If you make art projects with paper or cardboard, you have surely worked with white glue. White glue is great for bonding paper and cardboard as it penetrates the fibres of the paper. Unfortunately, sometimes, children don’t put the caps back on the bottles of glue and then the glue dries in the cap and that makes the bottles of glue unusable. But there is a simple solution to remedy this situation.
Unscrew the cap of the bottle of glue and place it in a metal container with hot water for an hour or two. If necessary, replace the water. The white glue will gradually soften and dissolve in the water. If necessary, you can use a toothpick to remove the residues that are a little tougher. To prevent the glue from drying in the bottle while you are cleaning the cap, cover the opening of the bottle with a piece of plastic wrap until the cap is cleaned. When the cap is clean, remove the plastic wrap and replace the cap on the bottle of white glue.
Schools and daycares use a lot of white glue. The advantage of cleaning the caps of the white glue bottles, is that it saves a bit on costs. You can recycle the same bottles and refill them from a large bottle or jug of white glue. Moreover, that gives a positive message to children about the importance of recycling.