Why Use The Gap Capacitor Discharge (CD) Stud Welding Method?

If you are welding studs with smaller diameters to thinner materials, capacitor discharge stud welding may help you get the job done more quickly.

Capacitor discharge, or CD, stud welding, uses a capacitor storage system that can create a very fast electrical discharge instead of relying on an AC or DC power source. That discharge rapidly heats and melts the materials, which are pushed together with a stud welding gun to make a weld with high integrity. You don't need flux or ferrules for the weld.

The Gap Method of CD Stud Welding

There are two ways that a capacitor discharge welding system can work. 

  1. Contact CD Stud Welding. The fastener or stud is positioned directly on the metal that it will be welded to before the electrical discharge is dispersed.
  2. Gap CD Stud Welding. This is usually a slightly faster method, where the stud is positioned slightly above the metal and accelerated into it as the electrical discharge begins. 

The difference between the two is the speed with which the weld occurs; both methods are fast, but the acceleration of the stud toward the metal in the gap method means that the weld happens slightly faster. This can be advantageous when you're welding non-ferrous alloys or aluminum which can conduct heat better than other metals. These metals can pull heat away from the stud so quickly that you aren't able to produce a good weld. By using the gap method of CD stud welding, you can see better results than you might from other techniques.

Benefits of Gap CD Stud Welding

Gap CD stud welding happens fast, and there are additional benefits to this besides a better weld on some types of metals.

  • Stronger weld with lightweight materials. It can be challenging to weld very thin materials. Gap CD stud welding lets you create a strong bond even with very thin sheets of metal.
  • Nicer appearance. CD stud welding can be done from one side, and there are no unsightly dimples on the opposite side. As an added benefit, you can even paint the opposite side before welding because it won't be damaged or even dented.
  • Higher productivity. Because the weld happens quickly, you can do more in less time. You also avoid doing any drilling or riveting with this process.
  • Easier fabrication. Need to duplicate a part that's an odd size? You can quickly do several welds to fabricate the same shape.

Because of these benefits, CD stud welding is often used for making jewelry, light hardware, small appliances or cookware and products with electronic or electrical components.

For more information, contact Northland Fastening Systems or a similar company.