CoatingsPro Magazine Supplements

STEEL 2019

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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COATINGSPRO STEEL SURFACES 2019 21 you not to take readings at areas that will have the lowest film thickness, will you be missing the areas that you should be most concerned about? W hether the coating system is being applied on water tanks, offshore platforms, floating produc- tion storage and offloading (FPSO) units, bridges, refineries, or power plants, edge failure can be a major problem and can cause coatings to fail. e way that specifiers can start to combat this at the start of the project is to specify a stripe coat, which is to simply apply an additional coat of material (typically by brush) to edges/welds/bolts, etc., to build the film thickness. Stripe coating is expensive, but it is one item that can help to maximize coating life. But if stripe coating is expensive, and your inspection personnel can only show up at varied times, how can you be sure that the stripe coating actually happens and to the thickness that's specified? e task is extremely difficult to verify after the fact, and it's nearly impossible to do without damaging the coating. W hat's an inspector to do? Hiding in Plain Sight Coating materials have an interesting property called opacity, or hiding. Defined as the ability of the coating material to obscure the surface color beneath it, opacity is different for each generic coating, each formulation of coating, and even each color of each formulation. By specifying color as a means to assist inspection, the specifying engineer and the facility owner can take a giant leap forward in assisting inspection personnel in verifying compliance with the specification. e contrast of the colors must be significant enough that the minimum dry film thick- ness of the next coat will hide the color of the coating below it. In other words, an off-white primer should not be speci- fied with a white topcoat. Instead, a dark gray primer could be specified with a white topcoat, therefore assuring that a minimum amount of the white topcoat was applied in order to hide the primer below. W hat this allows is the inspection personnel in the field to immediately locate the random potential areas of Coatings have opacity, which can assist the inspector to determine if the minimum film thickness has been achieved. Inspector's Assistant

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