Spot Welding for Home and Commercial Use

Spot welding is ideal for sheet metals, used widely in the automotive industry, steel pail production, even braces used in orthodontics. Sheets that are between .5 and 3 mm are ideal, as thicker metals can pose problems as it’s often difficult to heat in a single spot.

When it comes to welding equipment, and spot welders are the most common form, probably because they are easy and fast to use. It’s high speed forms a weld in a fraction of a second, which makes spot welding ideal for assembly lines.

This makes spot welding easily adaptable to automation. More and more manufacturing lines are using robotics in the interest of efficiency, consistency and speed. A large number of materials can be welded very quickly to the level of consistent perfection that’s demanded in the product manufacturing. You can rely on the same weld every time, insuring the uniformity of production.

Two shaped copper alloy electrodes concentrate the force of the welding current between the two objects being joined. A small “spot” results, and is quickly heated to its melting point, forming a small nugget of welding material after the current has been removed. Heat is controlled according to the strength of application and the length of which the current is applied.

Because spot welding is relatively easy to learn, it’s often used by artists and hobbyists, and is common in many home garages or studios.

Spot welding can also be done on aluminum, although as much as a 3 times higher thermal conductivity is required. This will require larger and more expensive welding equipment and spot welders.

As with any type of welding, safety is essential. Although it is a relatively easy weld to learn, spot welding is dangerous and requires proper safety equipment. It uses large amounts of current and heat. Electrodes must be clamped tightly. Wear eye protection to protect both against sparks and high amounts of ultraviolet light. Hands should also be protected, as the objects can become very hot. Spot welding should always be done in as controlled an environment as possible.

Unfortunately, the spot welding process tends to harden the metal, especially thick metals, causing it to wrap and reduce its material fatigue strength. This can lead to internal cracking, surface cracks and a bad appearance, as well as compromising the integrity of the metal. For most applications, however, spot welding works just fine and is easy to do, which is probably why it is so common.