194 Section 2 Nonstructural Repairs
Copyright Goodheart-Willcox Co., Inc.
Start with light taps. If the metal does not stretch,
tap harder. Use the dolly to raise the low areas that
remain once the arrowheads have been released.
Tap out on the underside of the panel with the
dolly. If an upset area—a V-shaped groove in the
shaft—remains, it can be removed by hammer-on-
dolly stretching. Start hammering on the dolly at
one end of the V-groove and work toward the other
end. See Figure 9-49.
5. Picking and filing—File across the damage. Any
shiny spots indicate high areas. Tap the high areas
down with a pick hammer. Areas not touched by
the file are low areas; raise them by blind picking.
Continue picking and filing until the repair area is
smooth.
Two-Sided Repair, Body Line
Before beginning a two-sided arrowhead repair
that involves a body line, determine which damage is
stronger, the arrowhead or the body line. The strongest
area is the deepest or has the most buckles. Start on
the strongest area first. Most of the time it will be the
body line.
1. Raising—Use a body chisel against the back side
of the panel to partially raise the body line. It may
take considerable force to get the body line to
move. After raising the body line, use a dolly with
the same contour as the underside of the undam-
aged panel to hit the underside of the panel below
the point of the arrowhead. Continue to hit the
panel until the buckle begins to unfold.
2. Leveling—While pushing out with the dolly under
the point of the arrowhead, use a dinging hammer
on the sides of the arrowhead. This hammer-off-
dolly operation will lower the ridges and raise the
point. Start hammering away from the point, alter-
nating sides while working toward the point.
3. Raising—Use the body chisel to complete the
raising of the body line.
4. Stretching—Use a dolly to bring up the shaft
portion of the arrowhead. Then use a stretching
hammer to correct the upset, starting at the point
of the arrowhead. Hold the dolly tightly against the
underside of the panel as the stretching hammer
is used on the dolly. The stretching starts at both
ends of the shaft and progresses toward the
middle.
5. Filing—File across the damaged area. Low spots
are areas that the file does not touch. Raise them
by blind picking. High spots can be felt as resis-
tance when filing or seen as shiny spots after filing.
Tap down high spots with a pick hammer.
C C C C C C C A A A A A A A U U U U U U U T T T T T T T I I I I I I I O O O O O O O N N N N N N N
Ne Ne Ne er ve ve r r file fi fi le le on o o n n the th th e e bod bo bo dy dy line l l in in e. e. Filing F F il il in in g g on on on a a a
sharp p corner may y cut through g it.
Folds
Folds are caused by longitudinal force and are
corrected by lengthening the panel. This type of
damage can be remarkably easy to repair if you
understand how it was created. To make this repair,
use corrective force that is the opposite the force that
created the damage.
Fold Repair, No Brace
In this type of repair, panel length is restored as the
folds (buckles) are removed. If a body line is present, it
is repaired along with the folds. The following example
explains how to repair a damaged quarter panel, as it
is the panel most likely to be repaired in this way.
1. Pushing—Set up a four-ton hydraulic power set
inside the trunk. The base should be set against
the wheelhouse and the pushing end should
be located at the direct damage. As the ram is
extended, the panel will lengthen and the damage
will walk out.
2. Leveling—As the power set lengthens the panel,
you must work the folds. Relieve the folds furthest
from the point of impact first. The low areas are
raised and the high areas are lowered by the
hammer-off-dolly process. Gradually increase
panel length as the folds are removed.
3. Stretching—Tight folds (where the folds touch),
such as those shown in Figure 9-50, are upset.
Hammer-on-dolly work will increase the surface
area.
4. Filing—File across the repair area to identify high
areas and low areas. Avoid any body lines. Pick
and file to restore panel contour.
Goodheart-Willcox Publisher
Figure 9-49. This diagram shows how to stretch a
V-groove.
Dolly location for
hammer-on-dolly
Dolly location for
hammer-off-dolly
Hammer site for
hammer-off-dolly