What typically does an arc welder use to create a weld?

An arc welder primarily uses high voltage electricity to create a weld. This process involves generating an electric arc between an electrode and the workpiece, which produces a significant amount of heat. This heat is sufficient to melt the metal at the joint, allowing for the materials to fuse together as they cool.

The use of high voltage is critical as it establishes the arc required for the welding process. The intensity of the heat generated directly correlates with the voltage and current levels, making it essential for achieving proper penetration and bonding of the materials being welded.

In contrast, the other options do not accurately describe the functioning of an arc welder. A torch relies on heat from combustion, which is not how arc welding operates. Chemical reactions pertain more to processes like soldering or certain types of welding like thermite welding. Joint compression is not a method used for creating a weld in arc welding; rather, it may pertain to mechanical fastening methods or specific types of joining processes. Therefore, the use of high voltage electricity is the defining characteristic of arc welding techniques.