Beginners guide to GMAW welding

You may have heard of gas metal arc GMAW welding. It’s a process that joins metals with electric current and gas through electric arc. Sometimes called metal inert gas (MIG) and metal active gas (MAG). In this article, we will cover the basics of gas metal arc welding and how to get started with the process.

There are two types of GMAW processes: solid wire electrode and flux-cored. Solid wire electrode is more versatile, but flux-cored is more common because it’s more cost-effective. We’ll focus on flux-cored gas metal arc welding in this article for easier understanding.

The process begins with selecting the proper equipment and placing the parts together in a joint configuration. Next, your welder must carefully control the amperage, voltage, and polarity to ensure that there’s enough heat for proper penetration into the joint surfaces.

What is GMAW welding?

The process is a joining method that uses electric current and a molten metal arc to heat, pierce, and melt two pieces of metal together.

The GMAW welding process, which evolved in the late 1940s when a continuously fed electrode wire replaced the tungsten electrode in GTAW, quickly became popular due to its low cost and quicker welding time. Today it is used in industries such as construction and manufacturing; car racing; vehicle production; pile driving (a type of heavy machinery); presses (a machine that compresses or squeezes material into desired shapes).

Types of Gas metal arc welders

There are four types of GMAW processes:

Short circuit

Short circuit is the coldest form of MIG welding, which uses low voltage. The welding wire touches metal and electricity goes through to create a short circuit effect. This makes for wet metal puddles that quickly solidify and fuse materials together.

Spray

This process involves melting the wire to fine droplets, which are then sprayed or misted onto weld joints. The process relies on high heat input and constant voltage. It also sends a stream of metal from arc to base material for this method.

Globular

The globular transfer method is similar to the short circuit method, but it has a higher heat input and wire that’s heated for longer periods. This creates a larger weld pool which drips into the joined area.

Pulse

While the spray arc method is similar, it has to be modified in order to address its disadvantages. Welder’s will pulse the voltage many times per second and let a droplet form at the end of their wire that gets pushed across into the puddle. The pulsed spray transfer is more functional and flexible than other methods, but can also be expensive due to requiring high-end MIG welding machines.

How to get started with GMAW welding

If you are welding, the equipment needed is dependent on what exactly you’re doing. But here’s a list of some of the essential things most people would need:

  • Welding Gun
  • Wire Feed Unit
  • Welding Power Supply
  • Electrode Wire
  • Shielding Gas Supply

The process begins with selecting the proper equipment and placing the parts together in a joint configuration. Next, your welder must carefully control the amperage, voltage, and polarity to ensure that there’s enough heat for proper penetration into the joint surfaces.

3 recommended GMAW welders

Eastwood 180 Amp

Lightweight
Long ground, torch and power cables
30-180 amp welding range

Hobart Handler 210

Simple to use
Great performance for the price
A bit heavy at 80 lbs

Millermatic 211

Pro choice
Ideal for welding heavier materials
Portable

FAQs about GMAW welding

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