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The first question that a person gets in his/her mind when they begin their career or have an idea to do welding is, “Is Welding Easy”? If you purchase the right equipment, gather immense knowledge and do a lot of mini-projects, you can find welding to be under your command.
Even though you have a lot of experience in welding and MIG welding techniques, brushing your skills and staying precautionary is essential for a welder to keep his charm alive. Do you know the basic fundamental rules that are essential to be kept in mind for a welder of any skill level?
- Setting your machine with the right settings
- Clean metal and joints that are regularly checked
- Right technique and equipment used
- Comfort and precautionary equipment include welding glasses, gloves, shoes, and a dimming helmet.
Other welding processes like Stick or TIG welding do not require perfect settings. All you got to do is set up the machine and you can do it.
The Basics
MIG welding is an arc welding process that has a long solid wire electrode that is fed using a welding gun to attack/join two metal joints using a filler metal. Shielding gas in the right amount is also sent through the welding gun which helps protect the weld from any sort of contamination.
MIG stands for ‘metal inert gas’ welding whereas its original scientific name is ‘Gas Metal Arc Welding (GMAW) using which a welder can fabricate new objects and goods that may prove useful to him/her and also repair certain metallic things that you might own.
Safety First
It is highly recommended to get a proper set of welding protection equipment like a pair of welding gloves, glasses, dimming helmets, and working shoes along with a good-quality fire-proof jacket.
No matter how experienced you are, a small mistake can ruin your entire life. Reading certain articles and welding manuals can give you an idea about which equipment to purchase and from where.
Metal Preparation
The MIG wire is not resistant to rust, dirt, oil, and other contaminants. It is not like a stick or arc-welding where there are not many additives. You must have a good quality metal brush or grinder that can help in cleaning the metal as well as its joints.
If you are a beginner, you might not have much idea about butt joints. To get much thicker and stronger welds of metals, you must bevel the joint to make it highly penetrable and is essential for butt joints.
Equipment Preparation
Make sure all the cable and wire feed connections are first made correctly ad does not have any damage before starting your welding process. MIG welding requires a DC electrode to be positive and the ground negative. Make sure the polarity is maintained properly.
You need a shielding gas supply for MIG welding and hence turn it on and set its flow rate from 20 to 25 cubic feet. If you have an issue with the flow of shielding gas, purchase a new hose and install it.
Do not use too much or too little tension on the drive rolls as well as the wire spool hub. Make sure to remove any excess spatter and dirt that is present in the contact tubes, hose, contact tips, and liners before beginning welding.
Wire Selection
For steel is it recommended to use the ER70S-3 for all-purpose welding and ER70S-6 wire for welding that is done on dirty and rusty steel. The wire diameter must be in the range of 0.03 inches that is used in welding home and motorsports applications. If you need to weld using thinner metals, use a 0.023-inch diameter wire to reduce heat.
Gas Selection
The best shielding gas concentration that can be used as an all-purpose shielding gas is 75% argon and 25% carbon dioxide, especially for carbon steel. It produces hardly any spatter, good-quality bead appearance, and does not penetrate through thin metals easily. If you use a 100% carbon dioxide shielding gas, then it will easily penetrate through the thin metals.
Voltage and Amperage
Depending on the thickness of the metal used, type of metal, joint configuration, amount of shielding gas used, welding position, wire speed, and welding technique are all considered for setting the voltage and amperage of current supplied.
Wire Stick-out
The length of the electrode that is unmelted and sticks out from the tip of the contact tube is known as ‘Wire Stick-out’. The general wire stick-out length is around 3/8 inches of wire.
Push or Pull
The ‘push’ technique, also known as the ‘forehand’ technique is the process where you push the gun away from the weld puddle. This process generally produces lower penetration and a wider bead because the arc force is directed away from the weld puddle.
The ‘pull’ technique, on the other hand, also known as the ‘backhand’ technique, the welding gun is pointed back at the welding puddle and then dragged (taken away) from the deposited metal. Dragging generally increases penetration and makes the bead narrower.
Travel Angle
It is defined as the angle relative to the gun in a perpendicular position. General travel angles range from 5 to 15 degrees. If you do weld with a travel angle of more than 20 or 25 degrees, then more spatter, arc instability, and penetration is less.
Welding Position
The gun angle concerning the welding joint angle is known as the ‘Work Angle’ and differentiates the various welding positions that we have got. They are:
Flat Position
A ‘Flat’ position means that it is a ‘Butt’ weld with a 180-degree joint. For this process, you must hold the gun at 90 degrees to the welding joint with a work angle of 5 to 15 degrees. A further forward and backward motion can help in complete usage of the filler metal applied in the joint and can help fill a larger gap.
Horizontal Position
The effect of gravity should not define how good or bad you weld metals. Hence, the gun work angle must be reduced to about 0 to 15 degrees, without which the filler metal might get spread all over the weld joint and get sagged.
If you are doing a multi-pass weld, make sure the weave beads are used to fill gaps and joints as the fit-up will be bad. Make sure that the weld and the base metal are joined strongly without any gaps in them.
Vertical Position
When it comes to vertical welding, doing both up and downward will be hard. You might need a pre-weld setup ready to make sure your vertical welding can be done efficiently and with ease. Again, as we go against gravity, it is better to reduce the voltage and amperage to about 10%-15% of its initial values.
This method is highly useful for welding thin metals as vertical welding causes less penetration into the metal because the travel speed will be more. You can avoid any form of melting of the metal. So, to prevent burning up of metal, for the ‘vertical-down’ method, begin welding at the top of the joint and weld down, and for thin metals move the wire away from the welding joint.
The ‘vertical-up’ technique on the other hand begins at the bottom and goes up the joint. Hence, this helps better penetration of thicker metals in this case. Once again, the travel work angle is reduced around 5 to 15 degrees from the initial angle. A small weaving motion of the gun can help control the size, shape, and cooling effects of the weld.
Overhead Position
Overhead position of welding can use three techniques of welding namely drag, push, and perpendicular. Here, we work against gravity and hence the travel speeds are recommended to be kept very high to weld joints properly. Thinner weave beads are better. You can have the weld under control by reducing the voltage and amperage.
Welding Patterns
Joint Preparation
Setting up a clean and perfectly shaped joint is very important and it will get better if you are a professional welder. Correctly set welding machine, clean joint, and the most comfortable position are more important than a welder’s technique used. What patterns do is that the whole process becomes smooth and uniformly laid.
- Steady Motion
- Whipping
- Circles
- Weaves
Steady Motion
This is the most basic technique used in MIG welding which is commonly used by robots where welding is done is highly professional and perfect in the output produced. The key options that are seen to be correct are machine settings, electrode angle, and wire travel speed. There is nothing much to do here other than doing all the settings on point.
Whipping Technique
This technique is done using stringer beads or fillet welds. It is mainly done on joints of metals and keeps the puddle in the tight range of the weld. Here the joint is preheated to a good temperature and then the filler metal is put into it.
This technique is highly friendly and is used by beginners who are not aware of MIG welding techniques. It follows a strategy of two steps forward and one step backward.
Circle Welding Technique
This type of welding technique is a combination of both the Steady and Whipping techniques. They work quite easily on any kind of welding joints and the way it works might amuse you. It forms a tiny circle and then moves forward and repeats.
Weaving Welding Technique
The welders who need to do welding in a wider range of joints, then weaves are used. It can act as a stringer bead for wide and big joints in a single pass. It does not produce any distortion or cracks in the weld. This welding technique is not preferred in shipping yards.
Advantages
- Higher Productivity: You can save a lot of time and utilize it for leisure and design purposes as the welding machine can help you weld the metallic parts easily.
- Simple: This is one of the most advantageous things about MIG welders. It is the simplicity to ‘learn’ to use the particular machine that any beginner or an amateur can get a hold of by following the manual and guidelines.
- Great Welds: MIG welder can get you a larger and clear vision of the weld pool. This gives you a wider range of workflow along with good control over the wire-feed, travel speed, and whatnot.
- Clean and Effective: Since the MIG uses a shielding gas that helps it to protect the arc. There is very little loss of essential metal and no slag formation in the weld too.
- Versatile and Quick: A MIG welder can be used to do repairs and mini-projects by a welder at home and it can also be compatible to do welding jobs in large-scale companies. It takes very little time to weld metals, with good quality and immense control over the weld.
Dis-advantages
- Cost: MIG welding equipment is generally expensive even with unknown brands and hence welders think twice before purchasing one. In the long run, it might be really handy though.
- Outdoor Welding: MIG welders are not portable and moreover, they cannot be used to weld any metals outdoors as they are not water and dust-resistant. The shielding gas also gets affected badly due to excessive outdoor wind.
- Thick Metals: MIG welding is only suitable for thin metals. It cannot do proper penetration in thick metals.
- Metal Preparation: The time taken to get the welding metal ready is high. This is because the metal must be free of rust and dust or even moisture around it.
- Limited Position: The fluidity of the weld at joints and heat input that a MIG welder gets is not at all suitable for vertical or overhead welding positions.
Sean Coby is a welder par excellence and well respected among the welding community in Woodbridge, VA. He prides himself to be the fabricator and mechanic in the automotive/ diesel industry for the past more than eight years now. As the chief editor of his https://weldinginfocenter.com, he shares his experience to be safe during welding and to take proactive steps for becoming a successful welder like him.