Ensure electrical connection leads are in good condition and tight prior to use. They should be protected to prevent accidental damage from hangar traffic. Make sure you have adequate ventilation. GTAW uses inert gases during the process, if it is used in an enclosed area it can displace breathing air and can be hazardous without proper ventilation. In addition, ozone is produced during the welding process. The amount of ozone produced varies with type of electrode used, amperage, and argon flow. In poorly ventilated areas, ozone levels can increase to harmful levels. Whenever possible, draw fumes and contaminated air away when welding. Flammable materials should not be carried in clothing pockets. Shielding curtains should be placed around all jobs so that workers in adjacent are not exposed to the welding arcs. Shielding Gas In GTAW, the gas used to shield the welding arc and hot metals is an inert gas. Inert gases are gases whose atomic structures do not allow them to react with metals or other gases. Argon, helium, or an argon-helium mixture is used as the inert gas in GTAW. Argon is a relatively heavy gas. It has several benefits when used in GTAW. It requires a lower arc voltage than other shielding gases for a given arc length and current used (ideal for thin metal welding). It also provides easier arc starting. Its heavier weight as compared to helium provides for good shielding with lower flow rates. In contrast to helium is the lightest of the inert gases. Because of its light weight, about two to three times more helium is needed as compared to argon to shield the weld area. Despite this, helium has an advantage over argon in that it can be used with greater arc voltages. Because of this, helium is preferred when working with thick metal sections. Another difference in the two gases is their cleaning ability. Both helium and argon allow for good cleaning action when using DC. However, when using AC,
Ensure electrical connection leads are in good condition and tight prior to use. They should be protected to prevent accidental damage from hangar traffic. Make sure you have adequate ventilation. GTAW uses inert gases during the process, if it is used in an enclosed area it can displace breathing air and can be hazardous without proper ventilation. In addition, ozone is produced during the welding process. The amount of ozone produced varies with type of electrode used, amperage, and argon flow. In poorly ventilated areas, ozone levels can increase to harmful levels. Whenever possible, draw fumes and contaminated air away when welding. Flammable materials should not be carried in clothing pockets. Shielding curtains should be placed around all jobs so that workers in adjacent are not exposed to the welding arcs. Shielding Gas In GTAW, the gas used to shield the welding arc and hot metals is an inert gas. Inert gases are gases whose atomic structures do not allow them to react with metals or other gases. Argon, helium, or an argon-helium mixture is used as the inert gas in GTAW. Argon is a relatively heavy gas. It has several benefits when used in GTAW. It requires a lower arc voltage than other shielding gases for a given arc length and current used (ideal for thin metal welding). It also provides easier arc starting. Its heavier weight as compared to helium provides for good shielding with lower flow rates. In contrast to helium is the lightest of the inert gases. Because of its light weight, about two to three times more helium is needed as compared to argon to shield the weld area. Despite this, helium has an advantage over argon in that it can be used with greater arc voltages. Because of this, helium is preferred when working with thick metal sections. Another difference in the two gases is their cleaning ability. Both helium and argon allow for good cleaning action when using DC. However, when using AC,
the_science_and_math_of_arc_welding.docx