Wrong Tips

Definition

One or both of the electrode tips installed is not of the design or material intended for the application.
Same as: wrong caps, improper electrodes, etc.

Description

Electrode tips are available in various shapes, sizes, and materials to suit the design of the welding equipment, the geometry of the parts being welded, or the material being welded. Substitution of an inappropriate tip may adversely affect the available current carrying area, the parallelism or alignment of the tip faces, the amount of current required, or the shape of the resulting weld.

Detection

Detectable evidence may include:

• Excessive Indentation
• Cracks and Holes
• Expulsion/Burn Through
• Mislocated/Edge Weld
• Sheet Metal Distortion
• Poor Class A Appearance
• Sticking/Stuck Tips
• Stuck Weld
• Undersized Weld
• Visible mismatch of tip faces when the welder is closed (face shape, size, nonparallelism, misalignment)

Significance

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

Quality:

• No-welds or undersized welds could result.
• Excessive indentation and expulsion may weaken the weld and be visually unacceptable.
• Edge welding may occur.

Workplace Issues: Edge welding may result in heavy expulsion leaving sharp edges.

Cost:

• Reduction in tip life may increase welding costs.
• Undersized welds may increase levels of rework

Downtime:

• Wrong tips may have to be changed immediately, necessitating downtime.
• Excessive sticking may occur.

Throughput: Any downtime will reduce throughput.