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1.15 Repair methods
1.15.1 Panel beating
NOTE!
Only use aluminium tools for all panel beating work.
The risk of stretching the material is greater with aluminium
than with steel. As a result, aluminium panels should preferably
be pressed rather than beaten. Panel beating procedures
in which the aluminium panel is placed directly between the
counterhold tool and the body hammer, should be kept to a
minimum. Contrary to standard practice with steel panels,
panel beating work on aluminium panels should begin in the
centre of the dent. When panel beating, do not use sharp-
edged or hard tools such as steel hammers.
When performing finishing operations, operate the counterhold
tool loosely. Excessive force applied during finishing actions
may cause the material to stretch. To avoid this, use a
counterhold tool made from hardwood.
1.15.2 Shrinking
Elongation of the material may be rectified by shrinking,
which involves the application of heat. Shrinking is done with
a neutral flame. The shrinking operation involves heating the
area to be shrunk then locally cooling it immediately. As a
result of the rapid temperature change, the aluminium panel
shrinks at the area concerned and resumes its original shape.
The surrounding colder material confines the heated area and
stretches less.
During subsequent cooling, the heated, buckled aluminium
panel shrinks. As a general rule, the repair area must be heated
and cooled quickly when carrying out shrinking procedures.
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2010
1.15.3 Monitoring temperature
Caution!
Outer skin body components may be heated for
straightening and panel beating work provided the
temperature is monitored constantly. Never exceed
180 °C. For precise temperature monitoring, use
temperature indicator pencils or strips or temperature
reading instruments.
Panel beating may be facilitated by applying targeted heat.
When heating aluminium, the material must not be allowed to
tarnish. Consequently, the temperature has to be determined
by means of temperature indicator strips. The different
areas on the temperature indicator strip change colour once
predetermined temperatures are exceeded.
Procedure:
1. Thoroughly clean and confine the area to be heated
2. Temperature indicator strips must be applied at a distance
of approximately 25 mm from the area to be heated
3. Apply the temperature indicator strips spaced at regular
intervals
4. Heat the material while simultaneously monitoring the
temperature.
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