203 Chapter 9 Nonstructural Panel Repair
Copyright Goodheart-Willcox Co., Inc.
Edge Alignment
Figure 9-63 shows an aluminum hood with a
bent edge. The edge is three layers thick and has
work hardening from the bend in the hem. To mini-
mize the chance of cracking, the lip is heated to less
than 400° F with a heat gun. The heating starts at the
perimeter of the bend and works toward the center.
Immediately after the panel is warmed, a wood block is
used as a dolly to support the undamaged areas and
the bend is tapped down with a C-clamp.
Hail Dent
Figure 9-64 shows a heat gun in use to warm a
hail dent in an aluminum hood. The back of the panel
has been checked for adhesive before heating. Move
the heat gun in a circle around the edge of the dent
and work to the center. Monitor the heat to stay below
400° F. When the dent reaches 400° F, remove the
heat. Watch the dent to see if it raises. If the dent
remains, heat again. If two heatings do not raise the
dent, use the following method.
Dent
A larger dent is shown in Figure 9-65. The back
side of the panel was first checked for adhesives, and
none were found. The paint is removed by sanding with
80-grit paper. Studs are welded into the deepest part
of the dent. The bridge spans the damage and hooks
to the studs. Slight upward pressure is applied by the
technician. As the aluminum is heated to 400° F,
more upward pressure is applied with the bridge. A
straightedge is used to check that the low area has
been raised. When the low area is at proper contour,
the perimeter of the dent is lightly tapped with a body
hammer.
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Figure 9-63. Aluminum can crack due to work
hardening. The damaged area on this hood was
heated before the clamp was tightened to minimize the
possibility of cracking.
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Figure 9-65. The bridge spans the damage and hooks
to studs that have been welded into the deepest part
of the dent. Slight upward pressure is applied by the
technician as the damaged area is slowly heated.
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Figure 9-64. Move the heat gun in a circle around the
edge of the dent and work toward the center. Monitor
the heat to stay below 400 degrees F. When the dent
reaches 400 degrees F, remove the heat.
Aluminum hood
Heat gun
Bridge