CoatingsPro Magazine

NOV 2018

CoatingsPro offers an in-depth look at coatings based on case studies, successful business operation, new products, industry news, and the safe and profitable use of coatings and equipment.

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74 NOVEMBER 2018 COATINGSPROMAG.COM Industry Insight T hat epigram, by Jean-Baptiste A lphonse Karr, means "Many things remain consistent even as changes happen." roughout history, changes have happened as we need to invent methods and instruments to simplify, mechanize, or lessen the time to perform a task. Take, for instance, the bread slicer, invented by Otto Frederick Rohwedder in the 1920s, or airplanes, compasses, or even concrete. ose were invented by people who saw a need and came up with a means to perform a task. So it has also been within the coatings industry. History Gaged is can be seen with measuring coating thickness — wet and dry — on substrates, such as metals and concrete. Wet-ˆlm coating thicknesses were determined by either coverage/solids by volume or use of a wet-ˆlm thickness comb. Using these combs on concrete is questionable and can be inaccurate due to the concrete's uneven proˆle. But progress happened as the need arose. A savable non-wicking tape is held in a 3" (7.6 cm) diameter container and placed directly in the wet coating, resting on top of the peaks on the steel or concrete. Multiple readings can be measured and retained with this tool. e ˆrst non-destructive dry ˆlm thickness gage to read coating thick- nesses on ferrous metal was invented in 1947. Years progressed, and new instruments were invented. A new design using a magnet for ferrous metals became known as the " banana" gage because of its shape. It is exten- sively used in areas where electronic instruments are not allowed, e.g., šammable atmospheres. Since then, industry needs and inventive minds have designed, reˆned, and brought the method of determining dry ˆlm thick- ness into the electronic age. Type 1 (i.e., magnetic) gages evolved into electro- magnetic gages for ferrous substrates. Eddy current gages are widely used for non-ferrous substrates. e method has changed, but the need to measure coating thickness has stayed the same. As for concrete, although combs had been used for wet ˆlm thicknesses, until approximately 15 years ago there had been no way to measure dry ˆlm thicknesses. Now, the industry has instruments using ultrasonic waves. e original model has since been replaced, and there are now various oŸerings, but the constant was the need to measure coating thicknesses and technology answered the need. Paint inspection gages, originally known as Tooke gages, are following a similar path. Based on perceived coating thickness, currently, one of three blades is chosen, utilizing 45¢ 0', 26¢ 34', and 5¢ 42' angles, and a dry ˆlm coating is cut into. Measurements are made through the use of a 50-power microscope, counting lines on the reticle within. is tool is best used on coatings of contrasting colors and can be used on any surface. Change is coming; companies are developing angled drill bits and a light-emitting diode (LED) microscope that will oŸer a new alternative. Another example: measuring and recording ambient conditions. Evangelista Votecelli is credited with inventing the barometer in 1643. Utilizing mercury instead of water, the tool measures pressure at sea level, and changes to that are read as altitude increased above sea level. at technol- ogy evolved to electronic instruments using sensors and electronics to read air, surface, and dew point tempera- tures and relative humidity. Prior to these, sling psychrometers using thermometers, one wet sock-covered bulb and one dry bulb, along with psychrometric charts were and still are the instruments of choice to measure relative humidity and dew point. Again, one thing stayed the same: the weather and the need to measure it. What's Next e coatings industry evolves as a result of our inquisitive minds and ingenuity. is has led our industry to produce instruments that aid in accuracy and ease of inspection. e same issues and needs remain, but the solutions may diŸer. Expect the industry to continue this change as we progress and learn about new and exciting things. CP Editor's note: See the author's gages through the ages at www.coatingspromag. com/inspection-tools. Photo courtesy of the author By omas R. (Randy) Glover, President and Owner of O.T.B. Technologies LLC "The More Things Change, the More They Stay the Same"

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