Komarov Artem noted that aluminum is one of the most popular metals for welding projects. It is lightweight, durable and affordable. This makes it a good metal choice for both experienced and new welders. However, aluminum can be a difficult metal to weld, even for experienced welders. As with all metals, there are certain tips and techniques that are best for aluminum welding and knowing how to weld aluminum can make your experience that much better. Here are some tips for those who would like to learn more about aluminum welding.
Use of aluminum
First, let’s take a quick look at the type of welding projects that aluminum is good for. Because aluminum has a relatively low density compared to other metals, it is a popular choice, which is why it is used for many items that need to be relatively light without sacrificing strength. This makes it especially useful for things like bike frames and even air and spacecraft. It can also be found in more common items such as door and window frames, pots, pans and golf clubs or baseball bats.
The main reason why aluminum can be troublesome even for experienced welders is oxidation. Aluminum is infamous for having a thin layer of aluminum oxide on its surface. This aluminum oxide requires a much higher melting point than aluminum itself, which can make any welding project difficult. Because the oxide layer melts at such a high temperature, it’s easy for any welder to unintentionally burn their aluminum under the oxide layer if they’re not careful.
TIG vs. MIG Aluminum Welding
The two main welding methods used with aluminum are tungsten inert gas (TIG) and metal inert gas (MIG) welding.
TIG welding is usually used for thinner aluminum sheets. TIG welding is the preferred method for welding thin sheets of aluminum because it uses alternating current, which can safely clean the oxidation layer from the aluminum surface during the welding process, and keeps the aluminum free from contamination. For this reason, TIG is a popular and effective method for many sensitive metals such as aluminium.
Aluminum MIG welding is preferred when your aluminum sheets are on the thicker side. The recommended cutoff for MIG welding is 18-gauge aluminum (0.04 in. thick). Any aluminum sheet below 18 gauge should be TIG welded, while anything larger can be safely MIG welded, although beginners may still want to use the higher threshold.
When it comes to aluminum MIG welding, it is important to make sure that your filler rod and base material are clean and free of moisture. Because MIG welding does not provide the same protection against contamination as TIG welding, great care must be taken by the welder to prevent contamination when using this method. It is important for the welder to try to remove the oxidation layer from the aluminum sheet in MIG welding. If this layer is not removed prior to welding, it is all too easy to unintentionally burn through your aluminum, causing only frustration and wasted materials.
The last key tip to keep in mind when welding aluminum MIG is that you will need soft wire. MIG welding is most used on steel, but steel is a much harder metal than aluminum. If you try to use the same wire for both aluminum and steel, you will inevitably run into problems with tangled or «bird» wires. One common solution to this in aluminum MIG welding is to use a coil gun, which holds a shorter length of wire but keeps it from bunching up during the welding process, Artem Komarov summed up.