aluminium in commercial vehicles - European Aluminium Association

122 EUROPEAN ALUMINIUM ASSOCIATION ALUMINIUM IN COMMERCIAL VEHICLES CHAPTER VIII
9. Surface preparation before welding
For quality welds it is recommended
to machine the edges
(see section 3.7) of sheet to be
welded after water jet, plasma or
laser cutting to remove this
rough surface with a thick oxide
layer and also with micro cracks
in order to avoid weld defects
such as cracks and oxide inclusions.
The same should be done
for plate with thickness over 10
mm that has been sheared.
There is a great risk of cracks in
the short transverse direction,
where a removal of 2 mm via
milling or routing is adequate.
Welding of tipper body (SCHMITZ)
The metal to be welded must be
dry and without contamination
of any grease or other products
that evaporate under the action
of the arc. To achieve this clean
surface, the pieces to be welded
should be brought into the workshop
two days before production.
This will allow condensation
that might occur when the temperature
in the storage area is
lower than in the workshop to
dry off.
Immediately before welding, the
edges to be joined and their surroundings
must be properly
degreased using a solvent such
as acetone or industry alcohol.
Avoid trichlorethylen, which
transforms under the effect of
the arc into the poisonous gas
phosgene. When the solvent on
the surface has evaporated, a
further cleaning with a stainless
steel wire brush (hand-operated
or rotary) is recommended.
Outdoor welding is not advisable.
If it cannot be avoided, the
welding environment must be
screened off.