Changes

==Looking at the Fiber==

==Looking at the Fiber==

What you see depends on how you hold the fiber. The fibers have a square cross-section. If your line of sight is perpendicular to a face of the fiber, you may see only the paint. But holding the fiber up to the light or rotating it can make the underlying color visible. If you rotate the fiber, you can see the color on the shaded underside. Gaining familiarity with the appearance of the fiber as it is rotated may help the worker to recognize a good paint coat.

What you see depends on how you hold the fiber. The fibers have (approximately) a square cross-section. (What look like the sides of the square are in fact curved.) If your line of sight is perpendicular to a face of the fiber, you may see only the paint. But holding the fiber up to the light or rotating it can make the underlying color visible. If you rotate the fiber, you can see the color on the shaded underside. Gaining familiarity with the appearance of the fiber as it is rotated may help the worker to recognize a good paint coat.

==Measuring the Paint Coat==

==Measuring the Paint Coat==

Using a micrometer to measure the paint thickness can damage the paint on a fiber. The sharp edges of the spindle and the anvil can easily scrape off paint as the the fiber is placed between them and as the screw is tightened. Putting masking tape over these sharp edges may reduce damage to the paint. To avoid scraping the paint after recording a measurement, let the fiber fall rather than holding on to it as you are loosening the screw.

Using a micrometer to measure the paint thickness can damage the paint on a fiber. The sharp edges of the spindle and the anvil can easily scrape off paint as the the fiber is placed between them and as the screw is tightened. Putting masking tape over these sharp edges may reduce damage to the paint. To avoid scraping the paint after recording a measurement, let the fiber fall rather than holding on to it as you are loosening the screw.