Dirty Material

Definition

A workpiece surface that is not free of substances that will degrade the welding operation.

Description

Dirty material or surface contaminants can have high electrical resistances. This is usually an inconsistent condition on the workpiece and can produce variations in the welding process.

Detection

The condition may be indicated by:

• Cracks and Holes
• Expulsion/Burn Through
• Inconsistent Weld Quality
• Nonround Weld
• Poor Class A Appearance
• Sticking/Stuck Tips
• Stuck Weld
• Undersized Weld
• Contamination of workpieces and equipment

Significance

Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition.