Portable Spot Welders

Spot welding is a type of resistance welding process used to join two or more metal pieces together at specific points.

It works by passing an electric current through the metal pieces to be joined, creating resistance and generating heat at the point of contact. This heat causes the metal to melt and fuse together, forming a “spot” weld.

Read all about the spot welding process in our guide.

Spot welding is commonly used in the automotive industry for joining sheet metal components in vehicle bodies, as well as in the manufacturing of appliances, electronics, and various metal fabrication applications.

It offers advantages such as high speed, efficiency, and consistency, making it a popular choice for mass production applications. It is also a very cost effective method, requiring no additional materials to complete the weld, like arc welding processes.

Using a spot welder can vary between different machines, however the below can be used as a simple guide to get you started:

• Setting up the spot welder: Adjust the welding parameters on the spot welder, including welding current, welding time, and electrode pressure, based on the material thickness, type of metal, and desired weld quality. Consult the manual or welding procedure specifications for recommended settings. Make sure the spot welder is properly grounded to prevent electrical hazards.
• Positioning the electrodes: Position the copper electrodes or welding arms on either side of the metal sheets to be welded, ensuring that they make firm contact with the material surface. Apply sufficient pressure to hold the workpieces firmly together during the welding process. Some spot welders have adjustable pressure settings that allow you to control the electrode force.
• Performing the weld: Press the welding pedal or trigger to initiate the welding process. This activates the spot welder, passing an electric current through the metal pieces and generating heat at the electrodes/contact points. Hold the pedal or trigger for the duration of the welding cycle, ranging from a fraction of a second to a few seconds, depending on the welding parameters and material thickness.

As with any welding process, practice and experience will improve your proficiency in using a spot welder effectively.

Spot welding aluminum requires specific techniques and equipment due to the unique properties of aluminum, such as its high thermal conductivity and low melting point compared to steel. Set yourself up for success by:

• Selecting the right equipment (it will need to have a high current rating, as well as the correct parameter settings)
• Preparing and cleaning the aluminium sheets thoroughly
• Choosing copper electrodes or tips, preferred becuase they resist sticking to aluminium and have good thermal conductivity
• Set the welding parameters on the machine depending on the application and material, reference the manufacturer guidelines for these
• Avoid excessive pressure when clamping the aluminium sheets during the welding process to avoid damage
• Monitor the welding process and inspect after completion to ensure proper fusion and formation of the weld nugget

Spot welding batteries requires specialised equipment and techniques due to the sensitivity of battery cells, as well as the need to ensure a reliable and safe connection.

Choose a spot welding machine for battery applications, make sure you clean the surface of the battery cells with a wire brush, sandpaper or safe chemicals to ensure a proper fusion, without damaging the battery cell. You will also need to set the right parameters for the application, as well as choose the right electrodes (copper being preferrred due to greater thermal conductivity).

Depending on the application and requirements, you may need to perform additional post-weld treatments such as testing the weld strength, applying insulating materials, or securing the welded connection with adhesive or heat shrink tubing.