How To Troubleshoot Your Stud Welding System

A stud welding system is useful to any workshop, whether it is for an industrial or an amateur usage, to weld bolts or fasteners onto a metal part. From the building of a luxury cruising ship to the assembly of an electrical panel, stud welding has a lot of applications. Yours may be automated or in the shape of a gun, or you may have a sophisticated stud welding system that fits the high productivity of your plant.

As with any electric devices or with any specialized equipment, problems may occur. If your stud welding system is not working right, it is likely due to a bad connection or to a worn out part. There are some common issues that you may be able to fix yourself, so long as it doesn't involve unscrewing the welder. Listed below are common issues you may encounter while using a stud welder gun or any stud welding machine.

Ground Plugged At The Wrong Place

If you are getting too many projections while you are welding, which looks like there is a lot of tiny bits of metal poking out of the weld, your ground is probably located on the wrong side of your work surface. Welding projections are pieces of red burning metal flying from the point of contact. Although they can be relatively easy to remove, too many of them can ruin your weld and the aesthetic of your project.

Where you plug your ground matters because the direction in which the current travels. Any type of stud welding system creates an arc. When using an arc welder, either with rods or with studs loaded with flux, you have to weld in the opposite direction from the ground. When you are welding toward the ground, you get a lot of projections because you're going against the source of current. Relocating the ground on the other side of your work surface should fix that problem. Keep in mind that some types of studs may require you to weld toward the ground, so read carefully the package before using them.

Even if you are able to weld without causing any projection, never weld without your safety jacket. Welding arcs create ultraviolet and infrared radiation, which are known to cause skin cancer. Bare skin exposed under a welding arc will burn the same way as it does under the sunlight.

Wrong Polarity

If these issues below are the problems you get, your machine is probably running on the wrong polarity.

  • Bad penetration
  • High amount of splatter
  • Weak control of your arc

A stud welding machine works in DC (direct current) and uses an arc stud to weld. The polarity dictates which direction the electric current travels. Aluminum welding usually requires a direct current electrode positive, also called reverse polarity, while steel welding typically requires a direct current electrode negative, also known as straight polarity. 

The labeling package of your studs indicates which polarity they require. Although some models have a switch to change the polarity, some stud welding machines will need you to manually switch some cables. If your electrode holder is plugged into the "+" terminal, and the ground on the "-" terminal, you are on reverse polarity. If you switch these two cables, you will get a straight polarity. 

Wrong gas pressure

Some stud welding systems utilize gas. A mix of acetylene and oxygen is typically used, but argon and helium are also sometime utilized. The required proportion and pressure vary according to the thickness of the base metal.

With the wrong gas flow, you may get some of these issues:

  • Stud creates hole in the base metal: gas pressure too high
  • Stud creates black oxidation spots on the base metal: gas pressure too low
  • Stud is not melting at all: the part connecting the gas tank to the welder may be defective
  • Tiny holes poking through the weld: leak coming from from the gas tank, check the seal joint.

When using a gas arc stud welding machine, there is no flux or ferrule involve. Because it makes it easier to automate, robotic industries often rely on these welders. However, don't expect a gas stud welder to have as good a penetration as a drawn arc or a short arc welder.

Problem still not fixed?

If these tips aren't troubleshooting the problem, please do not pull your welder apart. Removing screws and opening the welder shell will likely cause serious injury or make the problem worse. Don't be afraid to give a call to a qualified technician who specializes in stud welder repair. Contact a company like Northland Fastening Systems for more information.