691 Chapter 28 Spray Technique Copyright Goodheart-Willcox Co., Inc. Painting Long Panels When painting a long panel, it can be divided into sections. When using this method, the techni- cian sprays everything within reach. The overlap area should be staggered in successive coats as shown in Figure 28-28. To avoid overlap, the panel can be walked. Figure 28-29 shows a technician walking the panel. In this method, the painter moves the spray gun down the length of the vehicle. This method requires considerable skill and will only work if the painter moves smoothly, without hesitation or skips. Walking demands that the air hose be controlled and kept out of the painter’s way. Panel Refinishing This section explains how each panel of a vehicle should be sprayed. Keep in mind that in most cases, painting starts off the panel and spraying continues past the wet edge. A wet edge is the border between an already painted surface and a non-painted surface. When painting a panel, as in a repair, the paint gun trigger is released when the paint gun reaches the end of the panel. When painting a complete vehicle, seeing the wet edge is important to maintaining the desired amount of overlap (between 50% and 75%). One factor to emphasize in this section is the painter must constantly change body position while spraying. Painting requires stretching, squatting, and reaching. Spraying with a full cup of paint is a demanding, physical job. Always keep the fan properly oriented toward the surface. This will require concen- tration as well as the coordinated movement of the feet, legs, arm, wrist, and hand. Painting a horizontal surface such as a hood requires the application of more paint for good internal flow out. If one painter is spraying a hood, the center of the first stroke should be aimed at one edge. The next stroke, with a 50% overlap, will cover up to the edge. Keep moving toward the center of the hood with each successive stroke. Once the center is reached, the painter should switch to the other side of the vehicle and work from the center to the edge. Figure 28-30 shows this technique. If two painters are available, start in the center with one painter on each side, painting successive strokes away from the center. The roof is sprayed in the same way as a hood. Start at the edge and work toward the other side, switching sides at the center. The height of a car roof will not be a problem for most painters. However, the sail panel will. Paint to the middle of the sail panel so that the paint on the quarter panel can be overlapped. The roof of a pickup truck, SUV, or van will be tall enough to cause a problem for most painters. The roof on a pickup truck can be sprayed in the same way as a car roof if the painter stands on a support. The roof of an SUV or van is much easier to paint if there are two painters, one on each side. They should start in the center and work out from there. The roof will need to be divided into sections. Goodheart-Willcox Publisher Figure 28-29. This painter is walking the length of the truck bed side. This requires considerable skill. Notice the paint gloss. 3rd coat 2nd coat 1st coat Start Stop Start Stop Stop/start Stop/start Start Stop Stop/start Stop/start Stop/start Stop/start Goodheart-Willcox Publisher Figure 28-28. This diagram shows the staggering of overlap areas when painting a long panel in sections. Colored sections are overlap area.