Difference Between Aluminum and Steel Welding

Looking for welding services in the Portland, ME area? Be careful. There are several different types of welding, each with different requirements and considerations, and it’s important to find a contractor with the right experience for your project. With that in mind, we’re taking a closer look at the steel welding offered by American Aerial Services and how it contrasts with aluminum welding.

How Welding Works 

A very quick primer for the uninitiated: welding is the process of joining two metal surfaces by means of a filler metal and heat. The filler material depends on the type of metal being welded, while the heat source — most commonly, either an electrical arc or a torch using acetylene or another fuel source — can vary based on the filler, materials, and other factors. Whether you’re welding steel, aluminum, iron, or another alloy altogether, those fundamentals hold true. After that… well, things start to diverge in interesting ways.

How Steel Welding Differs From Aluminum Welding 

While the underlying principles of welding are broadly similar, steel and aluminum are very different materials, with very different uses.

Melting Points
Different alloys will have different melting points regardless of the base material in the alloy. Regardless of those minor differences, the base metals have vastly different melting points, with aluminum having a much lower melting point than iron, the base metal in steel. The differing melting points and other molecular characteristics mean that each metal has applications for which it’s uniquely suited.

Chemistry
Both aluminum and iron form oxide layers. In the case of aluminum, that oxide layer works as an insulant. In steel, the oxide layer — which most of us know as rust — is a sign of corrosion. The steps taken to address one aren’t directly applicable to the other.

Fillers
Fillers are the materials used to join two sections of metal (and are themselves made of metal). Because of the different melting points and chemical makeups, aluminum and steel require different fillers. Other considerations, such as the use of the welded surfaces, the stresses placed on them, and the types of alloys in use, will dictate the filler metal used. Using the wrong filler can result in stress cracks, damage to metal surfaces, or structural failure, so this is something that ought not to be left to an inexperienced welder.

Technique
Steel welding and aluminum welding also rely on different welding techniques. A weave technique is common in steel welding, but is not advisable in aluminum welding, which calls for a stringer bead instead.

How Steel Welding and Aluminum Welding are Similar 

Up to this point, we’ve explored the differences between steel welding and aluminum. However, there are some important similarities — some of which even emerge from those differences. To begin with, proper storage matters to prevent your base materials and fillers from accumulating dirt, moisture, and contaminants. A follow-on benefit is that proper storage makes your next step — proper surface preparation — quicker and easier as well, since it’s not advisable to weld surfaces that are rusted, filthy, oily, or damaged. But the single most important similarity has less to do with equipment, preparations, or methods. It’s the people. Even if you’re an artist welding sculptures, working with high temperatures and flammable materials is no joke; if you’re working in structural steel erecting, or building steel stairs, the stakes are much higher still. Safety, quality, and long-term function all stem from experience, which is why you should contact American Aerial Services for steel welding services in the Portland, ME area.