MetFab - Air Products Welder's Handbook - Flipbook - Page 30
The number of runs needed to fill the
groove depends on the thickness.
Filling passes
Capping pass
Root run
The deep penetration characteristic of
spray transfer makes it difficult to control
the molten metal in a root run. The root
run can be deposited with dip or pulsed
MIG/MAG or TIG welding.
Alternatively, the underside of the root run
can be supported by a ceramic backing strip
which is removed after welding.
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