Why is the FCA welding process not used for open root critical welds?

The FCA (Flux-Cored Arc) welding process is not typically used for open root critical welds due to the potential for slag inclusion and inadequate penetration. Open root joints require precise control of heat and filler material to ensure complete fusion and strength, which FCA may not consistently provide. Additionally, the shielding gas and slag from FCA can hinder visibility and control, increasing the risk of defects in critical applications where structural integrity is paramount. Therefore, processes like GTAW (Gas Tungsten Arc Welding) are preferred for their cleanliness and ability to produce high-quality welds in such scenariOS.