Aluminum TIG Welding

Aluminum TIG Welding Tips for Beginners

Fred Bahnson 

Mastering TIG welding aluminum can be challenging for beginners. However, with practice and following some essential guidelines, you can achieve the desired results. In this article, we will explore four steps to help you improve your aluminum TIG welding skills.

Step 1: Hand and Torch Placement

Proper hand and torch placement are crucial for successful TIG welding. Aluminum acts as a heat sink, quickly dissipating heat from the weld area. Therefore, controlling the weld puddle is essential. Follow these guidelines:

  1. Hold the torch with the base of your hand (from your wrist to the tip of your pinky finger) braced against the table.
  2. Maintain a steady, forward-moving torch position with a slight backward tilt of 5 to 15 degrees.
  3. Keep a close distance between the tungsten and the workpiece, typically equal to the tungsten diameter up to about 1/4 inch. If the tungsten is too far from the workpiece, the arc will spread too wide, overheating the piece and compromising puddle control.

Step 2: Coordinate Movement and Filler Deposition

Developing coordinated hand and torch movement is crucial for achieving smooth welds. Practice the following techniques without striking an arc:

  1. Apply light pressure to your hand and firmly grip the welding torch. Slide your hand across the welding table in an even and steady motion. Avoid moving only your fingers, as it limits your welding range. This practice helps you calibrate hand and torch movement and maintain the right distance between the tungsten and the workpiece.
  2. Filler metal deposition should occur ahead of the TIG torch as you push forward. The torch and filler rod should be approximately 90 degrees to each other. Always push the torch and introduce the filler metal on the leading edge of the puddle. One hand should slide smoothly, while the other hand dabs the filler metal. Practice this technique without striking an arc.

Developing independent hand movement is crucial to avoid contaminating the filler metal with the tungsten. Practice these techniques until each hand performs its task independently.

Step 3: Practice Puddle Control

Before introducing filler metal, practice establishing and controlling the weld puddle. Without adding filler metal, use the guidelines discussed in Step 1 to establish the puddle and move along the workpiece. Take note of the following:

  1. Aluminum quickly heats up due to its heat sink properties. Monitor the puddle width as you move along to ensure consistency. If the puddle becomes too hot, reduce the foot pedal pressure to maintain a consistent width.
  2. When reaching the edge of the workpiece, where less aluminum absorbs heat, the puddle washes out faster. Reduce the pedal pressure to maintain puddle control. However, be cautious not to apply too little heat, as it can cause the puddle to disappear and result in an erratic arc without proper fusion.

Practicing puddle control without filler metal helps you maintain speed, distance, and puddle width. As the piece heats up quickly, set it aside and continue with another one to avoid losing control of the puddle.

Step 4: Introduce Filler Metal to the Puddle

Once you have mastered the previous steps, it’s time to introduce filler metal to the puddle. Follow these guidelines:

  1. Consistency is key when adding filler metal. Start by dabbing and moving the filler metal smoothly. Avoid excessive torch movements, as the dabbing motion creates the desired bead profile.
  2. Establish the puddle and add filler metal to the edge of the puddle. Maintain a consistent rhythm, combined with steady torch movement and puddle control. With practice, you will be able to lay proper weld beads on aluminum.

Step 5: Setting Weld Parameters and Understanding Advanced Features

Some TIG machines offer advanced features that allow you to fine-tune your welding arc. These adjustments can better match joint design and achieve the desired appearance of the weld bead. Consider the following:

  1. Balance: The balance function controls the cleaning or etching of the oxide layer on aluminum. Lower balance numbers provide more cleaning, while higher numbers reduce the cleaning effect. Adjust this setting based on the joint design, oxide layer thickness, or desired weld bead appearance.
  2. Frequency: The frequency function focuses the arc and is useful for tailoring the arc to the joint design. Lower frequency settings result in a wider, lazier arc, while higher settings create a tighter, more focused arc. Higher frequencies are suitable for precise welding or tight areas, while lower frequencies are ideal for butt joints or areas requiring additional weld material.

Practice adjusting these settings to understand how they can be tailored to your specific needs and preferences.

By taking it slow and dedicating time to practice, you can reduce aluminum scrap and enhance your TIG welding skills.