____________________
____________________
____________________
____________________
,
generally
called
arc
welding
or
____________________
welding
,
involves
striking
an
electric
arc
between
the
workpiece
and
an
electrode
-
an
electrical
____________________
.
The
heat
from
the
arc
____________________
the
base
metal
.
The
electrode
consists
of
a
welding
____________________
-
a
stick
of
metal
of
the
same
type
as
the
workpiece
-
which
provides
____________________
.
The
welding
rod
is
therefore
____________________
-
it
is
used
up
.
The
rod
is
also
coated
with
a
material
called
____________________
.
When
heated
,
this
produces
a
shielding
____________________
,
which
protects
the
____________________
metal
from
oxygen
.
Without
this
gas
,
the
hot
metal
would
combine
with
the
oxygen
in
the
air
,
and
this
would
____________________
the
weld
.
