How to Make a Silicone Bouncy Ball
Craft your own ultra-high-bounce silicone crazy ball at home using cornstarch and silicone caulk for hand-grip exercise, stress relief, and active play.
- Read the tools, materials, safety notes, and steps below for free.
- Tap Start Camera Coach when you want hands-free voice help.
- Allow camera and microphone. Point your phone at the work; the coach watches your progress and tells you the next step.
🧰 Required Tools & Equipment
- ✓ Nitrile gloves
- ✓ Caulking gun
- ✓ Disposable plastic mixing bowl
- ✓ Parchment paper sheet
- ✓ Wooden craft stick
- ✓ Measuring cup
📦 Materials & Supplies
- ✓ 100% clear silicone caulk (acetic cure)
- ✓ Cornstarch
- ✓ Liquid acrylic paint or silicone pigment
⚠️ Safety Checkpoints & Warnings
- • Work in a well-ventilated area or outdoors to safely vent strong acetic acid fumes from curing silicone.
- • Wear nitrile gloves throughout the process to prevent uncured silicone from sticking to skin.
- • Keep cornstarch dust away from open flames and avoid inhaling airborne powder.
📋 Step-by-Step Guide (6 Steps)
Prepare the Powder Bed and Workstation
Cover your flat work surface with a clean sheet of parchment paper. Measure approximately 1 cup of cornstarch and pour it into your disposable mixing bowl, creating a wide well in the center of the powder with your craft stick.
- • A smooth layer of cornstarch sitting in the bowl with a hollow depression in the middle.
- • Working directly on an unprotected tabletop where silicone will stick permanently.
Dispense Silicone and Add Colorant
Load the 100% silicone cartridge into the caulking gun and snip the nozzle tip. Squeeze roughly 1/2 cup of silicone directly into the depression of cornstarch, then add 3-5 drops of acrylic paint onto the silicone blob for vibrant coloration.
- • A neat mound of clear silicone sitting in the cornstarch topped with concentrated paint drops.
- • Adding water-based food coloring in large amounts, which causes premature curdling instead of smooth blending.
Fold and Knead the Compound
Put on nitrile gloves and use the craft stick to roll cornstarch over the silicone blob until it is thoroughly coated. Once no longer sticky to the touch, pick up the mass with gloved hands and knead it firmly for 3 to 4 minutes, folding in additional dry cornstarch until it reaches a firm, non-tacky, dough-like consistency.
- • The mass turns uniform in color and texture, completely releasing from the bowl without sticking to gloves.
- • Kneading with bare hands, resulting in difficult-to-remove silicone sticking to skin.
- • Under-incorporating starch, leaving a soft core that will not bounce properly.
Form the Symmetrical Core
Place the kneaded ball between your palms and roll it in rapid, circular motions with firm, even pressure. Continue rolling for 2 minutes to eliminate internal air pockets, seams, and surface crevices, creating a perfectly round spherical shape.
- • A seamless, smooth, perfectly spherical ball with no visible fold lines.
- • Applying uneven pressure while rolling, resulting in an egg-shaped or lopsided ball that bounces erratically.
Smooth the Exterior Shell
Dust your palms with a pinch of dry cornstarch and lightly buff the outer surface of the ball in light circular passes. This seals the outer pores, removes finger impressions, and accelerates the outer moisture-curing shell.
- • A silky, matte-finish exterior that holds its spherical geometry without sagging.
- • Using water to smooth the surface, which causes localized bubbling and weak spots.
Cure, Wash, and Test Rebound
Rest the ball on parchment paper in a dry, ventilated area for 2 hours until fully rubberized throughout. Once the vinegar odor is completely gone, rinse the ball under cold tap water to remove surface starch residue, pat dry, and test its rebound elasticity on a hard floor.
- • The ball feels firm, highly elastic, completely odorless, and rebounds sharply off hard surfaces.
- • Testing or squeezing the ball before the core fully cures, permanently deforming the sphere.
Credit: inspired by an original tutorial by Hack and Experiment — watch the original on YouTube.
Don’t have everything?
- No Caulking gun? Handheld squeeze tube of 100% silicone sealant
- No Parchment paper? Silicone baking mat or smooth plastic wrap taped flat