How to Weld Aluminum - Learn To Weld Aluminum

The tungsten must be ground properly prior to fitting it into the torch. Chancy said to always grind your tungsten lengthwise as shown. Otherwise, the arc will jump off the tip in an erratic pattern.

You may have heard you should ball the tip of the tungsten when welding aluminum, but a ball actually forms as you weld, so it's best to grind your electrode to a point that's about two times as long as its diameter. Welding in the AC mode puts a lot of heat into the tungsten, causing the tip to melt slightly forming the ball at the end of the electrode.

Here's the unassembled TIG torch from our Miller Diversion 165 TIG welder. Note the newer-style thumb control on the handle, which takes the place of the traditional foot pedal to control the output of the torch. From left to right, the parts are: a gas shielding cup, a tungsten electrode (the yellow tip means 1 percent thoriated tungsten, good for welding mild steel), a collet body, a collet (copper part the tungsten is slipped through) torch body, and an endcap.

We recommend using a gas lens, the large copper and mesh piece installed in the torch. It replaces the collet body and does a better job of diffusing the shielding gas that flows out of the tip of the torch, blanketing the weld bead with a more even layer of argon. Using a gas lens also requires using a larger shielding cup.

Choose the proper tungsten and filler rod diameter. We will be welding 1/8-inch sheet aluminum, so we selected a 3/32-inch tungsten and 1/8-inch rod. The general guidelines are to use a tungsten that is a smaller diameter than the parts you're welding. Likewise, the filler rod should be about the same diameter as what you're welding.

The importance of a good ground cannot be overstressed. Make sure you have a good surface to clamp the ground strap to or a clean tabletop if you're using a metal workbench as the ground. Like bad grounds in a car, you want to make sure all the resistance in the welding process is in the arc, not in your connections.