65 Excessive Weld Reinforcement

Excessive weld reinforcement is a weld metal built up in excess of the quantity required to fill a groove weld joint. Excessive weld reinforcement can be of two types – excessive face reinforcement or excessive root reinforcement.

Filler metal added to make a groove weld must be as thick as the base metal. A slight amount of reinforcement is usually permitted to avoid the cost associated with grinding the weld metal flush with the base metal. Excessive weld reinforcement, though not as severe as overlap, is undesirable because it thickens and stiffens the section and establishes a stress concentration along the toes of the weld.

Fabrication standards and codes usually limit the allowable amount of excess weld reinforcement. Various welding codes impose a maximum amount of reinforcement for the thickness of the material being welded. Thickness may vary from 1/16” to 1/8”. Excessive weld reinforcement is detected by visual examination (VT) and measurement. If considered a defect, it must be removed, typically by grinding.

Excessive Weld Reinforcement Prevention

Excessive weld reinforcement is prevented by use of the correct welding current, proper welding technique, and appropriate number of weld passes to fill the joint.