With the varying welding methods, wire feed welders are the easiest to handle for new welders.

And if you want to save time and money, choosing flux core wire can be a good start.

But choosing the correct flux core wire is not an easy task, especially if you’re just starting out.

You see, there are factors you should consider first when choosing a flux core wire, such as the base material you will be working on, the flux inside the wire, and the position it is best applied.

All of this can be overwhelming to learn.

Cast your worries aside because in this article we will delve deep into the topic. When you finish reading this blog, you will have all the information you need to decide which flux core wire to choose for your welding project.

 What Are Flux Core Wires

As the name implies, flux core wires are electrode wires that are tubular with a hollow center referred to as flux.

The flux is the chemical compound composed of alloys and deoxidizers, which protect the weld from contaminants. Some wires are made of mild steel and stainless steel and applied to similar materials for better welding capability.

Flux core wires are a productivity driver due to their high deposition rates, performance, and weld quality. These characteristics make these wires a popular choice among welders.

The Two Types of Flux Core Wires

There are two types of flux core: self-shielded gasless and gas-shielded flux core wires.

Self-shielded flux core wire

Self-shielded or gasless flux core wire is the more popular type between the two flux core wire types. The reason for its popularity is simple: portability and mobility.

With a self-shielded flux core wire, you will not need an external cylinder of compressed shielding gas to protect the weld pool from contaminants like water and air. The wire itself provides the shielding gas. In effect, less energy is necessary.  

This feature makes it a versatile wire selection for various base materials of differing thickness and outdoor welding, which beginner welders can take advantage of.  

Gas-shielded flux core wire

Contrarily, gas-shielded flux core wire requires a supplementary compressed gas because it lacks the compounds to produce shielding gas that protects the weld puddle.

The gas from the separate gas tank is either 100% carbon dioxide or argon oxygen mixes, depending on the flux core.

The gas-shielded wire possesses the highest deposition rate among all wire types, which is why it comes in larger spools and diameter sizes compared to the other self-shielded flux core wire.

In effect, it requires a larger and more sophisticated welder that can deliver enough energy output to melt the wire and base metal. 

The welder should also have a tube connected to the gas tank to regulate the releasing speed of the gas shielding. This additional equipment easily translates to a higher voltage requirement, which often racks up to 230+ volts.

This type of flux core wire is not suitable for novice welders because it requires a higher skill level for efficient usage, not to mention the level of understanding necessary to master the complex operation process. 

So it is commonly used in home repair shops with more demanding fabrication and repair projects that weld metals with a thickness of 1/4 inch and above.

How to Pick Flux Core Wires

Ready to choose the wire type you want? Not just yet.

You have to consider the following criteria before deciding which of the two you should use on your project.

Based on welding position

The American Welding Society categorizes the different welding positions into four, which are the following:

• Flat position – This welding position is the fastest way to join thick steel plates by laying the workpiece on a flat surface. 

• Horizontal position – This is also known as out-of-position welding that requires a high level of skill to perform because the weld axis is tilted horizontally.

• Vertical position – This welding position requires the welder to lay the weld and plate vertically during welding, which causes the weld pool to pile up.

• Overhead position – Considered the most challenging and risky welding position, overhead welding requires welders to weld workpieces above eye level.

Each of these welding positions demands different types of flux core wire. But the following will be a good start for you.

• Pick E71T-1 gas-shielded wire for both out-of-position and vertical welding as it provides a faster deposition rate and thicker weld pool.

• E71T-8 self-shielded flux core wire is a good choice when welding in any position outdoors.

• A good choice for flat position welding is E70T-4 self-shielded flux core wire.

A more straightforward way to tell which position the wire is suitable for is to look at the number between 7 and T. When the number is 0, it indicates that the wire is for flat and out-of-position welding. And 1 is suitable for all positions.

Based on the base metal

The second way of choosing a flux core wire is by matching it to the base metal you have.

Let us suppose you are welding mild steel; the superior flux core wire options you can pick are the following:

• Blue Demon E71TGS gasless flux core wire is considered the top choice for its kind.

• INETUB BA71TGS .030-inch gasless flux core welding wire, which you can use for all positions.

• Hobart H222106R19 low carbon steel, flux core wire, which is one of the top-rated wires due to its good match-up for thin gauge mild steel and galvanized steel

• Lincoln Electric CO EDO31448 provides strong welds for sheet metals and mild steel.

The same thing applies if you are working on stainless steel. That is why you should first determine what type of stainless steel your workpiece is. Here are two of the best gas-shielded and self-shielded stainless steel flux core wires according to welders.

• The Blue Demon 308LFC-O gasless flux core wire is your best option when you want to weld stainless steels from the 300 to 308L series.

• The Blue Demon 308LT1/4 gas-shielded stainless flux core wire provides high-performance weldability that can be used for welding types 321 and 347.

When to Use Flux Core Wires

The nature of flux core wires, especially self-shielded, allows you to weld materials when you are outdoors or when welding dirty metals.

Also, you can use flux core wire when you are in a hurry to finish a project or when you are facing an outdoor emergency. 

The shielding gas a flux core wire releases is enough to ignore moderate breeze to protect your weld pool outdoors. Plus, the fast deposition rate allows you to finish fast.

However, despite their outdoor usability, you have to keep both gas-shielded and self-shielded flux core wires away from moisture. Continuous moisture exposure intensely degrades the tensile strength of the wire, which leads to poor weld quality.

Do not use flux core for projects that have 24 to 22 gauge steel as the base metal as this will only end up warping due to high heat. Only use a flux core wire for thick metals that are 18 gauge thick or higher. 

The Bottom Line

Flux core wires apply to almost any base material, such as mild, stainless, and galvanized steel, so they are your best picks when honing your welding skills. Plus, you can also weld thick metals using these wires without so many issues. 

Ultimately, when you want clean, strong, and fast welds, you will never go wrong with either gas-shielded or self-shielded flux core wires.