04 welding problems, Welding problems -2, Firepower fp-95 service – Tweco FP-95 Mini MIG User Manual

Page 36

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Manual 0-5122



5.04 Welding Problems




1 Undercut.

A Welding arc voltage too


A Reduce voltage by reducing the voltage selection

switch position or increase the wire feed speed.

B Incorrect torch angle B Adjust angle
C Excessive heat input

C Increase the torch travel speed and/or reduce weld-

ing current by reducing the voltage selection switch

position or reducing the wire feed speed.

2 Lack of penetration.

A Welding current too low A Increase welding current by increasing wire feed

speed and increasing voltage selection switch


B Joint preparation too nar-

row or gap too tight

B Increase joint angle or gap

3 Lack of fusion.

Voltage too low

Increase voltage by increasing voltage selection

switch position.

4 Excessive spatter.

A Voltage too high

A Lower voltage by reducing the voltage selection

switch or increase wirespeed control.

B Voltage too low

B Raise voltage by increasing the voltage selection

switch or reduce wirespeed control.

5 Irregular weld shape.

A Incorrect voltage and

current settings. Convex =

voltage too low. Concave

= voltage too high.

A Adjust voltage and current by adjusting the voltage

selection switch and the wirespeed control.

B Wire is wandering

B Replace contact tip

C Insufficient or excessive

heat input

D Adjust the wirespeed control or the voltage selec-

tion switch

6 Weld cracking

A Weld beads too small A Decrease travel speed
B Weld penetration narrow

and deep

B Reduce current and voltage and increase MIG

torch travel speed or select a lower penetration

shielding gas.

C Excessive weld stresses C Increase weld metal strength or revise design.

D Excessive voltage

D Decrease voltage by reducing the voltage selec-

tion switch.

E Cooling rate too fast

E Slow the cooling rate by preheating part to be

welded or cool slowly.

7 Cold weld puddle

A Faulty rectifier unit

A Have an Accredited THERMAL ARC Service Agent

to test then replace the faulty component.

B Loose welding cable con-


B Check all welding cable connections.

C Low Primary Voltage C Contact supply authority.

Table 5-1: Welding Problems