The Three Amigos: MiG, TiG, and Stick
Welding is the glue of this company—better yet, the molten metal that keeps us fused. The reason for that is, of course, that welding is the mechanism that moves the fabricating along.
Welding, in simplest terms, is the process of fusing pieces of metal together by adding molten material through heat (around 6500° Fahrenheit). The three types for today (MiG, TiG, and Stick) all belong in the overarching category of arc welding. Arc welding uses a continuous stream of highly densified electricity—forming an electrical current (an arc)—to produce heat hot enough to melt metal.
Without getting into technical science, the process of welding can be further understood by first, breaking down the components generic to welding, and then explaining the variables of these components in these types of welding.
The components of welding are fourfold: the electrode, the filler, the gas, and the base material.
The electrode is the conductor, the path used by the electricity to pass through. For welding, the electrode can be consumable or non-consumable; that is, it can be consumed, acting as the filler, melting to fuse the metals, or it can be not consumed, where it conducts without acting as the filler, requiring a separate filler.
The filler is what melts to fuse the metal and build up a joint. It fills and penetrates the metals, forming a bead of additional metal. Forms of filler include: a stick of metal coated in minerals or a spool of metal wire.
The gas for arc welding is inert. Inert gas does not chemically react; it prohibits chemical reaction. The need for it is that if a chemical reaction does occur due to rust or contamination the weld is weakened. This is called atmospheric contamination. The gas protects the weld from atmospheric contamination by forming a shield around the weld, which is why the gas used is called a shielding gas.
The base material is the metal pieces that are being welded upon, fusing them together. In arc welding, the base material conducts electricity by having a cable attached to it. The ground cable connects back to the welding equipment so that when the electrode makes contact, it completes the electrical circuit forming an arc.
With those components introduced, the types of welding are more understandable.
First is MiG, and that means Metal Inert Gas. MiG uses a spooled wire that functions as the electrode and the filler. Loaded into a wire feeder on the welder, a pull of the trigger completes the circuit as the wire conducts enough energy to melt itself and penetrate the base material. MiG is considered the “hot glue gun” process because the welder points and shoots. The shielding gas comes from a pressurized cylinder connecting by tubes to the feeder so that gas flows over the weld continuously.
Stick welding uses a stick as the consumable electrode acting as both the conductor and filler. The gas comes from the coat of minerals wrapped around the stick, which when it heats up, it vaporizes forming a shield around the weld, protecting it from atmospheric contamination. The stick melts and forms the molten material that penetrates the base material, fusing them together.
Then, there is TiG, which stands for Tungsten Inert Gas. Tungsten is a tough metal that can withstand high heat before melting, so the tungsten acts as a non-consumable electrode. The filler material is a metal rod that melts under the arc. The shielding gas continuously flows over the welding, preventing contamination. Because TiG uses a non-consumable electrode to carry the electrical energy, filler materials are relieved of that duty. This allows for a variety of metals to be welded such as brass, aluminum, and other non-ferrous alloys.
These three types of welding have their benefits. Stick is suitable for onsite welding because it can be done under poorer conditions as the shielding gas comes from the chemical coat. MiG welding allows for clean, deep welds with easier to use equipment. TiG requires profound technique but produces the cleanest welds possible on a variety of materials.
These three pictorial illustrations come from our friends at Welding Supplies from IOC:
Our shop knows and uses these three types for the different challenges that jobs present to us. Our customers can rest assured we will use the right process for the right job.