application guide showing the most effective use of the paint systems described in Table 1. These tables offer rec-ommendations for the type of system that will be effective, based on the severity of the environment in which itwill be used, and also indicate the systems that can be used to topcoat various types of existing paints.Interior Structural SteelBefore an appropriate coatings systems for a specific application is determined, it must first be determinedwhether or not a coating system is actually required at all. Currently, many architects specify all interior steel thatis not covered with spray-applied fire protection to be shop primed, even though the steel will not be exposed toview or subjected to corrosive environments. This specification is usually not appropriate and is generally not inthe best interest of the owner.An examination of a number of buildings that had been in use for more than 50 years indicated no corrosion ofany significance whether or not the steel was painted. Some isolated locations of severe corrosion had beenfound in these buildings, but only at localized spots where water had been allowed to seep in and remain in con-tact with the steel for long periods of time. Results of this study led the American Institute of Steel Construction toconclude that structural steel hidden between the exterior cladding of a building and the interior finish need notbe painted.
PAGE 37SYSTEMSAppropriate protection of the steel should be determined by the end-use of the building and the exposure of thesteel structure. The building's service requirements may determine that little or no protection of the steel is nec-essary at all. Steel does not rust except when exposed to atmospheres above approximately 70 percent relativehumidity. Serious corrosion of steel occurs at normal temperatures only in the presence of both oxygen and water.In dry atmospheres (less than 70 percent relative humidity), non-painted steel can be exposed for extremely longperiods of time with no evidence of rusting. If the steel is not painted, a thin transparent film of iron oxide formson the non-painted steel, actually protecting the steel from further corrosion. Therefore, it is difficult to justifypainting all interior steel members as a protective measure for the steel.SYSTEM PRIMER INTERMEDIATE COAT TOPCOAT 1 Inorganic Zinc-Rich Primer Epoxy Aliphatic Polyurethane 2 Waterborne Inorganic Zinc-Rich Primer Acrylic Waterborne Acrylic Waterborne 3 Polyurethane Organic Zinc-Rich Polyurethane Aliphatic Polyurethane 4 Epoxy Organic Zinc-Rich Epoxy Aliphatic Polyurethane 5 Epoxy Epoxy Aliphatic Polyurethane 6 Polyurethane Aluminum Primer*** Polyurethane Aliphatic Polyurethane 7 Epoxy Mastic Epoxy Mastic Aliphatic Polyurethane 8 Oil and Alkyd* Oil and Alkyd* Oil and Alkyd* 9 Acrylic Waterborne** Acrylic Waterborne** Acrylic Waterborne** 10 Polyurethane Micaceous Iron Oxide*** Polyurethane Micaceous Iron Oxide*** Aliphatic Polyurethane Newer Technology Paint Systems11 Polyurethane Organic Zinc-Rich — Polyurethane, High Build 12 Polyurethane Organic Zinc-Rich Polyurethane, water-based
As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.
Temple University Fox School of Business ‘17, Course Hero Intern
I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.
University of Pennsylvania ‘17, Course Hero Intern
The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.
Tulane University ‘16, Course Hero Intern
Stuck? We have tutors online 24/7 who can help you get unstuck.
Ask Expert Tutors
You can ask
You can ask
You can ask
(will expire )