685 Chapter 28 Spray Technique Copyright Goodheart-Willcox Co., Inc. the panel, or if the panel is long, the stroke will be the length of the painter’s reach. Figure 28-15 shows the recommended body posi- tion. The painter has one foot positioned near the end of the panel. For a right-handed painter, it should be the right foot. A left-handed painter should use the left foot. Proper positioning and stretching will allow the painter to maintain a consistent distance and speed. If the painter were positioned in the center of the panel, the stroke would be interrupted as the paint gun is moved in front of the painter’s body. Fan Orientation For consistent paint coverage, the fan must strike the surface uniformly. See Figure 28-16. Any fan orientation other than perpendicular to the panel is known as heeling, Figure 28-17. Heeling will cause more paint to be deposited on one end of the fan than on the other. When spraying a horizontal surface, the technician’s wrist must bend as shown in Figure 28-18. This will ensure that the fan strikes the panel uniformly. Vertical surfaces may also require wrist movement to orient the fan properly. Figure 28-19 shows the spraying of a convex panel that curves under. To keep the fan uniform, the technician must tilt the spray gun to follow the panel contour. Because the gun is too tall, it would scrape the floor if it is not tilted. Proper fan orientation takes practice to master. Goodheart-Willcox Publisher Figure 28-15. This left-handed painter positioned his left foot near the end of the panel. Stretching with his legs allows him to maintain the spray gun at a consistent distance. Goodheart-Willcox Publisher Figure 28-14. This table lists spray gun adjustment problems, causes, and solutions. Common Spray Painting Problems and Solutions Problem Cause Solution Excessive orange peel Poor atomization Increase air pressure, decrease material Spray too wet—runs Too close, too slow, too much overlap Increase distance, move faster, less overlap Spray too dry—dry spray Too far, too fast, not enough overlap Decrease distance, move slower, more overlap Air hose or paint suit touches wet paint Lack of coordination Think while you spray Paint gun drips Cup lid leaks Properly install cup lid or replace Incomplete coverage or poor hiding Not enough coats of paint Apply enough paint Tiger stripes Too much air pressure, heeling Decrease air pressure, keep fan perpendicular Mottling Metallic not evenly dispersed Clean air cap properly, adjust spray gun
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