Evercoat's High Temperature Catalyst eliminates the need to adjust mix ratio ""on the fly"" as the weather changes. The High Temperature formula provides greater work-time flexibility in temperatures above 80F. Reduce the risk of repair defects due to inconsistent mix ratio. Two tubes required for use with Evercoat's Lightweight Filler (EW # 51502A) or one tube with Evercoat's Finishing Putty (EW # 51504A). 10:1 ratio.