Active Gas Welding (MAG). In MIG welding, a thin wire accesses the electrode. This wire is fed on the spoon mounted on a gun or inside a welding gun, into a flexible tube and out of the muzzle of the welding gun or torch.
This is fed on continuously when the trigger on the welding gun is pulled. It also touches on the welding current and a shielding gas-electric arc form between this wire electrode and the workpieces.
Both metals above their melting point mix together, solidify and join the workpiece into a single piece.
Here, the metal to be joined in this part is the Base Metal. Then, the metal that comes from the melting wire electrode is called Filler Metal.
MIG welding adds Filler metal to the joined metal because the wire electrode metal is been used.
MIG welding is also called the CONSUMABLE ELECTRODE PROCESS. Here, the MIG wire passes through the wire Filler into a flexible tube or conduit liner, making the wire go through the hose or weld leading its way to the torch nozzle.
The wire is then fed through a conduit tip at the nozzle, and comes out of the point of the welding. Also, the Shielding gas is fed through the welding lead. It goes out of a gas diffuser and flow of the nozzle.
This shielding gas which mixes with CO2 protects the melted metals from reacting with oxygen, water vapor and other things in the atmosphere. The shielding gas is stored in a high-pressure cylinder; the pressure is reduced to a usable level by a device called a Regulator.
In MIG welding, all the machine control is set on the machine itself, most importantly are the polarity, wire speed, and voltage. The trigger in the gun is simply regulatory on/off switch.
For most MIG welding, the current is a direct current (DC) in which the electrode is usually positive, and the workpiece is negative. The term DCEP indicates that there is direct current and the electrode is positive.
This is also called the Reverse Polarity. The DCEP is a merely descriptive term in an electric circuit in which the current flows in a loop cycle.
The current in MIG welding flows in a full circle from machine to torch into the work and back to the machine. This brings us to the question of the day.
In short, MIG Welding is an electric arc welding process which uses a consumable wire electrode, and filler metal is added automatically and the shielding gas comes from a high-pressure cylinder to join the metals together.
What is MIG Welding Used For?
- It’s a high productivity, low welding cost process.
- It can be used to weld all type of commercially available alloy and metals.
- MIG welding is used for welding the body of cars.
- Used in maintaining a high operator duty cycle, by using a continuously fed electrode.
- On all types of metals and alloys commercially available.
- It is ideal for multi-pass welding.
- This process is ideal for mechanized welding.
- It is used for x-ray welding.
MIG Welding Techniques
We said technique in general terms is the practical method of achieving something or carrying out something specific especially ones which require a given skill.
The following below are the important techniques every good MIG welder should be aware of primarily;
- Knowing the materials needed for work, like your safety boot, Goggles to protect your eyes, heat resistance gloves, flameproof jackets, and position of fire extinguisher nearby in case of fire outbreak.
- Knowing how to handle the MIG welding equipment’s, how to change electrode settings, how to apply the gas properly, how to change the welding wire and to also know how to lay a bead with the welding gun.
- Knowing how to keep materials ready properly before starting welding, you have to make sure that all the metal pieces needed for the operation are clean and free from rust or are painted.
- If not, clean them and paint the ones needed to be painted, because once contaminants get on the weld, it will reduce the strength.
- Handling of the welding gun, since MIG welding is about torch and gun, you have to know how to pull the trigger and touch the wire to the tip. The metal brings an electric current that will heat up the workpiece to make it join together.
- How to position the wire tip on metal properly.
- Know the angle which can give you the best position during the welding process.
MIG Welding Tips for Beginners
- First of all, as a beginner, you must learn to keep your welding environment clean to avoid any unlikely hazard.
- Always adhere to safety instructions, and wear your safety equipment properly at all time in the welding environment.
- Practice often with the laying of bead and making of metals to be perfect.
- Make research, read books about MIG welding, watch YouTube videos and do some Internet surfing to improve your knowledge and skills in MIG welding.
- Know all the machine control buttons, and how to control each machine and equipment.
- Before you start any welding process, make sure you check the content of the Gas available and know the expected time that it will last you.
- Don’t rush! Follow a step by step practice starting from knowing the different types of joint we have, and the positions which you need to take in each welding procedures to avoid weld deflects.
- Always switch off the machine after use.
Frequently Asked Questions
How important is a good electrical ground in MIG welding?
Ans. In MIG welding, a good electrical ground is very important compared to other types of welding, because the welding current may find an unknown way to the machine and destroy components in the welding circuit.
How important is the contact tip in MIG welding?
Ans. It is very important because it gives a smooth flow in the welding current. For efficient high-quality welding to be achieved, the contact tip must be changed after every 100lbs.
Does shielding gas affect the quality of finished weld?
Ans. No, except there is less percentage of Argon in your mixture, but the proper mixture of CO2 and Argon, in fact, will increase the quality.
Does my choice of MIG welding wire really affect the quality of the welding?
Ans. Not really because, for instance, if you’re are working on clean steel and you are using wire like Super Arc L-50 MIG wire, all you need to do is to upgrade it to Super Arc L-56 to give you the perfect result that you need.
Are there any other tips you can provide for higher quality MIG welding?
Ans. Yes, first of all, keep your welding current lower to attain a good chance of success while working on thinner materials. Also, in order to create a very good weld, make use of smaller diameter wire.
MIG Welding is a special and benefiting profession in society with very few experts and the jobs are of a considerable wage range and demanding.
So I strongly advise any person trying to take this profession to be zealous and law-abiding because any form of reluctance to follow instructions can or may lead to great danger or risk.
Therefore, I advise beginners to follow instructions of experts and always endeavor to practice and improve their skills and the sector at large. Remember your safety is more important.