193 Chapter 9 Nonstructural Panel Repair
Copyright Goodheart-Willcox Co., Inc.
One-Sided Repair, Body Line
The steps in performing a one-sided arrowhead
repair that involves a body line are as follows:
1. Raising—Weld a line of draw pins to the
damaged body line. If a gang clamp is available,
hook it up to the draw pins. Partially raise the
body line. If a gang clamp is not available, use
the slide hammer to raise the body line, starting
with the lowest pin and ending with the highest.
After partially raising the body line, weld a draw
pin below the point of the arrowhead. Use a slide
hammer to pull the pin out.
N N N N O O O O T T T T E E E E
A A W-shaped W sh ap ed wire w ir e can ca n be be used u se d in in place p la ce
of draw pins to raise the body line. If
W-shaped wire is used, pull it with a
gure claw handle. See F ig 9-48.
2. Leveling—While pulling out on the pin below the
point of the arrowhead, use a dinging hammer to
lower the sides of the arrowhead. Work from the
outermost parts of the arrowhead’s sides toward
the point.
3. Raising—Return to the draw pins in the body line.
Raise them to the proper height. Set draw pins in
the shaft of the arrowhead. Raise these low areas
by starting at the ends and working toward the
center.
4. Shrinking—Any metal that was pulled too high by a
draw pin can be lowered by shrinking with the draw
pin welder. Heat the area with the welding tip, tap
the heated area twice, and then cool the area with
a wet rag.
Two-Sided Repair, No Body Line
A two-sided arrowhead repair that does not involve
a body line is relatively simple. The high-crown panel
is stiff enough to be metal finished, but it may also be
roughed out and filled. If a change in panel length is
present, begin with step 1 below. If the panel length is
correct, begin with step 2. The steps in performing this
type of repair are as follows:
1. Pushing—Use a four-ton hydraulic power set
to restore the length of the panel. As the panel
lengthens, the lift reaction will raise the low area.
2. Raising—Use a dolly with the same contour as the
underside of the undamaged panel to hit just under
the point of each arrowhead. Start with the deepest
arrowhead and gradually raise each. Continue
tapping with the dolly until each arrowhead is
raised.
3. Leveling—Hold the dolly tightly against the area
under the point. Use a dinging hammer to lower the
high ridges on the side of each arrowhead. Start at
the bottom of the arrowhead and work toward the
point. Alternate sides when hammering toward the
point. The leveling releases the arrowhead.
4. Stretching—If the arrowhead has a sharp point that
was not removed by hammer-off-dolly tapping, use
hammer-on-dolly technique to stretch the upset
metal. Press a dolly with the same contour as the
underside of the undamaged panel against the
inside of the panel, under the point of the arrow-
head. Tap on the point with a stretching hammer.
Goodheart-Willcox Publisher
Figure 9-48. When performing a one-sided arrowhead
repair that involves a body line, raise the body line
first. Here, W-shaped wire has been welded to the
body line and a claw hook is attached to the wire to
pull the damage out.
Goodheart-Willcox Publisher
Figure 9-47. This damage has several arrowheads.
Draw pins are welded at the low areas of each
arrowhead.
Draw pins
Claw handle
W-shaped wire