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Thermal Spray Coating for New Construction & Maintenance


Quiz Questions

1.Aluminum and carbon black pigmented silicone coatings may perform at temperatures as high as 650 °C. Special ceramic frit coatings may perform at temperatures of 760 °C.
True
False
2. Thermal spray coatings of aluminum, zinc, and their alloys will provide long-term performance superior to paint coatings at temperatures approaching their respective melting points of 660 °C and 420 °C.
True
False
3.Solvent exposure covers a wide variety of solvent types. Thermal spray metal coatings are essentially unaffected by solvent exposure and are good candidates for service in such environments. Some owners exclude the use of all zinc-containing coatings from use in aviation fuel storage tanks because metal contamination may affect the performance of the fuel.
True
False
4. Thermal cycling may result from normal diurnal temperature variations as well as temperature changes found in operating machinery and process vessels. Thermal cycling induces stresses within the coating. Thermal sprayed metal coatings are more apt to have coefficients of expansion similar to the substrate; therefore, their relative inflexibility does not cause them to fail under normal conditions of thermal cycling.
True
False
5.The pot life of multi-component catalyzed coatings such as epoxies can be greatly reduced by high atmospheric temperatures. High ambient air and surface temperatures can also adversely affect paint application and the subsequent performance of the coating; for example, vinyl paints are prone to dry spray at high temperatures. Most paints should not be applied below a certain minimum temperature because they will not cure or dry. Most epoxy paints should not be applied when ambient and substrate temperatures are below 10 °C; however, there are some specialized epoxy coatings that can be applied at temperatures as low as -7 °C.
True
False
6.Structures in less severe atmospheric environments such as rural areas should be coated with either zinc or zinc-aluminum alloy systems 1-Z and 4-Z-A, respectively. Again, sealing and top coating the thermal spray coating for such mild atmospheric exposures is not necessary but may be done to increase the service life of the coating system or to alter the appearance.
True
False
7. The recommended thermal spray systems for seawater immersion are represented in _________________________.
Table 5-1
Table 5-2
8.The zebra mussel is a freshwater bivalve that colonizes hard substrates. When present in sufficient densities, the zebra mussel can impact the performance of civil works structures and floating plants.
True
False
9.Aluminum thermal spray coatings have been used successfully on metal substrates to prevent corrosion and impart nonskid properties.
True
False
10.Steel reinforced concrete structures such as bridges, parking decks, and piers are prone to chloride-induced corrosion. Chloride ions present in deicing salts and marine atmospheres penetrate the concrete monolith with time.
True
False