Dual shield welding – Fundamentals, Tips, Tricks, Pros & Cons

Is Dual shield welding the same as Flux-cored arc welding?

Fundamentally, the dual shield welding process is based on the flux-cored arc welding process, but as the name states, dual shield welding uses both shielding gas and FCAW electrodes. Therefore, the molten metal is protected from the environment by both a slag system and an external shielding gas.

ESAB was one of the manufacturers that pioneered the development of gas-shielded flux-cored arc welding in the 1950s. As a result, FCAW overcomes many of the restrictions associated with manual metal arc welding (stick welding) since it uses a continuously fed wire electrode.

As a welder, you might have noticed some people refer to Flux core welding as dual shield welding. Dual shield welding combines electrodes from flux core arc welding and shielding gas for MIG welding. Let’s see how it works.

Basic Fundamentals of Dual shield welding

The dual shied welding process uses heat generated by an electric arc to fuse base metal in the weld joint area. As a result, an electric arc is formed between the workpiece and the continuously fed flux-cored wire. Due to heat caused by an electric arc, the wire and the base metal melt together to form a weld pool.

The wire adds the desired level of alloy elements to the puddle, which affects the structural properties of the weld metal. In addition, the filler metal produces a slag to coat the weld, which is courtesy of self-shielded wires.

As the molten metal solidifies, it can react with gases in the atmosphere, eventually contaminating the weld. That’s where shielding gas provided externally plays a crucial role.

Most commonly, welders use 100% carbon dioxide (CO2) in the dual shielding process. That way, you will get excellent penetration and the ability to weld thicker metal.

As an alternative, you can use a mixture of 75 – 85% argon (Ar) and 15 – 25% Carbon Dioxide (CO2). Even though this is the most frequently used blend, it is more expensive. However, you get decent penetration with high-quality welds and higher deposition rates.

So you can deduce that the dual shield welding process utilizes the advantages of both MIG welding and Flux-cored arc welding, but welders still wonder: why do you use it?

Dual shield welding Applications

When talking about welding applications, Dual Shield Flux Core Arc Welding is similar to MIG/MAG welding and Stick Welding. The process is most often manual, but welders can automate it depending on the nature of the welding job.

Overall, this is a flexible welding process suitable for all position welding, given the correct filler material and flux composition. In addition, due to high deposition rates, it is highly productive and provides high-quality welds with a good appearance.

This welding method’s high welding speed and portability make it widely used in construction. Flux core welding can be readily performed outdoors, even in windy conditions, but dual shield variation can be effective within wind shelters.

When mechanized, dual shield welding can be used in most automobile and machine fabrication industries.

Since dual shield wire can be used for a range of alloys, plain carbon, stainless and duplex steels, flux-cored arc welding is also frequently used for surfacing and hardfacing.

Weldable Materials

Dual shield welding works well with most carbon steels, cast iron, stainless steel, and hard-facing/surfacing alloys. However, there are limitations in welding non-ferrous exotic metals, such as aluminum. So if you want to learn how to weld non-ferrous metals or what welding methods to use, feel free to check out our detailed article.

Transfer Types and Polarity – Globular or Spray Transfer

Globular and Spray Transfer are the most frequently used transfer methods. However, spraying arc is more prevalent among welders due to high deposition rates, good penetration, and aesthetic look.

You can opt for the globular method when choosing economical shielding gases such as pure CO2 since it offers low costs with higher penetration.

However, even though the globular transfer is suitable for thicker metals, you should expect a bit more spatter.

Regardless of the transfer method, most dual shield fluxed core electrode manufacturers recommend DC+ polarity.

Dual shield welding Pros & cons

Even though dual shield welding combines good sides of both flux core arc welding and MIG welding, it has its advantages and drawbacks. Since no welding method is perfect, let’s discuss the pros and cons of this variation.

Shielded Flux Core Welding Tips

• Make sure you clean slag formation after every substantial pass
• Store your wire and choose adequate filler material
• During overhead welds, make sure you increase welding travel speed
• Knurled drive rolls ensure smooth wire feed with soft flux-cored wire
• When welding thinner metals, it is better to weld down vertically. For metals thicker than 1/4″ weld up
• When welding significantly thicker materials welders should opt for pure CO2 shielding gas
• When weld appearance is more crucial, you should opt for 75% argon and 25% carbon dioxide
• Make sure there is adequate ventilation to avoid health hazards when working inside
• When working with flat welds weld at 90 degrees and 10 degrees back, for T Joints angle should be 45 degrees while Lap joints require welds at 60-70 degrees
• Limit wire stick out