This method is safe for kids to follow on their own, and much faster and easier than making a permanent lava lamp. Young kids can ask an adult to do the pouring for them.
Any other tablet labeled “effervescent” will work. These are often sold as Vitamin C tablets at drugstores.
Add more salt or another effervescent tablet whenever the blobs start moving.
Salt sinks down to the bottom of the bottle, dragging a blob of oil with it. Once the salt breaks up and dissolves in the water, the oil floats up to the top again. [4] X Research source The fizzy tablet reacts with the water to make tiny bubbles of carbon dioxide gas. These bubbles attach themselves to the blobs of colored water and float up to the surface. When the bubbles pop, the colored blobs sink back to the bottom of the bottle.
Commercial lava lamps use a proprietary combination of melted waxes. The homemade version doesn’t achieve exactly the same look, but after some tweaking your “lava” should bob up and down in similar, gooey glory.
Starting with plain oil for your first attempt is a good idea, but you can mix in artist’s oil paint first if you want colored “lava. " Be aware that the paint might separate later, gathering on the top or bottom of the jar.
Mix together 6 parts 90% alcohol and 13 parts 70% alcohol. [6] X Research source (You can estimate this by filling a small cup with 90% alcohol once, then 70% alcohol twice, then pouring in an extra dash of 70%. ) Pour this into the jar and wait for the liquid to settle. The oil should end up on the bottom, but bulge upward slightly in the center. If it looks flat, you can pour in slightly more 70% alcohol, but you don’t need to get it perfect at this point.
Select an incandescent bulb carefully. For a jar 12 ounces (350 mL) or smaller, use a 15 watt sewing machine bulb. Larger containers can use a 30 watt or 40 watt bulb, but never higher-powered ones, due to the risk of overheating or shattering the glass. Place this bulb in a small, directional lamp below the jar, pointing upward. For maximum control over the light and heat, install a dimmer switch on the lamp.
Try rotating the lamp gently once in a while as it warms up, using a cloth or oven mitt to touch it. Don’t leave the lamp on when you leave the room, and turn it off to let it cool after a few hours of being on, at most.
Stir in a few spoonfuls of salt water to increase the density of the alcohol mixture. Shake the lava lamp gently to separate the oil into smaller blobs. Don’t overdo this, or you’ll end up with sludge instead of lava. If the oil has separated into tiny balls, mix in a spoonful of turpentine or other paint solvent. These are dangerous chemicals, so don’t try this if the lamp is reachable by children or pets.
