Gas actually is better, especially where high precision is required. It is more recommended to be used when welding high pressure containers, as It gives out less discontinuities, like porosity, inclusions, etc. only that is more expensive than the electric.
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Michael Erwin Duro , Technical Manager , MAKANA Industries and Services Co. Ltd
OAW is an obsolete process that is almost never used. It produces welds of inferior quality. Professionals use arc welding methods for just about everything.
Advantages of OAW - doesn't require a source of electricity so it's very portable.(however gas engine driven welder-generators for arc welding are standard equipment these days.)
Disadvantages- gases are expensive, extremely flammable, and dangerous. Very slow production rate, excessive heat input causing warping of material and large heat-affected zone, produces welds of low quality. Equipment is difficult to use. Not practical for steels >3/16" thickness. Can only used for steel or copper alloys.
Advantages of arc welding methods- produces welds that are stronger, much faster, much lower heat input, and have better quality than OAW in every sense. Can weld metals of any thickness, (TIG/GTAW is useful for very thin sheet metal) Can weld most metals, steel, stainless, nickel, copper, aluminum, etc.
Disadvantages- requires a source of electricity or a purpose-built generator. Produces intense light, radiant heat, and ultraviolet rays making special protective equipment necessary. Typically produces lots of sparks and spatter which can cause a fire hazard. Electric current can be dangerous if standing water is present.
