Miller Electric 300, 225 manual Excessive Penetration, Burn-Through, Waviness Of Bead, Distortion

	Table 6-5. Excessive Penetration
	Excessive Penetration − weld metal melt-
	ing through base metal and hanging un-
	derneath weld.
Excessive Penetration	Good Penetration
Possible Causes	Corrective Actions
Excessive heat input.	Select lower amperage. Use smaller electrode.
	Increase and/or maintain steady travel speed.
	Table 6-6. Burn-Through
	Burn-Through − weld metal melting com-
	pletely through base metal resulting in
	holes where no metal remains.

Possible Causes	Corrective Actions
Excessive heat input.	Select lower amperage. Use smaller electrode with lower amperage.
	Increase and/or maintain steady travel speed.

Table 6-7. Waviness Of Bead

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

Possible Causes	Corrective Actions
Unsteady hand.	Use two hands. Practice technique.

Table 6-8. Distortion

Distortion − contraction of weld metal dur- ing welding that forces base metal to move.

		Base metal moves
		in the direction of
		the weld bead.
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 amperage for electrode.
	Increase travel speed.
	Weld in small segments and allow cooling between welds.

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