that's what Linde Union Carbide branded it after Russell Meredith came up with the refined process which had already been around for quite some time but needed more improvements to be a reliable process and to be used with Aluminum & Magnesium back in the forties and it was first used in building Dr. John K, Northrop's XP-56 airplane body for Lockheed Aircraft... Gas tungsten arc welding (GTAW) had its beginnings from an idea by C.L. Coffin to weld in a nonoxidizing gas atmosphere, which he patented in 1890. The concept was further refined in the late 1920s by H.M.Hobart, who used helium for shielding, and P.K. Devers, who used argon. This process was ideal for welding magnesium and also for welding stainless and aluminum. It was perfected in 1941, patented by Meredith, and named Heliarc® welding. It was later licensed to Linde Air Products which was a division of Union Carbide, where the water-cooled torch was developed also.
C. L. Coffin had the idea of welding in an inert gas atmosphere in 1890, but even in the early 20th century, welding non-ferrous materials such as aluminum and magnesium remained difficult because these metals react rapidly with the air and result in porous, dross-filled, welds.[2] Processes using flux-covered electrodes did not satisfactorily protect the weld area from contamination. To solve the problem, bottled inert gases were used in the beginning of the 1930s. A few years later, a direct current, gas-shielded welding process emerged in the aircraft industry for welding magnesium.[3]
Russel Meredith of Northrop Aircraft perfected the process in 1941.[4] Meredith named the process Heliarc because it used a tungsten electrode arc and helium as a shielding gas, but it is often referred to as tungsten inert gas welding (TIG); in parts of the world where tungsten is called wolfram, it is known as WIG. The official American Welding Society term is gas tungsten arc welding (GTAW). Linde Air Products, a Division of Union Carbide Corporation, purchased US patent 2,274,631 and name from Northrup and developed the process. Linde, along with others, developed a wide range of air-cooled and water-cooled torches, gas lenses to improve shielding and other accessories that increased the use of the process. Initially, the electrode overheated quickly and, despite tungsten's high melting temperature, particles of tungsten were transferred to the weld.[3] To address this problem, the polarity of the electrode was changed from positive to negative, but the change made it unsuitable for welding many non-ferrous materials. Finally, the development of alternating current units made it possible to stabilize the arc and produce high quality aluminum and magnesium welds.[3][5]
http://en.wikipedia.org/wiki/Gas_tungsten_arc_weldingRussell Meredith - Inventor of Gas Tungsten Arc Welding
Russell Meredith was born in 1901. His interest in welding began while he was a pipeliner for the Southern California Gas Company. Later, while working for Warner Brothers Studios in Hollywood he repaired cars that were banged up from movie chase scenes... In 1934 Russell joined Lockheed where he worked for 35 years. During that time he was assigned to figure out how to weld magnesium for Dr. John K. Northrup's XP-56 airplane body... In 1942, Meredith was issued US Patent 2274631 for the process originally named Heli-Arc welding and now known as Gas Tungsten Arc Welding.
http://weldinghistory.org/whfolder/biography/bio-meredith.htmlDevelopments continued during the following decades. Linde Air Products developed water-cooled torches that helped to prevent overheating when welding with high currents.[6] Additionally, during the 1950s, as the process continued to gain popularity, some users turned to carbon dioxide as an alternative to the more expensive welding atmospheres consisting of argon and helium. However, this proved unacceptable for welding aluminum and magnesium because it reduced weld quality, so it is rarely used with GTAW today.[7] The use of any shielding gas containing an oxygen compound, such as carbon dioxide, will quickly contaminate the tungsten electrode and should not be used with the TIG process.
In 1953, a new process based on GTAW was developed, called plasma arc welding. It affords greater control and improves weld quality by using a nozzle to focus the electric arc, but is largely limited to automated systems, whereas GTAW remains primarily a manual, hand-held method.[7] Development within the GTAW process has continued as well, and today a number of variations exist. Among the most popular are the pulsed-current, manual programmed, hot-wire, dabber, and increased penetration GTAW methods.
http://en.wikipedia.org/wiki/Gas_tungsten_arc_weldingHere's another cool site for the novice who's interested in learning some interesting history and facts surrounding TIG or GTA Welding:
http://www.netwelding.com/history_tig_welding.htmFinally, here's an article to read in an older version of Adobe .pdf reader (Don't worry, your up to date version will give you the option to use an older version) written by
Grant Ken Hicken, Sandia National Laboratory... It's not a direct link so you need to first copy & paste into your url bar up on top of the page to get to it:
ftp://63.174.97.22/pub/MARC_Records/V06/asmhba0001356.pdfI want this system for jewelry making & repairs and silver & any other precious metal repairs:
Review & Usage of Lampert's Pulse Arc Welders © Jeffrey Herman Society of American Silversmiths
Check this version of micro TIG or GTA welding:
Overview
As any silversmith knows, silver solder is the ideal material to use when joining sterling pieces by the traditional method of brazing. Sometimes I will receive an object which has been lead-soldered in the area in need of repair (or re-repair). Sometimes the joined area is not visually accessible, and I don't know if lead has been used.
In either case, I cannot use silver solder because the high temperature required will melt any lead in the joint and allow it to form its own alloy with the silver. Not pretty! And, using a low temperature tin/silver solder won't give me a sound joint or good silver color. For this reason, I had been exploring newer technologies for joining metals. I tested laser welders from a few manufacturers, but found that their compartments are too small for working on holloware. In addition, they are expensive to buy and notoriously expensive to repair, and the down-time for repairs can be substantial. I also tested the Mini Pulse III (an arc welder) from Aelectronic Bonding, which had too few welding power options and didn't allow me to get into tight spaces.
I tested a friend's Lampert PUK 2 pulse arc welder for a few months, and refined my technique to the point where I felt confident to purchase Lampert's PUK 3s Professional, which was developed to weld silver more successfully. I was so impressed that I soon purchased the PUK 3s Professional Plus which had a broader power range, additional impulse settings, and five programmable settings.
Since I use the PUK on a daily basis, it was only natural to upgrade again to Lampert's latest model: the PUK04, which has the following advances over the previous models I've owned. Features in bold were the most important to me:
• Touch-screen programming.
• Smaller footprint;
• Exclusive "soft start" pulse for even cleaner welds and less electrode tip embedment;
• Substantially less cracking when welding and using filler wire for an even stronger weld;
• Minimum impulse setting: .5 milliseconds – critical for ultra-thin metal (the PUK 3s Plus: 3ms);
• 33 programmable settings (the PUK 3s Plus: 5);
• Three LED intensity settings.
Advice on welding larger objects
Whether it be pulse arc or laser, welding isn't meant to substitute for brazing large objects. Welding long seams (e.g., on coffeepots or candlesticks) is more time-consuming than simply using the welder to tack a seam in preparation for brazing.
If attaching parts to large bearing surfaces (e.g., a large finial to a coffeepot cover), it's best to tack the part in place, then use the capillary action of torch-brazing to fill the void. Always consider the time it will take to weld or braze and the subsequent clean-up... I want one but I don't have $5-1/2 K dollars to purchase!
There's a whole bunch more in the link below.
http://www.silversmithing.com/puk.htm#OverviewI still want one!!! Well that's it for now... I gotta rest for pulmonary rehab tomorrow and tolerate a so-called respiratory therapist coming from my so-called oxygen supplier which ought to be so much fun! Enjoy the reading!
Respectfully,
Henry
