A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?

A mixture of oxygen and ethyne is burnt for welding instead of mixture of ethyne and air because the production of heat is very important for welding metals. When oxygen and ethyne are burnt, it burns completely and produces a higher temperature than air and ethyne. Oxygen and ethyne produce very hot blue flame but the mixture of air and ethyne gives out a sooty flame which means that there are unburnt particles resulting in lesser heat.