168 Section 2 Nonstructural Repairs
labor to install the fender. The total cost of replace-
ment is $250. The repair cost is more than 75% of the
replacement cost, so in this example, the fender would
be replaced rather than repaired.
Easily replaced, low-cost panels, such as fenders
and door skins, are often replaced if they have more
than minor damage. A quarter panel, which is relatively
expensive and time-consuming to replace, will generally
be repaired even when moderately damaged.
Another consideration when determining whether
a panel should be repaired or replaced is the ease of
repair. The ease of repair is directly related to the cost of
repair. Low-crown panels, such as hoods and roofs, may
be replaced rather than repaired if they are damaged.
Repairing a damaged low-crown panel would be diffi-
cult and time-consuming. This is especially true if the
hood is aluminum. A low-crown panel is more difficult to
repair than a high-crown panel.
Figure 8-4 shows a damaged quarter panel. The
metal is torn and there is no access to the back of
the panel. Alignment of the torn edges would not be
possible. Therefore, the panel should be replaced.
Longitudinal force on a body line may cause two or
more buckles to form at a pivot point, such as an internal
brace. These buckles, which are referred to as a double
fold, are close together. The metal in the double fold is
work hardened, both by the panel forming process and
by the damage resulting in buckles. When sheet metal is
severely damaged in this way, the folds are so hard that
straightening would be difficult. Heat could be applied to
the folds while pulling, but the customer would be better
served by replacing the panel.
Similarly, internal brace damage is generally not
repaired. Figure 8-5 shows a damaged hood. The
internal hood braces are bent, and there are double
folds in the metal at the edge of the hood. Because
the brace is attached to the hood skin, the inside of the
brace is not accessible. Repair is not practical, and the
hood should be replaced.
Planning the Repair
Planning involves thinking through each step in
the repair process. Think of a plan as a road map. Can
you reach a destination without a map? Maybe, but
you could end up backtracking. A technician who can
analyze and plan will prevent wasteful backtracking
when making repairs.
To repair panel damage caused by longitudinal
force, the panel’s length must be restored. To repair
damage caused by lateral force, not only must the length
be restored but the surface area may also have to be
changed. In both situations, buckles must be released.
In most types of damage, the panel length should be
restored first, and then the buckles can be released.
Your ability to plan will increase with experience.
Always take the time to devise a plan before starting a
repair. As you develop your plan, you must:
Identify obstructions to be removed (emblems,
moldings, handles, etc.).
Determine if access to the back side of a panel is
necessary and, if so, decide how to access the
back side of the damage.
Determine what tools are needed to make the
repair.
Determine the sequence of basic operations.
Make sure the shop equipment required for the
repair will be available when needed.
Tear
Figure 8-4. This quarter panel was torn open during a
collision. The panel is not repairable.
Internal brace Double fold
Figure 8-5. The internal structure of this hood was
damaged during a collision with another vehicle.
Therefore, the hood should be replaced.