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Tandem MIG/MAG welding
was reborn
The development of welding technology has made giant leaps
in recent years with regard to power sources. Systems and
processes that were considered the cutting edge at the turn of
the millennium are now outdated.
In the 1990s and early 21st
century, tandem welding was
among the processes that were
supposed to become a credible
competitor for other high-power
welding methods. However, this
never happened because the process was
cumbersome to use. New technology
has now improved the level of usability
substantially, and it has become faster
and easier for the operator to adjust the
welding parameters.
The delivery of a KempArc
Pulse TCS system typically
includes the following
components:
• Two KempArc Pulse TCS power
sources
• Two DT400 wire feeders
• The required connecting cables
• An efficient KempCool 40 water
cooling unit
• A tandem welding torch
• Two WiseFusion functions
• Welding programs acquired by the
customer (MatchCurve)
What is actually meant by tandem
welding It belongs to multi-wire
welding methods. A MIG/MAG tandem
uses two filler wires during welding. This
must not be confused with twin-wire
MIG/MAG welding that also uses two
filler wires. The main characteristics of
these processes are the following:
Twin wire welding
• Two filler wires are fed into the same
weld pool through a shared two-hole
contact tip either from the same
wire feeder or two separate ones.
• The wires are at the same
electric potential.
• There is either a single power
source or two power sources
connected in parallel.
• The wire feed rate is the
only parameter that can be
varied between the wires.
• The same welding power has to
be used for both filler wires.
Tandem welding
• Two filler wires are fed into
the same welding pool through
two contact tips electrically
isolated from each other.
• There is a separate wire feeder and
power source for each filler wire.
• The filler wires are at different
electric potentials.
• The welding parameters can be
adjusted separately for each filler
wire (master and slave wires).
There are many process variations for
tandem MIG/MAG welding. The issue
can be considered from the viewpoint of
MIG/MAG arc types or filler materials
used. Variations related to the arc type
may include pulse-pulse, spray-pulse,
spray-spray and in some cases pulsespray
arc welding. The two filler wires
may have different properties: they can
be of different thickness and alloy, and
one can be solid while the other is fluxcore
wire. The basic idea is that the
leading filler wire is used to make the
weld penetration, and the trailing one is
used to shape the weld surface.
Tandem MIG/MAG welding is
aimed to provide the following
advantages over single-wire
welding, for example:
• Welding of small throat thickness
(thin sheets) can achieve a
higher welding speed compared
to single-wire technology.
• Welding of large throat thickness
(heavy structures) can achieve a
greater melting efficiency compared
to single-wire technology.
• The overall quality of
the weld is better.
• A longer weld pool makes
gases escape more efficiently,
which decreases porosity.
• Because the welding energy input
is lower in spite of the greater
melting efficiency, welding causes
less deformations and reduces
the need for straightening.
• No special shielding gas is
needed for the process.
16 Kemppi ProNews 2011