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What is Flux Core Welding?


Flux core welding is a process during which an electric arc is used to join a continuously-fed tubular electrode to a base material. Closely related to metal inert gas welding (MIG), the FCAW process uses a hollow tubular electrode filled with flux rather than the solid metal electrode used in MIG.

The flux-cored electrode comprises a metal sheath containing a core of mineral compounds and powdered metals. The weld bead is covered by slag (melted and solidified flux), helping to protect the weld from the atmosphere. The flux is usually removed easily after the weld is completed.

Flux-cored welding has a reputation for being a flexible welding method. Using a flux core welder is suitable for all welding positions when used with the correct filler metal and flux composition. FCAW provides high deposition rates, enhancing the process's productivity and quality welds with an excellent appearance.  

Flux Core Welding Advantages

The flux-cored welding method works well on thicker sections and can even produce a fully-penetrated weld on both sides of a half-inch plate with one pass. Here is a list of the advantages that flux core arc welding has to offer:

  • A deposit rate that's nearly four times greater than stick welding
  • Excellent appearance from a high-quality weld deposit
  • Works well on carbon steel, stainless steel, and low-alloy steels
  • It can be used on metals over a wider thickness range
  • High electrode efficiency and duty cycle
  • Excellent weld penetration 
  • A visible arc that is easy to work with
  • Flux core welding typically requires less pre-cleaning than MIG
  • Self-shielded electrodes eliminate flux handling or gas equipment
  • FCAW is more tolerant of windy conditions 

Flux Core Welding Disadvantages

Here are some disadvantages of flux core welding:

  • It cannot be used with most non-ferrous metals, including aluminum
  • Produces a slag covering that requires a secondary operation to remove
  • More fume is usually generated than with MIG welding
  • Electrodes and equipment are more expensive compared to stick welding