Why is it important not to remove the filler rod out of the shielding zone?

Maintaining the filler rod within the shielding zone is crucial primarily because it prevents contamination of the weld. When welding, the shielding gas creates a protective environment around the weld area, which is essential in preventing atmospheric contaminants, such as oxygen and nitrogen, from coming into contact with the molten metal. Removing the filler rod from this zone can leave it exposed to these contaminants, which can lead to defects like porosity or a weakened weld due to the unwanted absorption of atmospheric gases.

Contamination can compromise the integrity of the weld, leading to various issues, including reduced strength and compromised physical properties of the welded joint. Therefore, keeping the filler rod where the shielding gas is present ensures that the rod and the weld pool are protected from these harmful environmental factors during the welding process.