CoatingsPro Magazine

NOV 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 64 of 83

COATINGSPRO NOVEMBER 2015 65 Shown here is a ferrous blasting material imbedded in a coating applied to an aluminum substrate. High Wind Speed Issues In some industr ies, w ind speed may be a safet y concer n, especia l ly when work ing at heights and w ith sw ing stag ing systems; however, it 's of ten neglected w ithin the coating specif i- cation. It seems that common sense wou ld d ictate that dur ing coating application you wou ld not want foreig n debr is to be inc luded w ith the liquid coating f i lm dur ing application nor wou ld you u ltimately want that debr is to be inc luded in the coating f i lm when it 's cured. Even w ithout car r y ing debr is that cou ld be deposited on the painted sur face, excessive w ind speed can sti l l cause problems. T he high w ind speed can ma ke it d if f icu lt to ef fectively transfer the coating whi le in a liquid state to the substrate. Transfer ef f icienc y drops consider- ably, and sig nif icant mater ia l may be wasted — blow n away before it can reach the sur face. Beyond the problems of efficient and effective transmission of the coatings to the surface, w ind speed can also cause solvents to evapo- rate quick ly. T hat may not allow the coating material to remain in a liquid state, so it can ultimately f low out on the substrate in a liquid, forming the required continuous film. A powder y, friable installed coating may be the unintended result. Neither of these resu lts in a coating f i lm that w i l l prov ide the intended f unction in-ser v ice life. It 's obv ious that any fer rous mater ia l embedded in the coating creat- ing r ust stains on a white painted sur face does not prov ide the intended aesthetic qua lit y and is unsight ly. Rea listica l ly, any debr is in the coating f i lm is hard ly acceptable, and, depend ing upon the level of embed- ment and contamination, the f i lm itself cou ld be compromised and w i l l not prov ide the per for mance qua li- ties and physica l proper ties that are ex pected f rom the selected mater ia l. In this case, the material, including abrasive blasting media, metallic and nonmetallic, as well as the paint debris generated during abrasive blasting operations, was embedded in the coating flm at high density. Te embedded ferrous material will, there- fore, continue to corrode and stain the painted surface until it's depleted. So at some point in the future, the staining should cease. Simple Solution So what should the crew have done to avoid this? How about using an enclo- sure around the ship? Unfortunately, though, the case to build enclosures often faces an economic roadblock. Te reality is that the cost to rework and replace installed defective coating systems is far more expensive than the fnancial expendi- ture to enclose and control the work environment during application. Work schedules, timelines, and delivery dates push projects — that's a given. However, it's fundamental to remember that the coating material must be properly installed to provide its intended perfor- mance and function. Enclosures can help to ensure sure that the work efort carries forward to meet those deadlines without compromising the integrity of the installed coating flm. Without enclosures, management of the workspace site becomes impera- tive. Painting and service preparation eforts, such as abrasive blasting, cannot be performed side-by-side and in parallel. High winds can carry debris signifcant distances, so there must be an awareness of how these activi- ties can interfere with the execution of various painting operations. Even Work schedules, timelines, and delivery dates push projects — that's a given. However, it's fundamental to remember that the coating material must be properly installed to provide its intended performance and function. Coatings Failures

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