CoatingsPro Magazine

MAY 2015

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 74 of 92

74 MAY 2015 COATINGSPROMAG.COM Never Again P h o to 1 . A co at i n g s y s te m at a n elementary school started failing; onsite and laboratory analyses were requested. This photo shows the backside of a delaminated coating sample from Area No. 2 (out of five areas tested). By George T. Bayer, Technical Manager, and Tom Thomas, Senior Metallographic and Elastomer Specialist, for Matco Services, Inc. Photos courtesy of Matco Services, Inc. The Case of the Repeated Coating Failures at an Elementary School O ur client, an architectural frm, requested us to conduct an onsite analysis and a laboratory analysis of a coating system at an elementary school. Te purpose of the investiga- tion was to determine the reason(s) for previous coating failures. It was reported that the school was painted on two separate occasions with both of them resulting in coating failures. Te onsite visit was scheduled and took place in July. Our client provided a print of the school 's foor plan and technical data sheets of the coating systems that were previously applied. Te coatings that were used included a vinyl-acrylic latex primer and vinyl- acrylic latex topcoat in school building sections A and K, and a styrene-acrylic latex primer and vinyl-acrylic latex topcoat in building sections B and C. We completed a variety of tests throughout the building to help the owner determine what the causes of the commercial coatings failures were. Tis discussion will include an overview of those tests, results, and recommenda- tions to avoid similar coating failures in the future. Onsite Investigation Te onsite examination consisted of fve separate locations throughout the school. Te locations where identifed as Area No. 1 through Area No. 5. It should be noted that during the onsite visit, the school was in the process of being repainted and that only a limited number of areas were available for examination. Te following testing was performed when applicable: coating assessment, surface profle analysis, gloss measurements per ASTM D523, and adhesion testing per ASTM D 3359. Area No. 1 exhibited coating loss and The stereomicroscopy revealed several areas that appeared to be relatively glossy with uneven and dirty painted surfaces with no signs of abrasive surface preparation.

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