Hobart Welding Products OM-227 978B Troubleshooting − Waviness Of Bead, Weld bead, Application

9-14. Troubleshooting − Waviness Of Bead

Waviness Of Bead − weld metal that is not parallel and does not cover joint formed by base metal.

S-0641

Possible Causes

Corrective Actions

Welding wire extends too far out of nozzle.

Be sure welding wire extends not more than 1/2 in (13 mm) beyond nozzle.

Unsteady hand.

Support hand on solid surface or use two hands.

9-15. Troubleshooting − Distortion

Distortion − contraction of weld metal during welding that forces base metal to move.

Base metal moves in the direction of

the weld bead.

S-0642

Possible Causes

Corrective Actions

Excessive heat input.

Use restraint (clamp) to hold base metal in position.

Make tack welds along joint before starting welding operation.

Select lower voltage range and/or reduce wire feed speed.

Increase travel speed.

Weld in small segments and allow cooling between welds.

9-16. Common MIG Shielding Gases

This is a general chart for common gases and where they are used. Many different combinations (mixtures) of shielding gases have been developed over the years. The most commonly used shielding gases are listed in the following table.

		Application
Gas	Spray Arc Steel	Short Circuiting Steel	Short Circuiting	Aluminum
			Stainless Steel
Argon				X
Argon + 25% CO2		X
80% or greater Argon +	X	X1
balance CO2 or Oxygen
100% CO2		X
Tri-Mix2			X

1Limited short circuiting use

290% HE + 7-1/2% AR + 2-1/2% CO2

OM-227 978 Page 37