You can "grow" ingredients to make unlimited adhesive in Fallout 4
Adhesive is rather important in Fallout 4 and if you are having a hard time finding it, here's a way to make it yourself.
According to a post on reddit containing information compiled by jredwards, BoyWonder343, Ommageden and tiwuno, there is a recipe in the cooking menu called vegetable starch and apparently, it breaks down into five adhesive.
The recipe calls for mutfruit, corn, and tato which can be grown by the player allowing them to harvest, replant, and eventually gaining a larger crop output as the game goes on.
Purified water is also an ingredient needed in the recipe and there's a way to get it in a easier manner than you think.
The post goes on to tell you where to harvest the tato, corn and mutfruit until you can get a nice garden going, as well as where to get purified water and screws. I am assuming the screw are need to build your own purifier.
Fallout 4 released this week and if you need help, be sure to look over our various guides.