Tips Of TIG Welding
Since tungsten welding operates at high temperatures, ideal metals are those that have a low melting point. This includes:
· Aluminum: use on AC output and high-frequency setting. Keep the tungsten from touching the piece being welded to avoid contamination. Conducts heat. Clean aluminum with a wire brush (even if it looks clean) to remove aluminum oxide. Use high heat settings to increase welding speed.
· Magnesium: similar properties to aluminum
· Copper alloys (brass, bronze, copper nickel, copper aluminum, silicon): use DC current with electrode negative
· Stainless steel: requires the use of a filler rod with high chrome component. Use gas lenses for better gas coverage of weld. Keep gas flow at 15 to 20 cfh.
· Mild steel: use rods with deoxidizers. The tungsten electrode should be 2% thoriated. Clean the steel before welding.
If TIG weld cracking occurs preheat the metal to 400 degrees Fahrenheit. This helps with the contraction and expansion of the metals when welding.
· Operate with safety in mind
· Ensure that the argon or helium gas supply has low moisture
· Use filler rods that are clean and keep the welding area dry
· Tungsten electrode selection and parameters for welds are guidelines not absolute
· Follow the welding safety precautions provided by all material providers. Since tungsten has some radioactivity, if grinding wear a respirator
· Bigger rods are easier to handle
· The tungsten electrode should be the smallest needed to do the job
· Keep the rod and torch at different angles
· Wind drafts will reduce the effectiveness of shielding argon or helium gas resulting in pinholes in weld
· Higher amps require larger orifice
· If the tungsten moves or wiggles during the welding process it indicates that the tungsten is near its capacity. Use the balance dig dial moved to the penetration side.