Steel and aluminum are two common metals utilized in the welding trade. They can be used in a variety of applications, including building construction, automotive production, and appliance manufacturing. Because steel and aluminum each have their own distinct properties, however, they’re welded in different ways. Here’s a closer look.

Pretreatment

All metals should first be pretreated, which involves the removal of rust, dirt, and other impurities that can hinder the welding process. When pretreating steel, sandpaper, grinders, and/or chemical agents are typically used to eliminate any surface imperfections. While pretreating steel is always recommended, it can sometimes be skipped if no obvious corrosion or dirt buildup is present.

By contrast, aluminum pretreatment is essential and can never be skipped; failing to pretreat could result in a weakly welded end product. Aluminum should be cleaned with non-chlorinated solvents and a stainless-steel wire brush prior to work.

Speed

Aluminum is lighter than steel, but it has a thermal conductivity around five times greater. This means that aluminum solidifies much faster than steel. This also means that aluminum can be a more exacting medium to work with. The welder must work quickly and efficiently, and they must get the aluminum weld right the first time—otherwise, distortions will appear as it solidifies.

Melting

Because the color of steel changes as it heats, cools, and solidifies, welders often use the color of the molten steel to gauge where they're at in the weld. This measurement is less effective when working with aluminum.

Aluminum retains a more or less consistently silver color throughout the entire duration of the weld, making it harder for a worker to determine their progress. Again, the key is speed and efficiency with aluminum, and one should always assume there’s a much smaller window of opportunity when welding it to the desired form.

When you need quality welding services, trust the professionals at M & M Welding & Fabrication. For over 25 years, they’ve been providing metal fabricating and ironwork to the Archdale and High Point, NC, region. This local family-owned and -operated business is dedicated to superior craftsmanship and diligent customer care. Call (336) 885-9353 to request an estimate or visit their website to learn more about their services.