My father repairs tractors and says he always uses it, but ive never seen anyone else do this. Permatex® Copper Spray-A-Gasket® High-Temp Sealant, 12 OZ – Permatex - https://www.permatex.com/products/gasketing/gasket-sealants/permatex-copper-spray-a-gasket-high-temp-sealant-12-oz/ I think its something like this