Since most structures are fabricated inside a shop, where compressed air or inert gas are readily
available, the first-mentioned welder (see A above) has proved to be an adequate production tool. Where
there is no access to a high pressure air source, such as for outdoor repair jobs, a compressor unit can
be added (see B above). All metal parts of this welder are made of stainless steel because this material
withstands corrosive fumes, resists moisture, and is durable.