*PLUMBERSSTOCK EXPERT* responded:
Hello! We appreciate your interest in our Hardcast 304156 1 gallon duct seal 321 water-based duct sealant. According to Hardcast, this product does dry into a hardened surface. The cure time is between 24-48 hours. If you want to purchase this product, feel free to click Add to Cart, enter your zip code and you're good to go. Happy shopping!