February 25, 2020
During coating application and cure, it is critical to accurately measure and monitor environmental conditions. When outside the specified acceptable limits, environmental conditions such as ambient relative humidity, substrate temperature, air temperature, product temperature, as well as dew point can have a significant impact on the coating, during its application, its cure, as well as its performance after cure.
- Cooler temperatures will impact product pre-mixing, mixing, flow and leveling characteristics during application, as well as significantly slow cure times. In the case of epoxy applications, cool substrate temperatures can significantly increase the risk of an amine blush.
- Maintaining a substrate temperature in the 60°F – 85°F during application and cure is very important. Electric heat is the safest heating option during the application of epoxy, as electric heat does not produce carbon dioxide or moisture vapor that will contribute to the formation of an amine blush.
- It is important to note that ALL direct-fired heaters, including natural gas and propane units, produce carbon dioxide and water vapor as the fuel burns to generate heat. In an enclosed area, the carbon dioxide and water vapor produced by direct-fired heat can contribute to the formation of amine blush – especially near the heater. In addition, heaters that use fuels such as kerosene or fuel oil are not recommended because they also produce soot that will deposit on floor surfaces and become a bond breaking surface contaminate.
Figure 1: Example of a direct fired heater. NOT RECOMMENDED as the flame, heat, and exhaust of CO2 & water vapor are released into the application space.
Figure 2: Example of an IN-DIRECT FIRED heater. These are acceptable as unit is stationed outdoors, and ONLY the heat is blown into the application space. The exhaust with CO2 and water vapor is released outside the building.
Figure 3: Example of an 34K BTU electric heater. These are recommended, as there is zero CO2 or Water Vapor produced.
Technical Manager – Midwest