196 Section 2 Nonstructural Repairs Copyright Goodheart-Willcox Co., Inc. 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 arrow- head. 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. Never file on the body line. Filing on a sharp corner may cut through 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. CAUTION 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 Goodheart-Willcox Publisher Figure 9-50. In a tight fold, the folds touch. Stretching is necessary when repairing these types of folds. Folds touch
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