TIG Welding Aluminum for Beginners

Step 1: Key to Puddle Control: Hand & Torch Placement

Beginning TIG welders unintentionally make a lot scrap. For example, you may feel a need to strike an arc on a piece of aluminum before ever practicing basic hand placement and control. Don’t, as this is a waste of good aluminum. The first step to working with aluminum is to master positioning of the torch and hand.
Hold the torch by bracing it with the base of your hand (from your wrist to the tip of your pinky finger) flat against the table. Keep it in a steady, forward-moving position with a slight (5- to 15 -degree) backward tilt to the torch. (Figure 1).



Figure 1: Keep the torch in a forward-moving position with a slight 5- to 15-degree backward tilt.
Keep a close distance from the tungsten to the workpiece (typically equal to the diameter of the tungsten up to about ¼”). If you pull the tungsten too far away from the workpiece, the arc spreads out too wide and overheats the piece and you lose puddle control (more specifics on this topic to come in Step 3). Working with aluminum is all about puddle control and fighting the fact that it acts like a huge heat sink and rapidly transfers heat away from the weld area ( this is why steel is much more forgiving: the heat stays more localized, which in turn makes it easier to control the puddle).

Step 2: Coordinating Movement and Filler Deposition

Without striking an arc, work on the flow of your hand and torch movement. Practice with gloves on as you would in a normal welding situation. Keep light pressure on your hand, a firm grip of the welding torch and slide your hand across the welding table in an even, steady motion. If you don’t move your hand and you just move your fingers, you’ve become a one- or two-inch welder, and there aren’t many applications where that is useful. This practice helps you “calibrate” hand/torch movement and the distance of the tungsten to the workpiece without creating any scrap.

Filler metal deposition takes place ahead of the TIG torch as you push forward. The torch and the filler rod should roughly be in a 90-degree configuration to each other (Figure 2). Always push a torch—never drag it­—and always introduce the filler metal on the leading edge of the puddle. One hand is smooth and steady as it slides, while the other hand dabs the filler metal. Practice this without striking an arc.



Figure 2: The torch and the filler rod should roughly be in a 90-degree configuration to each other.
Most beginners have issues, at first, getting their hands working independently. They usually end up moving both hands at the same time: As they attempt to dab the filler metal, the tungsten dips too, which usually results in touching the filler metal to the tungsten and contaminating. Disconnect your hands and brain so that each hand performs its task independently. When you’ve mastered these movements, you’re ready to strike an arc.

Step 3: Forming and Controlling the Puddle

As discussed in Step 1, hold the torch by bracing it with the base of your hand (from your wrist to the tip of your pinky finger) flat against the table. Keep it in a steady, forward-moving position with a slight backward tilt (5- to 15 -degree) to the torch. Keep a close distance from the tungsten to the workpiece (typically equal to the diameter of the tungsten up to about ¼ in.).

Without adding any filler metal, establish the puddle and walk it down the piece. Aluminum is a heat sink and gets hot very fast. It’s like driving a car downhill: it keeps picking up speed as it gets hotter and hotter. Hence, it’s always important to monitor the puddle as you move along to keep the puddle width consistent. If it gets too hot, ease up on the foot pedal to maintain a consistent width . When you get to the edge of the workpiece, where there is less alumin um to absorb heat, the workpiece gets hot very quickly and the puddle washes out much faster. It’s important to ease up on the pedal to maintain puddle control. However, if you don’t put enough heat into the puddle, the puddle will disappear, the arc will become erratic, and you’ll do nothing more than etch the aluminum.

The following sequence of photos shows how speed and heat affect the puddle:



Figure 3: Proper puddle width, maintaining speed and distance between the tungsten
and the workpiece.



Figure 4: Moving the torch too quickly along the piece causes you to lose puddle control. Slow down while maintaining heat input.



Figure 5: Slowing down torch speed too much and adding too much heat to the puddle causes problems related to excess heat input, as seen in the weld here.



Figure 6: Proper speed, but adding too much heat to the puddle causes you to lose control of the puddle, as seen here. Find the balance between speed and heat input.



Figure 7: Proper torch speed, but not enough heat put into workpiece causes the puddle to disappear.
Lay down a puddle like this without filler metal numerous times to practice maintaining speed, distance and the puddle width. Because the piece gets hot so quickly, set it aside and pick up another one before continuing . The hotter the piece gets, the more out-of-control the puddle becomes—why make training more difficult?

Step 4: Introduce Filler Metal to the Puddle

As discussed in Step 2, filler metal deposition takes place ahead of the TIG torch as you push forward. The torch and the filler rod should roughly be in a 90-degree configuration to each other (Figure 2). Always push a torch—never drag it­—and always introduce the filler metal on the leading edge of the puddle. One hand is smooth and steady as it slides, while the other hand dabs the filler metal.

The key to adding filler metal to the puddle is consistency. Start introducing the filler metal with a dab and move motion. There is no need for excessive torch movements as the dabbing of the filler metal creates the bead profile. Establish the puddle and add filler metal to the edge of the puddle. As you establish the movement, you can establish your rhythm. As long as you maintain a consistent rhythm combined with steady torch movement and puddle control, you’ll be laying a proper weld bead on aluminum in no time—as long as you keep practicing.

Courtery of Miller Electric MFG Co.
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