Would be nice if you told people exactly what materials you are trying to glue together, and for what purpose. Kinda hard to make any intelligent suggestions about an adhesive without this kind of basic information. The fact that you are posting this in a marijuana forum, and are concerned about water resistance would lead me to think you are building a bong. If this is true, you might want to look into an RTV silicone sealant. This stuff sticks to just about anything, dries flexible, resists moisture and moderately high temperatures, and is non-toxic after curing.
