1. Temperature Range
When selecting a high temp coating, the operating temperature range should be the first consideration. At lower temperatures (below 400°F), organic materials can be utilized. Utilizing organic materials alongside inorganic materials in high temperature coatings can provide many benefits. Like a gloss finish, or no heat cure requirement for example. Above 400°F, organic materials break down. For this reason, inorganic materials are heavily relied upon. Inorganic materials like silicone and ceramic allow for extreme temperature resistance. That extreme temperature resistance comes at a cost, however. High temp paints utilizing inorganic materials generally require a heat cure or bake.
2. Application Characteristics
Application characteristics should be a major consideration when selecting your high temp paint. Many “thin-film” high temp coatings (.5-1.5 mils DFT) are available on the market today. These coatings require a relatively thin film in order to stay flexible at high temperatures without cracking. Thin films can be very hard to achieve, especially in a maintenance painting situation. Thicker film options like our 827-HB Series (2-16 mils DFT) are generally preferable. Thick film or high build high temp coatings must exhibit superior flexibility to allow for higher film builds in extreme temperatures. High build capabilities are desired because they allow for a larger barrier from the elements, and a longer service life. Additionally, high build capabilities allow for greater flexibility during the application process.
3. Coating Environment
Another major consideration is the coating environment. We can break coating environment down into three categories: indoor, light outdoor and heavy outdoor service.
Indoor high temperature paint needs include fire places, stoves, etc. A lighter grade coating option will suit most indoor needs. Heat cures are often not a concern in indoor settings because there is no water exposure.
Light outdoor services include grills, smokers, fire pits, etc. These services require a heavier grade coating to stand up to UV rays, and rain water. Selecting a coating with the optimal temperature range becomes very important when dealing with rain water. If the chosen coating requires a heat cure, you must be sure to achieve that temperature before prolonged water exposure.
Heavy outdoor services are considered extremely harsh, and require industrial high temperature coatings. One example can be found in the automotive service category. Many high temp automotive coatings like coatings for exhaust systems, or engine headers require industrial grade performance due to road salt. Extremely harsh service requirements are also found in large chemical processing and refining facilities. In these facilities, industrial high temp coatings are utilized on stacks, kilns, and under insulation. Corrosion under insulation (CUI) can pose a huge threat to the underlying steel pipes. Check back for more on CUI Coatings in a later post.
The final thing to consider when selecting your high temp paint is aesthetics. Color stability in a high temp coating can vary greatly between manufacturers. Selecting a coating that is not only rated to your highest temperature, but color stable to that temperature is important for a few reasons. For starters, it ensures that the painted equipment stays the color that you selected. It can also promote safety. Color coded hot pipes in refineries and chemical processing facilities must maintain their color purity. Paint colors can signify the pipe temperature, or the cargo inside. For this reason, selecting a color stable high temp coating becomes a must.
Thank you for reading our blog. Be sure to check back regularly for more on high temp coatings. Contact us today to get started on your high temperature paint project.