If you are pursuing welding as a new career or are already a seasoned welding technician looking to upgrade your skillset, learning flux core arc welding (FCAW) is an excellent idea. One of the most popular among the many welding processes, flux core welding tends to be highly productive and economical.
First developed a few years after World War II, flux core welding offered an alternative to manual metal arc welding, better known as stick welding. Its primary advantage over stick welding is its continuously fed wire electrode. And there are other benefits to the FCAW method. Read on to discover them.
What is flux welding?
Flux core arc welding is a type of arc welding that utilizes consumable electrodes containing flux. The joining of metal comes about when an electric arc fuses a base metal in the weld joint. The arc is struck between the workpiece and a continuously fed tubular-cored consumable filler wire. The wire and the workpiece melt together to form the weld joint. The flux provides the shielding in the electrode. It melts with the electrode during the welding process to shield the joint, supplying the entire weld area with shielding gas. It protects the weld pool from the atmosphere. The FCAW process can be divided into two types depending on the shielding method: one that uses an external shielding gas and another that relies on the flux core itself to protect the weld area.
Two shielding methods
Dual shield welding: This first method involves an external gas (carbon dioxide) used with flux to provide shielding. The shielding gas is typically either carbon dioxide or a blend of argon (75%) and carbon dioxide (25%). The gas protects the weld pool from oxidation, while the slag formed by the melting flux safeguards the metal.
This shielding method works particularly well when welding thicker metals together. The continuously-fed tubular electrode allows for higher deposition rates when compared to a stick electrode or solid wire.
One of the disadvantages of this process is that strong winds could disrupt the shielding gas, harming the quality of the weld when used outdoors.
Flux core electrode only: The second method relies on the gas and slag formed by the flux-cored electrode to protect the molten material or metal in the weld. The core of the filler wire contains agents that produce shielding gases when the heat from the welding arc burns them.
This method is used extensively used in outdoor projects, even under harsh weather conditions. The primary advantage is that you won’t use an external shielding gas that the wind can disrupt. Another benefit: Flux core electrodes generally make all-position welding possible.
What is flux core welding used for?
Flux core welding has many manufacturing and industrial uses. Because the process offers greater penetration, it is ideal for working with thicker joints, such as would be found in the shipbuilding, mechanical, and construction industries. It is also one of the welding processes recommended for “hardfacing,” a thick coating of wear-resistant material applied to worn surfaces.
FCAW has numerous industrial uses. It can provide excellent weld quality and consistency on the following metals:
- Carbon steel
- Structural steel
- Iron alloys
- Nickel-based alloys
- Stainless steel
- Duplex steels
The high productivity rates of flux core welding make it suitable for projects requiring fast turnarounds. It also provides excellent weld penetration, helping to contribute to a more straightforward joint design. And even though the base metals should be cleaned as thoroughly as possible, FCAW can overcome rust or mill scale contamination much better than most other welding methods.
Although flux core welding is compatible with the needs of professionals and manufacturers, it’s an ideal process to use for welders of all skill levels, including hobbyists, who often need to weld outside or on less-than-pristine material. As mentioned, unlike most welding methods, flux-core welding does not require a clean joint. As long as paint, oil, and moisture have been removed from the weld site, the flux core will burn right through any other imperfections.
Welding hobbyists or newcomers will appreciate that flux-core welding does not require a high skill level. After learning how to set up the equipment correctly, the techniques are relatively simple and easy to grasp.
Does flux core welding work with aluminum?
By most accounts, flux core welding is not the preferred method for aluminum. Most experienced welders seem to agree that there is no suitable aluminum flux core welding wire, and you can’t weld aluminum in your FCAW welder using steel-based flux core wire. You could damage the welding machine and end up with a poor-quality weld.
So what is your best option? Get a MIG welder with a spool gun attachment and use an Argon shielding gas. Or, if you have the skillset, purchase an inexpensive yet high-quality TIG welder for an impressive-looking aluminum weld joint.
Aluminum soldering or brazing are also options if you’re desperate.
Recapping: The advantages and disadvantages of flux core arc welding
Knowing the benefits and limitations of any welding method is vital for both professional welders and hobbyists. There are plenty of advantages to FCAW:
- You have a choice on shielding the weld pool: Using an external gas or a self-shielded flux-cored wire that contains the shielding gas, eliminating the external gas.
- It allows the welding operator to travel in all directions and hold the torch in numerous welding positions.
- Since an external shielding gas is not required, you can weld outdoors with ease.
- The deposit rate for flux-core welding is the highest of any other method. (For example, a MIG welder can deposit up to 8 pounds of wire per hour, while a flux-core welder can deliver up to 25 pounds in that same amount of time).
- Because flux core welding provides greater penetration, it is ideal when working with thicker joints.
- Chances of porosity are minimal.
- Lower start-up costs.
- Less cleaning of base metal is required.
- Self-shielded wire offers significant time savings.
There are also a few disadvantages. Here are some of them:
- It produces slag around the finished joint, requiring clean up to remove it after welding.
- It produces more potentially hazardous smoke and fumes.
- Flux core wire is more expensive than a solid wire electrode.
- It produces more spatter that also requires removal.
- It is not recommended for thin metals.
- Weld beads might not be visually appealing.
- The possibility of slag inclusions.
Are you shopping for a versatile flux core welder?
Look no further! PrimeWeld, a leading manufacturer of high-quality, affordable welders, offers their MIG160. This 160-amp flux core MIG welder provides industrial quality and performance for the professional at a price that will appeal to the workshop welder.
Need a machine for welding aluminum? Check out the MIG180, a powerful 180-amp machine with a spool gun included for aluminum welding.
As with all PrimeWeld equipment, you will receive legendary support and a no-hassle 3-year warranty. Browse our complete lineup of welding equipment today. Then, contact us for more information.