In the metal industry, it’s common to hear: “The person who kept our resistance welders running is no longer here!” Relying solely on tribal knowledge is no longer sufficient. Today, we are using outdated technology and equipment while trying to meet increasingly strict quality standards for a wide range of advanced steels.
When I first entered the resistance welding field, a projection nut simply needed to hold long enough for a bolt to be tightened. Standards have changed dramatically. Modern projection weld nuts must meet specific torque requirements, with each projection evaluated for quality. The challenge intensifies when welding steel that is exponentially stronger than the nut itself.
Does this sound familiar? Are you starting to sweat a bit cause you have been there or even worse – you are there?
How do you eat an elephant? “One bite at a time” – should come to mind! So, let’s break our “elephant” into smaller bites.
Key Challenges
Many companies face similar issues:
- The welding expert is gone.
- The team doesn’t know how to properly set up resistance welders.
- There’s uncertainty about whether the welders can produce the required welds.
- The criteria for a quality weld are unclear.
- Equipment must stay operational to meet production and quality standards.
- Welders that once performed adequately now fail to meet customer demands.
This has become a dilemma that is sweeping our industry. Solving these issues requires time, investment, and proper training.
“Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.”
Understanding Modern Metals
Modern steels are often called “exotic” because they behave very differently from the cold-rolled steels of the past. Each steel is designed to react in a specific way during welding. Understanding how a material responds to the resistance welding process is critical.
For example, I visited a plant sourcing steel from both Switzerland and Korea. Although both steels had identical specifications, technicians found they welded differently. Surprisingly, the Korean steel was preferred—not because it was higher quality, but because its higher electrical resistance made it easier to weld and provided a larger weld window. While Swiss steel offered better overall quality, Korean steel was more efficient for welding.
The key question is: What exactly are you welding?
- How does the metallurgy of the material respond to heat?
- Is it coated (galvanized, aluminized, galvanneal)?
- What is the thickness of the coating?
- Is it a spot weld or a projection weld?
Answering these questions is critical to achieving reliable, high-quality welds.
“I just want to weld the parts so they pass quality and get shipped!”
You must know what it is you are trying to achieve in order to hit your target.
It’s like flipping through a cookbook and saying, “I feel like cooking! What ingredients do I need?” You have to decide what dish you’re making first, then you can figure out the steps and ingredients.
Back to our resistance welding…What is the process of resistance welding? How does it make a weld? What components on the welder actually are involved in making a weld? This seemed so simple before! We turned it on, put a part between these copper thingy’s, stepped on the peddle, after the sparks, the copper thingy’s go up and the part is welded…hopefully!
If this is the level of resistance welding common at your plant, let’s start at the beginning!
Training
You need to understand what actually creates the weld nugget. Resistance welders are made up of components that each contribute to forming that nugget. To consistently produce quality resistance welds in a production setting, someone at your facility must have proper training and the necessary expertise.
What if we get some training for a few of our maintenance guys? Well, that’s good but don’t the maintenance staff focus on maintenance? Maintenance does need to know what the resistance welder components do and how to replace components, but you do need to have someone that can focus attention on the resistance welding process, especially if multiple welders are in operation.
There are several options for the training that you need. Not all subject matter experts are good instructors. They may know an exceptional amount of knowledge and have vast amounts of experience, but if they cannot pass that knowledge on to others, you don’t want them to instruct your group. A good instructor can pass the knowledge to the learning level of their audience. That
is one reason it is not a good idea to have operators, lead setup people, maintenance and management all in the same class. As an instructor, you try to make the information pertinent to the knowledge level each group can utilize. People have different learning styles which the instructor must utilize, so the knowledge can be passed to the individuals where they can comprehend and retain that information.
Training is the first step to understanding resistance welding.
Effective training should cover:
- Fundamentals of resistance welding (Force, Current, Time, Temperature).
- Common terminology for consistent communication.
- Core theory: how and why welds form.
- Reading and applying resistance welding charts.
- Welder components and their functions.
- Power systems and their effects on welds.
- Understanding weld control settings.
- Electrode care and maintenance.
- Proper setup and startup procedures.
- Managing heat balance.
- Defining and maintaining weld quality.
- Safety best practices.
Once you understand what makes that weld nugget and how to control it, you need to evaluate your present resistance welding equipment and processes.
Troubleshooting: A Three-Part Approach
When facing welding issues, focus on these areas:
- Welder
- Use a weld scope and force gauge at the weld electrodes to verify the welding parameters that you set are actually getting to the electrodes
- Without the proper test equipment, you are just guessing what values are at the electrodes
- Process
- Is the welder set to give you the best welds on the material you are welding?
- Are the best electrodes being used to make the weld nugget you must achieve?
- Are the electrodes being properly cared for?
- Is the part being positioned between the electrodes correctly?
- Is welder maintenance being addressed?
- Are you using the correct welder to do the welds you are trying to achieve?
- Material
- Have you researched its welding characteristics?
- Is there any contamination on the material?
- Is the material the correct thickness?
- Has the material changed? Maybe from a different supplier or manufacturer?
The Path Forward
There is a solution—but it requires a plan. Start by assessing where you are versus where you need to be. Then, create a roadmap that not only meets, but exceeds your minimum quality requirements.
Look for a one-stop-shop resistance welding partner—a company that offers expert training, reliable equipment, parts, service, and proven industry experience. Proper training is the foundation of taking control of your welding process.
There is hope! With the right guidance and investment, you can optimize your resistance welding operations and meet today’s demanding quality standards.
