Ford F-150 2015 Structural Repair Training Course page 47

Textbook
contact￿tip￿size￿is￿used￿for￿both
steel￿and￿aluminum.
shielding￿gas￿nozzles￿that￿are￿a
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larger￿diameter￿to￿accommodate
the￿increased￿gas￿flow.
Welding￿torch￿position￿and￿travel￿is￿critical￿for￿a
clean￿weld.
There￿are￿differences￿when￿welding
aluminum￿versus￿steel￿include:
greater￿wire￿stick-out￿from￿the
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welding￿torch.￿This￿will￿result￿in
the￿welding￿torch￿being￿further
back￿from￿the￿welded￿surface.
using￿the￿push￿technique.￿This
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technique￿is￿when￿the￿weld￿bead
is￿being￿pushed￿instead￿of￿being
pulled.￿This￿is￿done￿to￿enhance
the￿cleaning￿action￿from￿the
shielding￿gas￿and￿to￿preheat￿the
area￿being￿welded.
starting￿with￿a￿slow￿travel
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speed￿when￿welding.￿This￿is
because￿aluminum￿has￿a￿greater
thermal￿transfer￿efficiency￿than
steel.￿When￿heat￿is￿put￿into￿an
aluminum￿part,￿the￿aluminum
transfers￿the￿heat￿throughout￿the
part,￿unlike￿steel￿which￿holds￿the
2015￿Ford￿F-150￿Structural￿Repair￿Training￿Course￿(FOR06)
Module￿3￿-￿Aluminum￿Joining￿Methods
heat￿in￿one￿area.￿Because￿of￿this
thermal￿transfer￿efficiency￿and￿the
low￿melting￿point￿of￿aluminum,
the￿welding￿travel￿speed￿needs￿to
increase￿as￿the￿welding￿is￿moved
across￿the￿panel.
using￿higher￿amperage￿on
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aluminum￿than￿may￿be￿used￿on
steel.
Only￿use￿the￿recommended￿electrode￿wire￿identified
by￿the￿vehicle￿maker￿when￿doing￿welding￿repairs.
When￿welding￿aluminum,￿there￿are
general￿alloy￿recommendations￿that￿are
published￿by￿organizations￿such￿as￿the
Aluminum￿Association￿and￿AlcoTech.
Ford￿recommends￿using￿ER5554￿on
their￿aluminum￿vehicles,￿with￿1.2￿mm
diameter￿wire.
Some￿vehicle￿makers￿allow￿the￿use
of￿4XXX￿series electrode￿wire￿when
welding￿on￿6XXX￿series￿parts,￿and
5XXX￿series electrode￿wire￿when
welding￿on￿5XXX￿alloy￿parts.￿The
recommended electrode￿wire￿is￿generally
going￿to￿be￿an￿engineering￿decision
by￿the￿vehicle￿maker.￿If￿there￿is￿not￿a
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