193 Chapter 9 Nonstructural Panel Repair Copyright Goodheart-Willcox Co., Inc. One-Sided Repair, Body Line When performing a one-sided repair that involves a body line, the body line should be raised first. The body line is the strongest part of the damage. Most of the damage adjacent to the body line will be raised with the body line. The steps in performing this type of repair are as follows: 1. Raising—Remove the paint from the low area. Weld a line of draw pins to the body line. W-shaped wire may also be used. Attach a gang clamp to the pins and attach a slide hammer to the gang clamp. See Figure 9-43. Pull, slide hammer, or use a combination of pulling and slide hammering to raise the body line to within 1/8″ (3.2 mm) of its proper height. Try pulling first because the force is more controllable. If a gang clamp is not available, weld a draw pin to the lowest part of the body line and pull up the body line. Continue this process, working the next lowest portion, until the entire damaged area has been raised to within 1/8″ (3.2 mm) of its proper height. Be careful not to raise the body line too high. 2. Leveling—Use a dinging hammer to tap down the high spots around the low area. Pulling on the draw pins holds the panel in place, preventing it from moving down while tapping with the hammer. This is similar to the way a dolly supports a panel while hammering off-dolly. 3. Stretching—The heat of the draw pin welder may compound the problem of upset on the damaged body line. If false stretch is present, lightly tap on the straightened body line. This may eliminate the problem. 4. Shrinking—To prevent chasing the dent, tighten the metal around the area to be filled with a shrink fence. The shrink fence may also correct a false stretch. If false stretch is still present after the shrink fence is made, try raising the body line. If the body line cannot be raised further, use the draw pin welder to shrink the false stretch. Two-Sided Repair, No Body Line In a two-sided repair that does not involve a body line, both the inside and outside of the damage are worked. The main concern is to prevent additional stretch to the panel. This type of repair is performed as follows: 1. Raising — Use a dolly that is large enough to span the dent and that has the same contour as the outside of the panel. See Figure 9-44. If the dolly spans the dent, it will prevent raising the metal too high. Tap the dent with a pick hammer. Do not hit the dolly hard enough to make it ring. Light blows are best. Gradually raise the dent. If a dolly is not available, raise the dent by blind picking. Be very careful using this method. The picking will reduce the surface area of the dent. 2. Picking and filing—File across the dent. Bright shiny areas indicate high spots. There may be a high spot surrounding the dent. Lower the high spots by picking, while supporting the panel from underneath with a dolly. Do not hit the dolly when picking. Goodheart-Willcox Publisher Figure 9-43. The body line is the strongest part of the damage. The shaft of a slide hammer is shown pulling the body line. Gang clamp Slide hammer Goodheart-Willcox Publisher Figure 9-44. Raising a dent with a pick hammer also shrinks the panel. Dent Dolly