TIG Welding Aluminum Tips and techniques
TIG welding aluminum can be challenging due to its low melting point, high thermal conductivity, and tendency to form oxide layers on the surface. Here are some tips and techniques for TIG welding aluminum:
Clean the surface: Before welding, it is important to thoroughly clean the surface of the aluminum to remove any dirt, grease, or oxide layers. Use a stainless steel brush or a wire wheel to clean the surface, and then wipe it down with acetone or a degreaser to ensure a clean surface.
Use the correct tungsten electrode: For welding aluminum, it is recommended to use a pure tungsten electrode or a tungsten electrode alloyed with thorium or zirconium. The diameter of the tungsten electrode should also be larger than for welding steel, typically around 3/32” to 1/8”.
Use AC power: TIG welding aluminum requires the use of alternating current (AC) rather than direct current (DC). AC power helps to clean the oxide layer from the surface of the aluminum, allowing for a stronger weld.
Use a high frequency start: A high frequency start can help to initiate the welding arc and prevent the tungsten electrode from sticking to the aluminum surface. Make sure to keep the torch steady during the start-up process to prevent any arcing or damage to the material.
Use a push technique: When welding aluminum, it is generally recommended to use a push technique rather than a pull technique. This helps to prevent the oxide layer from being dragged into the weld and creating defects.
Use a lower amperage: Aluminum has a lower melting point than steel, so it is important to use a lower amperage when welding to avoid overheating and melting the material. Use a lower amperage and a slower travel speed to allow the material to cool between welds.
Use a shielding gas: A shielding gas, such as argon or helium, is necessary for TIG welding aluminum to prevent contamination and oxidation of the weld. Use a higher flow rate than for steel, typically around 20 to 30 cubic feet per hour (CFH).
By following these tips and techniques, TIG welding aluminum can be a successful and rewarding process. With practice and patience, you can create strong and beautiful welds on aluminum materials.