Arc blow

Porosity

Over lap

Crack

Manual metal arc welding

Tungsten invert gas welding

Malattic invert gas welding

Oxy - acetylene gas welding

Formed over lap

Spatterns are more

Electrode fused speedly

Base metal edges not melt properly

To reduce the welding run

To control defects in weld joint

To speed up the welding joint

Align and to maintain the position of joint

Less weight

Oxide formation

High thermal conductivity

Better strength weight ratio