Specialty High Heat Ultra Aerosol FAQs Prev Page 1 of 1 Next 1. What is the Difference between High Heat Ultra and High Heat? High Heat Ultra has a rich semi-gloss sheen with excellent color retention. 2. Can I use this inside my fireplace? No, we do not recommend using any place where there are direct flames. We do recommend it for the exterior of a fireplace. 3. What do I do if my can clogs mid project? Twist and pull of spray tip and rinse it in a solvent such as mineral spirits. Prev Page 1 of 1 Next