Understanding Weld Defects and How to Prevent Them

Identify common weld defects, their causes and effective prevention techniques.

Common weld defects include porosity, undercut, lack of fusion, incomplete penetration, slag inclusion, cracks and excessive spatter.

Porosity is usually caused by contamination, moisture or poor gas shielding. Undercut comes from too much current or the wrong electrode angle. Lack of fusion is often the result of low heat input or fast travel speed.

Most defects can be prevented by cleaning the joint properly, using dry consumables, setting correct parameters from the WPS and keeping a consistent travel speed and angle.