Automotive Welding Through the Years

Spot welding is defined as the use of heat, generated by electric current resistance, to join two metal surfaces together. Like many inventions, it was created by accident, when Elihu Thomson fused two copper wires together in the course of an experiment way back in 1885.

Metalworking techniques such as spot welding and metal finishing continued to evolve in the 1920s and 1930s, resulting in greater precision and more accurate repairs. The need for quick and efficient repairs on military vehicles during World War II further drove the development of new repair methods, such as MIG welding and the use of plastic filler.

Welding forms the foundation of modern automobiles, ensuring safety and structural integrity.

In fact, about 5,000 spot welds are required to manufacture the average car! Welding is a process that lends itself well to automation, and new technologies are constantly improving the speed and accuracy that robotic welders are capable of.

Collision repair technicians rely on welding to repair cracked panels, damaged fenders, rusted metal, and other forms of vehicle damage, both cosmetic and structural. In addition to high heat, pressure can also be strategically applied to fuse metals together.

Autobody Welding Techniques, Equipment, and Safety

Let’s take a look at the different forms of welding used in autobody shops today:

1. Metal Inert Gas Welding (MIG Welding)

Also known as Gas Metal Arc Welding, MIG uses electricity to create a weld and fuse materials together. The electricity creates an arc between the base metal and an electrode, and the higher the voltage, the stronger the weld. This is the welding technique collision repairers use most often, since it is can be used to connect the widest range of materials.

A MIG welder consists of a gas shield and a filler material, which is fed through a wire that runs through the welder. This tool is faster than other welders, and also easier to operate, since it can be held and manipulated with one hand.

Sometimes, autobody technicians will also run silicon bronze wire through a standard MIG gun—an autobody welding technique known as silicon brazing. Since the silicon wire has a lower melting point than the base metals being joined, distortion is reduced, resulting in a smooth and visually appealing finish.

2. Tungsten Inert Gas (TIG) Welding

Dating back to World War II, TIG welding uses a tungsten electrode to create the weld, and it is the preferred method for advanced applications. Due to its suitability for welding aluminum and thin stainless steel, it is well suited for repairing the growing number of lightweight cars on the road today.

TIG welders must undergo extensive theoretical and hands-on training which covers torch control, filler rod feeding, foot pedal use, and how to choose the proper materials for a specific application.

3. Stick Welding

Also called Shielded Metal Arc Welding, stick welding is an older technique that is not used as often as MIG welding. As the name implies, it is also a type of arc welding, but it is effective only for iron, steel, and other heavy metals—not for aluminum or lighter metals.

Since it is more likely to result in weld spatter, cracking, and weak fusion, stick welding is generally less reliable than other welding techniques. For those reasons, most shops today do not rely on stick welding for day-to-day repairs.

Welding Equipment & Accessories

Collision repair welding technicians also need access to special equipment and accessories in order to do their jobs properly and safely:

1. A helmet and leather welding gloves: to protect vision, face, neck, hands and arms from welding sparks and light.
2. Welding Curtains and screens: government certified for safety, to protect the workspace from heat, fumes, sparks and UV light.
3. Welding Clamps: Used to hold the welding surfaces securely in place during the welding process.

It’s imperative for autobody shops to regularly inspect and maintain this equipment, particularly welders, to monitor emissions, leakage, grounding, voltage and wiring. Gun nozzles must be kept clear of spatter which can clog them up and lead to poor quality welds. Helmets must be regularly checked and cleaned to ensure structural integrity and a clear sightline.

Don’t Try This at Home!

As you can see, there’s a lot more to collision repair welding than you may have suspected. It may not look that difficult (and it might even look like something that would be cool to try), but even for experienced welders it can be extremely dangerous, and even fatal. It’s not something that anyone without the right tools, equipment, knowledge and safety training should ever attempt.

Here at Mitek, our team members have the expertise and experience to choose and execute the right welding technique for each individual repair. As always, we prioritize the safety of our technicians and environment with each and every weld. If your car needs welding in the course of a repair, rest assured that it’s in the most capable of (protectively gloved!) hands.