Why Is Aluminum Welding Difficult?

Why Is Aluminum Welding Difficult?

June 23, 2021

All metals aren’t created equal in terms of welding. Some metals are more difficult to work with than others, and aluminum is one of the trickier metals to deal with for a few different reasons. This post will cover why aluminum welding is so challenging:

  • Oxidation: An aluminum oxide layer sits on top of each aluminum piece, and this layer melts at a much higher temperature than the aluminum itself. The welder must use high heat to get through the oxide layer without cutting a hole in the aluminum located directly underneath.
  • Porousness: Aluminum absorbs hydrogen more quickly the more it heats up in its molten state. The hydrogen separates out as the metal returns to its solid state, which may leave bubbles in the material. Any bubbles will result in the aluminum being weak and porous.
  • Impurities: Dirt, air and water can contaminate aluminum during the welding process. These contaminants not only make the metal weaker, but they can also tarnish its appearance. As we’ll see below, cleaning the aluminum thoroughly before welding is essential.
  • Thickness: Welders must work with different thicknesses when they’re working with aluminum. This means they need to avoid burning through thin pieces while ensuring they penetrate thick material to create a strong weld.

How to prepare your aluminum

As mentioned above, welding aluminum requires a bit of prior prep work.  The first step is to remove oil, grease and water from the surface by cleaning the metal with strong soap or a solvent like acetone. Next use a stainless steel wire brush to remove surface oxides.

Once everything is clean, assemble the joint, and cover it if you’re not welding right away to prevent the grime from contaminating the joint. Finally, be sure to keep the pieces dry, and store them at room temperature before welding.

Things to avoid when welding aluminum

Knowing what not to do when it comes to aluminum welding is just as important as knowing how to weld aluminum. Avoid these things at all costs:

  • Taking a one-size-fitsall approach: Using the same welding techniques to fabricate steel as you do for aluminum will lead to disaster. Before welding begins, the welder must be familiar with the best practices for working with aluminum.
  • Not wearing the proper PPE: This mistake can be made while welding any material, but all welders must wear the right personal protective equipment (PPE) when working with aluminum. Failing to wear the right gear can result in severe injuries.
  • Skipping preparation: Skipping the cleaning steps we mentioned above will lead to a disaster. The aluminum piece will look horrible, and it can fall apart easily due to the weakness caused by the contaminants. Additionally, the welder must properly store the aluminum prior to working with it.

We’re the go-to team for your welding needs

With fair pricing, fast turnaround time and experienced pros, our team at Auto Truck Service Inc. is your number-one choice for aluminum welding. Give us a call today to get a quote or to see what we can do for you.

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