Here are five easy recipes to make glue. All of these homemade glue recipes are non-toxic and made using simple kitchen ingredients. Make glue yourself if you’re out of a store-bought product or just prefer natural ingredients.
Why Glue Is Sticky
Making homemade glue is economical, plus it’s a good science project that explores the properties of adhesives. Syrup, cooked flour, and sugar are sticky because of the nature of their molecules. Specifically, hydrogen atoms on the surface participate in a type of chemical bond called hydrogen bonding. Hydrogen atoms are attracted to their own molecules and also to any surface with a slight negative charge. When liquid, a glue has many exposed hydrogen atoms that are happy to stick to whatever they touch. As glue dries, the molecules aren’t as free to move, so the glue stops being sticky.
Non-Toxic Milk Glue Recipe
The best all-purpose homemade glue uses milk as a base. This is essentially how commercial non-toxic school glue is made. Customize the glue recipe to make a thick paste or a flowing glue.
- 1/4 cup hot water
- 2 tablespoons powdered dry milk or 1/4 cup of warm milk
- 1 tablespoon vinegar
- 1/8 to 1/2 teaspoon baking soda
- More water, to reach desired consistency
- Dissolve the powdered milk in the hot water. If you’re using regular warm milk, start with just that.
- Stir in the vinegar. You’ll see a chemical reaction occur, separating the milk into curds and whey. Essentially, this reaction forms a plastic from the milk. Continue stirring until the milk has completely separated.
- Filter the mixture through a coffee filter or paper towel. Discard the liquid (whey) and keep the solid curd.
- Mix the curd, a small amount of baking soda (about 1/8 teaspoon), and 1 teaspoon hot water. The reaction between the baking soda and the vinegar causes some foaming and bubbling.
- Adjust the consistency of the glue to suit your needs. If the glue is lumpy, add a bit more baking soda. If it is too thick, stir in more water.
- Store the glue in a covered container. It will last 1 to 2 days at room temperature and 1 to 2 weeks if you refrigerate it.
Make Corn Syrup and Corn Starch Glue
Here’s how to make a simple and safe glue based on cornstarch and corn syrup. You could substitute potato starch and another type of syrup if you prefer. Starch and sugar from syrup are sticky on their own, but both get stickier when heated.
- 3/4 cup water
- 2 tablespoons corn syrup
- 1 teaspoon vinegar
- 2 tablespoons corn starch
- 3/4 cup cold water
- In a saucepan, stir together the water, corn syrup, and vinegar.
- Bring the mixture to a full boil.
- In a separate container, stir the corn starch and cold water to make a smooth mixture.
- Slowly stir the corn starch mixture into the boiling corn syrup solution. Return the glue mixture to a boil and continue cooking for 1 minute.
- Remove the glue from heat and allow it to cool. Store it in a sealed container.
Easy No-Cook Paste Recipe
Simply mix flour and water to make a basic glue. The reason this works is because water hydrates molecules in flour, making them sticky.
- 1/2 cup flour
- Pinch of salt
- Stir water into flour until you get the desired gooey consistency. If the paste is too thick, add a small amount of water. If it’s too thin, add a bit more flour.
- Mix in a small amount of salt. This helps prevent mold.
- Store the paste in a sealed container to keep it from drying out. You can refrigerate it, if desired.
How to Make Flour and Water Glue
Just mixing flour and water makes a simple glue, but it’s much stickier if you cook it before use. The same principle makes gravy in cooking.
- 1/2 cup flour
- 1/2 to 1 cup cold water
- In a saucepan, whisk together flour and cold water. Use equal portions of flour and water for a thick paste and add more water to make glue.
- While stirring, heat the mixture until it boils and thickens. If it is too thick, you can add a bit more water. Keep in mind that this recipe will thicken as it cools.
- Remove the glue from heat. If you like, you can stir in food coloring or glitter. Store the glue in a sealed container.
Make Natural Paper Mache Paste
Paper mache (papier mache) paste is a natural glue made from kitchen ingredients. Paint this thin, flour-based glue onto paper strips or else soak paper in the paste before applying it to a surface. The thin consistency helps the glue penetrate many layers and hold them together. Paper mache paste dries with a smooth, hard finish. It’s used to make piñatas, models, and sculptures.
- 1 cup water
- 1/4 cup flour
- 5 cups boiling water
- Stir the flour bit-by-bit into one cup of water until no lumps remain.
- Heat the remaining water until it boils. Whisk the flour and water mixture into the boiling water to thicken it into the glue.
- Allow the paper mache paste to cool before using it. It will further thicken as it cools. If it gets too thick, stir in a tiny amount of water to reach the desired consistency.
- If you aren’t going to use the glue right away, add a pinch of salt to discourage mold and store the glue in a sealed container. You can refrigerate paper mache paste to extend its usefulness.
Safety and Clean-up
All of these homemade glue recipes are non-toxic and safe for kids to use. But, some of them require cooking. Be sure to let hot mixtures cool before using the glue.
These glue recipes are water-soluble. Clean any spills with warm, soapy water. The glue won’t stain surfaces unless you add food coloring.