Tools Of The Trade

Early portable generator, circa 1929. (photo courtesy of Rexarc)   Crimping tool, 1961 (photo courtesy of Western Enterprises)

For millennia, humans have sought ways to join metal for both practical and aesthetic purposes. Ancient Egyptians heated iron ore in a charcoal fire and hammered it to weld it together, a process known as “pressure welding.” Evidence of gold brazing dates back to at least A.D. 60. However, welding as it commonly is practiced today—and the equipment we've come to take for granted—dates to much more recent times.

Some of the most important developments in the history of welding took place in the 19th century. In 1801, Sir Humphrey Davy was the first to produce an arc between two electrodes using a battery, while in 1836, Edmund Davy discovered acetylene. Both discoveries would have long-lasting effects in the field of welding.

The electric arc wasn't put to practical use until the mid-19th century with the invention of the electric generator and, in 1881, the introduction of carbon-arc street lamps. However, a major step in welding technology occurred in 1885 when Russians Nikolai Benardos and Stanislav Olszewski were granted a British patent for an electric arc welder with a carbon electrode. The welder was named “Electrogefest” or “Electrohephaestus,” after Hephaestus, the Greek god of fire and patron of all craftspeople, especially those working with metals. Russian and American patents soon followed in 1886 and 1887. Benardos and Olszewski are considered the inventors of the modern welding apparatus.

Significant inroads were made in arc welding technology in the last two decades of the nineteenth century, including the use of a metal electrode instead of carbon, as well as the 1887 introduction of an insulated handle that permitted manual operation. In 1890, American C. L. Coffin secured a patent for electrical arc welding with a metal rod.

The end of the 19th century also saw advancements in the field of oxyacetylene welding. In 1887, the first “blowpipe” or torch using acetylene and liquefied air or oxygen was developed, and in 1895 a machine for liquid air generation was placed in operation. In 1900, the first oxyacetylene torch suitable for use with low-pressure acetylene was introduced.

The arc welding industry in the United States began to take off in the early decades of the 20th century. In 1911, The Lincoln Electric Company introduced the world's first variable voltage, single operator, portable DC welding machine. Around the same time, the covered or coated electrode was invented by Oscar Kjellberg and ESAB, which paved the way for the research and development of flux coated electrodes. By 1930, covered electrodes were widely used.

The 1920s saw research into techniques to shield the arc and weld area using externally applied gases. In 1926, H.M. Hobart and P.K. Devers applied for patents for their research involving welding atmospheres of argon and helium. Their process of arc welding utilizing gas supplied around the arc was a forerunner of the gas tungsten arc welding (GTAW or TIG) process, which would be perfected in 1941. Hobart and Devers's process of welding with a concentric nozzle and with the electrode being fed as a wire through the nozzle was the forerunner of the gas metal arc welding (GMAW or MIG) process, which would be perfected in 1948.

In the 1920s, most electric arc welding was done with large, expensive, three-phase motor generators with DC output. Three-phase power was very limited and usually only available in big cities. In 1929, Niels Miller created a simple, non-rotating arc welder able to run on the AC electricity available in rural areas, and in 1936, engineer Al Mulder invented the world's first high frequency-stabilized AC industrial welder, which made AC welding practical for use in factories and construction. By the early 1950s, DC welders came onto the market that used a selenium rectifier to convert AC power into DC weld output in order to achieve a smoother arc.

The 1950s also saw the debut of the flux-cored arc welding process, the invention of plasma arc welding and the introduction of electron beam welding. Each of these has found use in a variety of fields, as have more recent developments such as laser welding, one of the newest welding processes. A major technological advancement in the 1980s was the introduction of inverter power sources, which are smaller, quieter and more responsive than conventional welders.

As the welding industry continues to evolve, so too does the equipment welding professionals employ. Ancient civilizations could only dream of the tools now available for welding processes, and with the technology being invented every day, it is certain that the tools of tomorrow will continue to astonish.