Substrate preparation which includes the removal of contaminates, abrading or etching to create a surface profile via mechanical or chemical methods have a major impact on the adhesion performance of applied coatings. For coatings, a primary performance characteristic is adhesion after exposure to corrosive environments. One of the consequences of corrosion forming under a coating is the loss of adhesion or delamination of the coating.
The electroplating of aluminum has represented a challenge for the coatings industry for decades. The reactivity of aluminum metal leads to a very negative reduction potential. This leads to abundant gas evolution instead of aluminum reduction in water. Current aluminum deposition technology overcomes this limitation by excluding oxygen and water from the process with rigorously dry solvent and airtight plating tanks.
The California Department of Transportation Chemical Testing Laboratory conducted a 5-year corrosion study evaluating the potential effectiveness of using a single component High Ratio Co-Polymerized Calcium Sulfonate (HRCSA) coating to address pack rust and crevice corrosion on the State’s structural steel bridges.
Solution vinyl resin coatings are an effective coating system that have been used on raw water hydraulic steel structures since the 1940’s, including many of the nation’s hydroelectric and lock and dam facilities. The high performance of the vinyl coating is at the cost of releasing high amounts of volatile organic compounds into the air. This study evaluates polysiloxane coating systems as greener alternatives to solution vinyl systems.
Fiber-Reinforced Polymers (FRP) materials are used to rehabilitate and strengthen structures systems and components including but not limited to concrete bridges, columns, marine piers, metallic and concrete pipes, metallic and concrete piles, parking garages, and even storage tanks structures. The growing appeal of this rehabilitation process consists of two primary purposes; to increase shear and load capacity and repair and prevent corrosion degradation.
This paper explores the process of repairing and preparing concrete substrates for application of protective sealers, coatings, or linings. It will present the road map, provided in SSPC SP 13 / NACE 6, “Surface Preparation of Concrete” to attain long term barrier protection performance. It will present the means and methods to achieve a concrete surface suitable for sealer, coating, or lining application.
This presentation will discuss current accelerated testing methods used to approve coatings used on wind tower foundations, towers and other related equipment. The presenter will discuss global coating standards used for system selection, and the presenter will provide potential system upgrades and efforts to allow for extending coating life expectancy to first major maintenance activity. Additional information on related experiences of other industries in environments such as onshore and offshore will be discussed.
Houston’s water system serves more than 4.5 million people regionally and produces more than 146 billion gallons of treated water every year. The city has more than 300 above-grade water line crossings, some of which have been in service for over 75 years. In 2012, Houston Public Works (HPW) implemented a program to inspect every above-grade water line crossing across the city.
For a coatings project to become a Successful Coatings Project, the coatings specification should be clear and concise to be useful to the intended audience. The contractor, the owner and any other parties should be able to find and understand key elements such as the scope, surface preparation (including the appropriate standards) and the specified coating or lining system with the approved alternates.
Using dehumidification for coatings and preservation has been a widely accepted practice for several decades. Over that time, both the coatings and the dehumidification equipment have grown in complexity. While this has made dehumidification more prevalent than ever, it also has made determining what you need as well as actually getting what you need more complicated than ever.
Shot and grit blasting has been around for many years, but are we getting the most from our systems? This paper looks at the various adjustable parameters that can and do affect the productivity (yardage), media usage and effectiveness of a blasting operation. Air flow, pressure and nozzle size all contribute to the efficiency and yardage achievable by a blast pot.