Occasionally, too little catalyst or older catalyst will cause the silicone to cure more slowly than normal. This type of silicone likes warm moist environments to cure in. To help the silicone cure, take a wet washcloth or hand towel and place it in the microwave. Warm the towel until it is steaming. Open the microwave door and place your mold box in there (do not turn the microwave on!). Let the mold sit in there and steam until the cloth cools. The heat and steam will assist with the silicone curing. You may have to pull the mold out and repeat the process to keep the cloth wet, hot, and steaming. Doing this a few times may help get the silicone further along in its cure cycle.