11 Common Welding Defects and How to Prevent Them

Related reading: The 8 Strongest Types of Welds
1. Porosity
Porosity is marked by the occurrence of gas bubbles within the weld. The bubbles arise when gases enter the weld pool. These bubbles are permanent and cannot be effectively removed when the weld pool has cooled down. Porosity goes beyond being just an aesthetic issue.
Excessive porosity weakens the weld, even to the extent that the welded joint may collapse. Construction codes take porosity seriously, as should local fabrication shops. The hollow bubbles compromise the strength of the weld bead. Fortunately, there are a host of simple preventive measures that can be taken to prevent excessive porosity from occurring.
Welding porosity
How Do You Prevent Excessive Porosity in Welding?
Efforts to prevent excessive porosity begin with keeping everything clean. A leading cause of porosity is contamination, whether it is from the surrounding air at the weld site or the surface of the base metal. The first step to preventing porosity is controlling the flow of air within your shop or project area.
Drafty shop or project area conditions will, unfortunately, provide a steady supply of air to the weld zone. This can be the result of an open door, wind, and weather conditions or air being emitted from machinery. Be mindful of airflow when you are picking a spot for your welding equipment. You certainly want ventilation to carry away welding fumes, but you do not need an unregulated supply of air bubbles.