What do welders need to know before striking the arc? Artem Komarov noted that two fundamental principles of aluminum welding: knowing the role of oxygen and material preparation and how this will affect the result of welding.
Whether you’re a beginner or a seasoned pro, it never hurts to brush up on the basics of welding a certain material, especially one as demanding as aluminum.
First, the most important thing to remember when working with aluminum is that it loves oxygen.
This is useful when corrosion resistance is a factor in your project. The ambient air will bond with the aluminum and form an oxidized layer that has a melting point about twice that of the aluminum itself. Removing this oxidized layer manually or mechanically will allow you to start working with the material.
Second, be sure to clean the material properly and, if possible, only with aluminum tools under controlled conditions. If you don’t have a controlled environment, you will most likely need to clean the aluminum after every 15 minutes of inactivity. It’s how fast it will re-bind with oxygen in the atmosphere and form this layer of oxidation. The filler metal you use will serve you best if you store it airtight or in a dry, warm place to prevent moisture and contaminants from entering.
Do not touch the workpiece and filler metal with gloves or even bare hands. Dirt and grease from your gloves will negate your cleaning efforts, as will the grease from your hands.
Most often, you weld aluminum with AC current using argon as the shielding gas. There are ways to achieve a little extra cleaning by changing the settings, but this will only make a difference if your aluminum is initially clean.
I’m old enough to remember when we worked with 100% helium or a mixture of argon and helium. The helium was great for adding extra heat to the weld, which pierced the oxidized layer for deeper penetration. It was a little more forgiving of the welds. Today, helium is rarely used as it has become too expensive and out of the budget of many stores for consumables.
The workshop has a special area for aluminum processing, separate abrasives, and tungsten grinders, which are used only for aluminum processing. This is all done to try and limit any cross-contamination with other alloys. Aluminum is such a nice material to work with and the results look so good that it’s worth the extra effort, Artem Komarov emphasized.
