Two Ways to Make Waterproof Magic Sand

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Magic sand is waterproof sand that appears dry when removed from water.
Magic sand is waterproof sand that appears dry when removed from water. (photo: Castorly Stock)

Magic Sand is waterproof or hydrophobic sand that doesn’t get wet when poured into water. It’s sold as a children’s toy as Magic Sand, Space Sand, or Aqua Sand, but the product has been around for a long time. The 1915 book The Boy Mechanic Book 2 references the sand and says it was invented by East Indian magicians. Here are two ways to make homemade magic. One uses the original recipe, while the other incorporates some modern chemistry.

Make Homemade Magic Sand – Method 1

The original method to make magic sand is coating sand with wax.

  • Clean sand
  • Wax (or even bits of crayons)
  • Cookie sheet or bowl covered in foil
  • Spoon you don’t mind coating with wax

All you need to do is mix together melted wax and sand. On a hot summer day, you could place the pan, wax, and sand on a sidewalk to make magic sand. Otherwise, pour sand and a small amount of wax onto a covered baking sheet and heat it in the oven on a low temperature until the wax melts. Carefully remove the pan, stir the wax and sand until the sand is coated, and let the sand cool before use.

Make Homemade Magic Sand – Method 2

The modern method of making magic sand involves spraying play sand with a waterproofing chemical. It’s best to work outdoors or in a well-ventilated area, as the Scotchguard fumes are pretty strong.

  • Clean sand
  • Waterproofing spray (such as Scotchguard)
  1. Coat a cookie sheet or bowl with foil or plastic wrap. You can omit this step if you don’t mind Scotchguarding your container.
  2. Spray the sand surface with Scotchguard.
  3. Shake the container or use a disposable spoon to expose untreated sand.
  4. Repeat the spraying process until all of the sand is coated. Freshly coated sand appears wet.
  5. Allow the sand to dry before using it.
  6. Pour the sand in water and it won’t get wet!

Magic Sand Activities and Clean Up

Of course, the first activity is to pour some sand into a container of water. See how it appears to change color and glisten like metal? Use a spoon to scoop up the sand in the water and remove it. It’s dry!

Make a Magic Sand Tower

  • Roll a sheet of paper into a tube.
  • Hold the tube upright in an empty bowl, so it’s touching the bottom.
  • Pour magic sand into the tube.
  • Pour water into the bowl so it’s almost to the top of the tube.
  • Loosen your grip on the paper tube so it unrolls slightly and lets water in. Then lift the tube out of the bowl, leaving a column or tower of magic sand.

Make Sand Cakes

  • Use a funnel (or make one using a small sheet of paper) to pour a small mound of magic sand into an empty bowl.
  • Pour water down the side of the bowl until the water level is almost to the top of the sand mound.
  • Use the funnel to add another sand mound on top of the first.
  • Again, pour water down the side of the bowl until it almost reaches the top of the mound.
  • Repeat the process to make a stack of sand cakes. Don’t eat them!

Storing Magic Sand

You can use magic sand again and again. When you’re done playing, pour off as much water as possible. Place the sand on paper towels to dry. Once it’s dry, pour it into a plastic bag or jar to use another day.

How Magic Sand Works

Magic sand works because of chemistry, not magic. First, coating the sand seals pits or cracks, preventing water from sticking to it. Second, the coating is hydrophobic, which means it repels water. The nature of the hydrophobic coating depends on the type of magic sand. Magic Sand, Space Sand, and Aqua Sand are colored sand coated with trimethylsilanol ((CH3)3SiOH). The methyl groups act as a barrier between the sand (or any silicate) and repel water. Wax also fills in defects in sand particles and is an organic compound that repels water. Scotchguard also contains a hydrophobic chemical, although which chemical it is depends on the age of the can of Scotchguard. Originally, Scotchguard contained perfluorooctane sulfonate (PFOS), but it was replaced by perfluorobutanesulfonic acid (PFBS) in 2003 because of health and environmental concerns.

When you pour magic sand in water, it appears silver-colored, no matter what color the original sand appeared. This is because hydrogen bonding between water molecules produces bubbles around the sand particles. Basically, water preferentially sticks to itself over the coated sand. But, the anti-wetting property only applies to polar molecules like water and not to other liquids. If you pour magic sand in a nonpolar liquid (like oil), it will get wet and clump together.

See How to Make Magic Sand

This video shows how to make magic sand using Scotchguard. While it does a great job of showing what to expect, it’s probably a good idea to coat the sand by shaking the pan or stirring it with a disposable plastic spoon or gloved hands rather than bare hands. Otherwise, you’ll Scotchguard your hands, which isn’t all that fun (voice of personal experience).

Safety Information

If you buy magic sand, it’s safe for kids to use. However, adult supervision is needed if you make it yourself because you’ll either use heat (wax method) or spray chemicals (Scotchguard method).

References

  • G. Lee, Leonard (Publisher) (1999). The Boy Mechanic Book 2, 1000 Things for a Boy to Do. Algrove Publishing – Classic Reprint Series original publication 1915. Popular Mechanics.
  • Grubb, W.T.; Osthoff, R.C. (1953). “Physical Properties of Organosilicon Compounds. II. Trimethylsilanol and Triethylsilanol.” J. Am. Chem. Soc. 75: 2230–2232. doi:10.1021/ja01105a061
  • Ullah, Aziz (October 2006). “The Fluorochemical Dilemma: What the PFOS/PFOA fuss is all about.” Cleaning & Restoration.