A leaky humidor is when there is a gap between lids or the points where sides of the box meet so that the humidity escapes from the leaks. The result is dry cigars. There are certain ways in which this leak can be prevented and how to overcome this problem. One of them is by using silicone. Buy silicone that is non-toxic and environmentally friendly. Remove all the cigars and sources of humidification. Place the silicone inside the box and let it sit for 3 days. After 3 days, remove the silicone and place the humidification source again to attain 70% humidity.