CoatingsPro Magazine

MAY 2016

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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Page 32 of 84

32 MAY 2016 COATINGSPROMAG.COM Inspector's Corner Inspector's Corner O ne of the frst steps in the inspection of an application is the inspection of the surface over which the coating is to be applied. Te inspection of the surface should include assur- ances that the prepared surfaces are free of any dust, dirt, or abrasive residue from blast clean- ing and that the surface is ready for application of the coating. If the coating work is to be done on an exterior surface, the prepared surfaces should be coated with the frst coat prior to nightfall in order to prevent turning of the surface or moisture conden- sation. Blast cleaned surfaces should not be allowed to stand overnight without frst being coated. If the surfaces to be coated are on the interior, there may be times when they can be allowed to stand overnight prior to coating. Even in this case, however, it is not a good practice, and the inspector should thoroughly re-inspect the surface the following morning prior to the appli- cation of any coating. Inspection of the surface prior to application applies not only to bare steel, but also to previously primed or coated surfaces. It is important that each coat in the system be applied over a perfectly clean, dry surface, and that the previous coats be touched up for any damage prior to the application of the following coat. Care should be taken to make certain that the surface is free from precipitated salts or other impurities between coats. Ensuring Proper Coating Mixing and Thinning Before the application of any coating, the inspector should ensure the proper mixing and thinning of the coating prior to its use. Inspectors should make sure that the material in the containers is the proper one for the job, and that the solids in the bottom of the container are thoroughly mixed into a uniform, lump-free condition. If two-com- ponent materials are being used, each of the components may require proper mixing in order to thoroughly incorporate all of the materials into a uniform liquid. Following the mixing of each component, the mixing of the two components in the proper quantities should be observed. Te mixture of the two materials should, when completed, be uniform in color, texture, and so forth. If thinning is called for in the specifcations, the inspector should check to be sure that the proper thinner and the proper quantity of thinner are being used. Applicators invariably tend to over thin paint, since this makes it easier to apply by either brush or spray. Te inspector must realize that over-thin- ning tends to produce thin flms, thus requiring additional coats to make up for the diference in solid content. Te average specifcation will call for no more than a pint (0.125 gallons) of thinner per gallon (8 pints) of the origi- nal coating. Tis usually will adjust the viscosity to the needs of varied weather The actions of the applicator (i.e., how the applicator handles the gun or the brush, the amount of coating being applied, whether or not he or she is ficking the gun at the end of a pass, and the gun distance from the surface) are all important observations. l p Inspecting Coating Applications

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