Excessive Sealer

Definition

Too much sealer or adhesive is applied, or it is applied in the wrong location, such that weld quality is affected.

Description

Although some sealers and adhesives are formulated for resistance spot welding, excessive quantities may increase welding interface resistance, impeding current flow.

Weld schedules are typically developed, as required, to weld through sealers and adhesives. A weld made through mislocated sealer may not have the appropriate schedule, potentially affecting weld quality.

Excessive sealer may contaminate the welding equipment, for example tip faces, causing inconsistent weld quality.

Detection

The condition may be indicated by:

• Cracks and Holes
• Excessive Indentation
• Expulsion/Burn Through
• Inconsistent Weld Quality
• Missing Weld
• Nonround Weld
• 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. Special considerations are noted below:

Workplace Issues: Excessive sealer/adhesives may contaminate the workplace environment

Subordinate Causes

• Malfunctions of sealer/adhesive applicator equipment
• Insufficient training of sealor application operators

Notes

Sealer /adhesive dispense rate may be affected by temperature. Ensure that material temperature is within the specified range.