24 Important Facts about Mig Welding

Important facts about Mig welding for your refreshing knowledge of this universal welding process.

Welding is a hard work. That’s why there needs some relaxing time to refresh yourself after all sweat, even burns you have sacrificed. Below are some facts about Mig welding that will help polish your knowledge and give you some ‘wise’ relaxation. This below list can also used as the note-taking sheet for brand-new welders to remember the key points of Mig welding and all welders to recall basics of this process. Hope you heart it!

• Mig welding is another name of Metal Inert Gas Welding.

• Developed in the 1940s.

• Considered a semi automatic welding process

• First called Gas Metal Arc (also, GMA, Gas Metal Arc Welding). There are some different Mig welding names as a result of types of gas used (Inert gas vs. non-inert gas).

• Mig welders have a handle with a trigger. The trigger controls the wire feed.

• Most used in fabrication shops that come with high production and unlikeness of wind blowing away the gas shielding.

• Employs a consumable wire electrode during the welding process fed from different spool sizes.

• Unlike just about all other welding processes, Mig welding includes one standard polarity type and voltage type. The voltage is direct current (DC). The polarity is DC electrode positive.

• The power source for Mig welding is ‘constant voltage power supply’ while Tig and Arc welding uses ‘constant amperage power supply’.

• Mig wire/ electrode types are associated with types of metal to be welded, type of transfer, abrasive resistance, position to be welded.

• Common Mig welding electrodes are the solid wire of thickness ranged from .023, .030, .035, to .045.

• Requires use of a shielding gas.

For those who may be interested in:

What is Your Definition of Mig Welding?

8 Useful Tips for Mig Welding

• 3 common types of gas for shielding in Mig welding are: Argon, Carbon Dioxide, Helium.

• The shielding gas used needs be a match with the electrode, and base metal.

• 4 transfer types used in Mig welding are short circuit, globular, spray, and pulsed spray.

• Transfer types are associated with metal type, shielding gas, and machine settings.

• Just about every metal can be Mig welded.

• Weld area is critically clean.

• Brings out a uniform, clean weld bead.

• Brings out a weld bead free of slag.

• Maintained by shielding gas.

• Facilitates welding in all positions.

• Produces long welds without repeated starts or stops.

• Requires less clean-up.

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What is Your Definition of Mig Welding?

 Below specify definition of MIG welding along with its pros and cons. Read on and don’t hesitate to leave your viewpoints of this process.

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8 Useful Tips for Mig Welding

MIG welding (also, Gas Metal Arc Welding (GMAW)) involves a process that takes advantage of a persistently fed solid electrode, shielding gas from an external supply, and electric power for melting the electrode and depositing this molten material in the welding joint. The equipment employed automatically regulates the electric characteristics of the arc. The welder is required of the only manual control (travel speed, travel direction and gun positioning). As far as appreciate equipment settings come, the power supply will give the needed amperage for melting the electrode at the required rate to maintain the pre-selected arc length (voltage). For instance, a higher stick-out resulted from drawing the torch back from the work piece leads to a decrease in current from the power source. That way maintains the similar electrode heating and returns the arc length to its pre-set condition. The selection of filler metal should be closely associated with the base material to be welded. Regarding MIG welding, the filler metal helps reinforce the completed welding joint aside from conducting current to the arc zone (and melting base metal and electrode as a result).

MIG welding can be employed on various metals, and base metals of numerous different thicknesses. Its successful application is related to the appropriate selection of:

• Electrode (composition, diameter, packaging)
• Shielding gas (type, purity, flow rate)
• Process variables (current, voltage, mode of metal transfer and travel speed)
• Equipment (power supply source, welding gun, wire feeder)

Why Use MIG Welding?

• MIG welding is a high-productivity, low-cost welding process
• It can be used for welding all types of metals and alloys commercially available
• Welding can work in all positions with right selection of equipment and parameters
• Using a persistently fed electrode maintains a high duty cycle and minimizes the defect occurrences
• In-depth weld penetration can be gained, which enables the employment of small weld sizes for equal weld strengths in some applications
• There requires minimal after-weld clean-up as a result of the absence of a slag cover on the weld bead
• Welding speeds and rates of weld metal deposition are higher than those got with stick welding
• Perfect for multi-pass welding (with appropriate filler metal selection)
• Less manual skill is required comparatively to stick welding
• Fume rates come at really low levels as compared to stick welding and flux cored welding
• Compositions and diameters of filler metal are widely selected for welding thick or thin material
• This process is perfect for mechanized welding.
• This process provides enhanced electrode deposition efficiency in comparison with stick welding and FCAW
• Welds of X-ray quality can be produced.

What are Downsides to MIG Welding?

• Weld equipment is considered more complex, more costly and less portable compared to stick welding
• It is difficult for the required welding torch to reach into the constricted areas. Plus, the good gas shielding is needed, which makes the torch be quite closer to the weld area.
• The welding arc with its gas shield is necessarily protected from drafts, which may cause the shielding to be blown away from the arc. This doesn’t facilitate the use of this process outdoors unless the protective shields are placed around the working area
• Pretty high levels of radiated heat and light might cause operator’s discomfort, initial resistance to the process
• Burn-through commonly occurs when welding especially thin materials (smaller than 1/16”)
• Pertaining to traditional transfer when welding out of position, rates of weld metal deposition are less than those obtained with flux cored welding
• This process fails to perform well in which base metal contamination is an issue. The base metal is required to be clean and rust-free
• Lacking in fusion defects may induce where process parameters are wrongly set. This is extremely critical when welding base metals are thicker than 1/4”

Are you finishing this read? What is your definition of MIG welding? Your opinions of its pros and cons? 

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8 Useful Tips for Mig Welding

Make use of those tips to better your MIG welds!

While being trained at school, more experienced after practical work, Vietnam welders are also encouraged to draw lessons along the way and utilize welding tips to smooth their work process and perfect their finished products. There are useful tips as related to Mig welding that welders can make best use during their work.

1. Always begin with clean materials

To work with contaminated or dirty materials is the fastest to ruin a weld. Take it a note to always clean up the workpiece you are about to weld and ensure the metal is really clean and contaminate free. Examples of things that can contaminate the weld include rust, corrosion, old paint, grease, oil, or just plain dirt. Better the weld by getting it off.

2. Use the best possible welding wire for Mig welding.

This will pay off in better welds. Then get the best possible wire you can afford. Of course, you can save money buying inferior wire. Sure there is plentiful rubbish out there in the market, but it won’t last long. Your welds will just end up being poor quality and having to be redone later.

For Mig wire, always find the one with nice copper coating, accurate dimensions and without being oversized at any point along its length.

3. When you can, always use an auto darkening welding helmet

You sure will pay a little more, which will make up for the extra time you would earn to grind and redo your work. Rather, it takes some more pay to avoid lag time and have better weld. Using an auto-darkening helmet, you will kill the lag time from when you begin your weld, to when a standard helmet is flipped down into place. That very brief moment of time can make you lose track of your welding path and cause lots of extra worker afterwards because you have to grind, redo your work.

4. Always use the Earth clamp

As the welding process is just like a high voltage electric circuit, any circuit break can induce welding problems. A good clamp with a strong spring just prices around $20, and is worthy of money. One way for eliminating those circuit breaks is using a good Earth clamp, and making ready for the metal underneath by sanding off any corrosion or paint.

Bear in mind that a bad ground is one of the biggest Mig welding problems. Always ensure that your clamp comes with a good, clean ground surface for clamping onto; otherwise, you will be in trouble before you get started.

5. Get a good tip for Mig welding

You need a good Mig welding wire for good weld production. Also, you need quality contact tips. There are many cheap contact tips on the market these days; the internal surface of the tunnel that the wire feeds through can be rough or uneven. That can result in fickle or unstable welding arcs, inconsistent wire feeding, and other problems.

6. When Mig welding, use the right shielding gas

You can use directly CO2 when Mig welding though, a 75% argon and 25% CO2 mixture is rather much standard in the welding industry.

7. Have the Mig welder set to the right polarity

Just remember that when Mig welding, polarity is associated with the type of welding wire you use. If you use bar wire, you will need reverse polarity electrode positive for a good weld. For flux core welding wire, you will need reverse the polarity.

Because Mig welding machine doesn’t include a switch for polarity change, you will have to do this manually.

8. Use a good anti spatter compound

If welding is done with flux core wire, welding spatter is part of the process. Still, you can decrease the spatter for cleaner welds by using a good anti spatter compound like LPS aerosol 02116. Another upside of the LPS compound is that it is water based and non toxic, then unlike some cheaper compounds, it won’t do any extra damage to welder’s health.

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