Obsolete sealant that won't cure - Original expiration date removed and new fake expiration date sticker added. UPDATE: After further careful examination of the partially legible original expiration dates on two tubes of sealant, I finally concluded that the date placed above the sticker was probably correct. Dow Corning's specs said it should come off after 3 hours, but after 12 hours it was still very sticky and although the humidity was very high to speed up the process, the temperature was only 64C (DC says 3 hours is time). humidity 50% and 77). So I put a propane heater in my garage and heated it to 95 degrees overnight and then in the morning it was completely dry and seems to be hardening normally. DC says the cure time is 7 to 14 days (yes, days, not hours), so 795 is pretty different from the 24-hour cure silicone you can get at Homedepot.