If you’re wondering how to weld aluminum, it’s important to know that there are several welding processes that can be used:

• GTAW/TIG welding

• GMAW/MIG welding

GTAW/TIG

Gas tungsten arc welding (GTAW) is also known as tungsten inert gas (TIG) welding. TIG welding aluminum is one of the most popular welding processes chosen for this material. This welding technique is often used by automotive enthusiasts and welders for professional racing teams.

GTAW requires constant current equipment with AC (alternating current) capabilities using 100 percent argon as a shielding gas. It does not require mechanical wire feeding, which has the potential to create feeding issues.

Rather, the welder will feed the filler material into a puddle. This process is also very clean, as the alternating current cleans the oxidized layer off the aluminum as it welds. It also prevents aluminum from being contaminated throughout the process.

Tips for TIG welding:

• Pick the right tungsten electrode or rod—the best choice for aluminum is typically a pure tungsten rod.

• Take the time to prepare your aluminum by cleaning and preheating it.

• Ensure there is not too much argon flow at the torch, which can cause an irregular arc.

• To prevent warping, use a heat sink.

• When welding, keep the proper aluminum filler electrode or rod free of contaminants and melt it with the base material to create a constant welding puddle.

GMAW/MIG

Gas metal arc welding (GMAW) is commonly referred to as metal inert gas (MIG) welding. MIG welding aluminum is another common method used for this material.

This type of welding typically has faster travel speeds and higher deposition rates than TIG welding, affecting the weld quality. However, it does utilize a mechanical wire feeding system, which means the welder may have to use a spool gun or push-pull gun to make wire feeding possible.

Additionally, to combat the risk of aluminum becoming porous, the base material and filler rod must be clean, free of moisture and have excellent shielding gas coverage, typically pure argon content.

Tips for MIG welding:

• Prepare your push-pull wire feed.

• Clean your aluminum, remove any oxide and file the edges that will be joined.

• Avoid pulling while welding—instead, push at a 10-degree to 15-degree angle.

• Use multiple-pass straight beads to improve the overall appearance of the weld and help to avoid defects.

• Use a heat sink, which will absorb extra heat and allow you to weld more slowly.