How to Make a Real Lava Lamp

A lava lamp is a terrific advanced chemistry project!
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There a recipes all over the internet for easy lava lamps, but they aren't the real deal. That's because true lava lamps are a bit trickier to make. If you're ready for the challenge, here's what you do.

Lava Lamp Materials

How to Make the Lava Lamp

  1. Break open an oil-soluble marker or pen and place the inked felt into a container of benzyl alcohol. Leaving it in longer will give a darker color, but will also increase the tendency to bleed into the brine.
  1. A few minutes is usually a good time to leave the inked felt in the alcohol. A Sharpie bleeds too much into the brine, so choose a different type of marker.
  2. The benzyl alcohol, specific gravity 1.043 g/ml, and 4.8% salt water (brine, specific gravity 1.032 g/ml) go into the glass container. A bottle about 10 inches tall is good.
  3. Build a base to hold the bottle over the lamp using a tin can and plywood. A dimmer on the light will allow you to control heat.
  4. You may wish to place a fan at the top of the bottle to cool the liquid at this location.
  5. You will need to experiment to get the best distance between the heat source (light) and the glass container.
  6. You want about 150 ml benzyl alcohol and the remainder of the liquid to be brine. Seal the bottle, but allow air space.
  7. Try about 1 inch of air space at the top, to allow for expansion of the fluids. The amount of air space will affect bubble size.
  1. Responsible adult supervision is required! Because the materials may be toxic and there is a flammability hazard, this project is not intended for young or inexperienced investors.

Tips for Success​

  1. Alternatives to benzyl alcohol include cinnamyl alcohol, diethyl phthalate, ethyl salicylate, or nitrobenzene.
  1. An oil-based ink may be used instead of the marker.
  2. If the benzyl alcohol floats to the top and stays there, add more water. If the alcohol stays at the bottom, add more salt (NaCl).
  3. A trace amount of an antioxidant, such as BHA or BHT, may be added to the liquid to add color and increase contrast.
  4. Please read the Material Safety Data Sheet for benzyl alcohol before performing this procedure. Have fun and be safe!