Kinetic Sand Recipe

Kinetic sand is sand that sticks to itself, so you can form clumps and mold it with your hands. It's also easy to clean up because it sticks to itself.

Kinetic sand is an example of a dilatant or non-Newtonian fluid that increases its viscosity under stress. You may be familiar with another non-Newtonian fluid, oobleck. Oobleck resembles a liquid until you squeeze or punch it, and then it feels solid. When you release the stress, oobleck flows like a liquid. Kinetic sand is similar to oobleck, but it is stiffer. You can mold the sand into shapes, but after a few minutes to hours, they will flow into a lump.

You can buy kinetic sand in stores or online, but it's a simple and fun science project to make this educational toy yourself. Here's what you do:

Kinetic Sand Materials

• Fine play sand
• Dimethicone [polydimethylsiloxane, CH₃[Si(CH₃)₂O]_nSi(CH₃)₃]

Use the finest sand that you can find. Fine craft sand works better than playground sand. You can experiment with colored sand, but be aware the dyes may not work for the project.

Kinetic sand that you buy in the store consists of 98% sand and 2% polydimethylsiloxane (a polymer). Polydimethylsiloxane is known more commonly as dimethicone, and it is found in hair anti-frizz gel, diaper rash cream, a variety of cosmetics, and in pure form from a cosmetics supply store. Dimethicone is sold in different viscosities. A good viscosity for this project is dimethicone 500, but you can experiment with other products.

How to Make Kinetic Sand

1. Spread dry sand out in a pan and allow it to dry overnight, or place it in a 250 F oven for a couple of hours to drive off any water. If you heat the sand, let it cool before proceeding.
2. Mix 2 grams of dimethicone with 100 grams of sand. If you want to make a bigger batch, use the same ratio. For example, you would use 20 grams of dimethicone with 1000 grams (1 kilogram) of sand.
3. If the sand won't stick together, you can add more dimethicone, a gram at a time, until you get the consistency you want. Homemade kinetic sand is similar to what you would buy, but the commercial product uses super-fine sand, so it may behave a bit differently.
4. Use cookie cutters, a bread knife, or sandbox toys to shape the kinetic sand. 
5. Store your sand in a sealed bag or container when you aren't using it.

Recipe for Homemade Kinetic Sand Using Cornstarch

Cornstarch is the material mixed with water to make oobleck and ooze. If you can't find dimethicone or are looking for a cheaper alternative, you can make homemade kinetic sand that is essentially oobleck with sand. It will not be as easy to mold as dimethicone sand, but it's still fun for younger explorers.

The advantage over regular play sand is that this recipe will stick together, so you can have an indoor sandbox without tracking as much sand all over your home.

Materials

• Large plastic tub or a small pool
• 6 cups cornstarch
• 6 cups water
• 50-lb bag of play sand

​​Instructions

1. First, make the oobleck by mixing the corn starch and water.
2. Stir in the sand until you get the consistency you want. It's okay to add a bit more of any ingredient to get the perfect sand.
3. If you like, you can also add a squirt of dishwashing detergent or a couple of spoonfuls of tea tree oil to help prevent bacteria or mold from growing on the sand.
4. The sand will dry out over time. When this happens, you can add more water.