HPC®-HT Primer is a single-component resin, water-based coating using specific ceramic fiber loads for application directly over surfaces 200°C (392°F) and up to 600°C (1112°F). It was designed to provide the initial adhesion over extremely hot surfaces before the heavier-loaded HT is applied. HPC®-HT Primer offers a ‘green’, nonflammable, non-toxic formula for high-heat surface priming. HPC®-HT Primer is easily applied, and can be applied direct to metal, concrete and other high- temperature surfaces. It will seal and block CUI over hot surfaces.

https://spicoatings.com/hpc-ht-primer/