The Black Jack 0309‑GA Leak Stopper (Rubber Flexx Clear Flexible Sealant) typically: Dries to the touch in about 1 hour under standard conditions (~77 °F / 25 °C and 50% RH). Fully cures in approximately 3–5 days under the same conditions. Note—cooler temperatures, thicker application layers, or low airflow can extend both drying and cure times. For best results, apply when outdoor conditions are warm (above 40 °F) and there's good ventilation.