Miller Electric 225, 300 manual Excessive Spatter, Incomplete Fusion, Lack Of Penetration

	Table 6-2. Excessive Spatter
	Excessive Spatter − scattering of molten
	metal particles that cool to solid form near
	weld bead.
Possible Causes	Corrective Actions
Amperage too high for electrode.	Decrease amperage or select larger electrode.
Arc length too long or voltage too high	Reduce arc length or voltage.
	Table 6-3. Incomplete Fusion
	Incomplete Fusion − failure of weld metal
	to fuse completely with base metal or a
	preceeding weld bead.
Possible Causes	Corrective Actions
Insufficient heat input.	Increase amperage. Select larger electrode and increase amperage.
Improper welding technique.	Place stringer bead in proper location(s) at joint during welding.
	Adjust work angle or widen groove to access bottom during welding.
	Momentarily hold arc on groove side walls when using weaving technique.
	Keep arc on leading edge of weld puddle.
Workpiece dirty.	Remove all grease, oil, moisture, rust, paint, coatings, slag, and dirt from work surface before
	welding.
	Table 6-4. Lack Of Penetration
	Lack Of Penetration − shallow fusion be-
	tween weld metal and base metal.

Lack of Penetration	Good Penetration
Possible Causes	Corrective Actions
Improper joint preparation.	Material too thick. Joint preparation and design must provide access to bottom of groove.
Improper weld technique.	Keep arc on leading edge of weld puddle.
Insufficient heat input.	Increase amperage. Select larger electrode and increase amperage.
	Reduce travel speed.

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