How does gas welding use acetylene and oxygen to create a weld?

Gas welding, specifically oxyacetylene welding, is a fusion process that utilizes the combustion of acetylene in oxygen to generate an intense, closely controlled flame.1

When burned in a properly designed torch, this mixture achieves temperatures of approximately 3,300 °C to 3,500 °C, which is sufficient to melt the base metal at the joint. During the process, a cold filler wire is typically added to the molten pool to complete the weld.123

To ensure high-quality results, operators generally maintain a neutral or reducing flame to prevent oxide contamination of the base metal. Additionally, fluxes are often employed to further protect the joint from oxidation. While once a primary industrial method for fabricating steel components, gas welding is now largely reserved for specialized sheet fabrication and artistic applications due to its relatively slow welding speeds compared to modern arc welding techniques.12