186 Section 2 Nonstructural Repairs
Copyright Goodheart-Willcox Co., Inc.
line. As you move the body line, check the progress on
the outside of the panel. If arrowheads are present in
the metal above and below the body line, they can be
released once the body line has been roughed out.
Edge Alignment
Edges of doors or fenders can be pushed in
during an impact. Figure 9-30 shows a fender edge
that has been pushed inward relative to the door. A
slide hammer can be used to pull out the fender edge.
An L-shaped attachment is placed along the edge of
the fender. Tapping with the slide hammer, as shown
in Figure 9-31, will raise the edge of the fender so it
is flush with the door. Note that there is no buckle to
remove in this example.
The door in Figure 9-32 has been pushed in and
has buckled. The edge of the door consists of three
layers of metal: the inner structure, the inner hem
flange, and the outer hem flange. Therefore, the edge
of the door can be quite stiff when buckles form. To
remove the damage, the edge should be raised as the
buckle is worked. An L-shaped attachment is placed on
the damaged edge. As one technician uses the slide
hammer to remove the damage, another technician
taps on the buckle. This task can be accomplished
by one technician. Instead of slide hammering, the
technician can pull on the shaft of the slide hammer
while tapping the buckle. Removing the door is another
method of repair. Locking pliers may be used to align
the edge of the door. Pulling up on the locking pliers
bends the edge of the door. A hammer is used to
tap on the buckle at the rear off the edge. The low
area behind the buckle can be raised with draw pins.
Figure 9-33 shows a dolly to tap up the door edge.
Shrinking
Shrinking reduces the surface area of stretched
metal. Shrinking can also remove false stretch. One
way to reduce the stretched metal’s surface area is to
apply heat. Heat, even the small amount generated by
a draw pin welder or grinder, will cause the stretched
metal grains to thicken. The thickening causes a reduc-
tion in surface area, thereby eliminating the stretch.
The amount of metal shrinkage that occurs
depends on the size of the heated area and the heating
temperature. The heating process must be carefully
controlled. Stretch damage most commonly occurs on
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Figure 9-32. The edge of this door has been pushed
in and has buckled.
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Figure 9-30. This fender was driven back by a front
impact. Opening the driver’s door caused damage to
the fender.
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Figure 9-31. When using a slide hammer to move a
fender edge, line up the hook at the body line.
Buckles