If you grew up in the 1960s or the 1990s, I’m pretty sure that you’ll have owned a lava lamp at some point, or at least knew somebody that did.
After their invention in 1963, these psychedelic decorations quickly became a bedroom essential across the globe. Even after all of these years, both children and adults continue to purchase trippy, liquid motion lamps.
However, despite their immense popularity, lava lamp technology is seldom understood.
Governments around the world have sought to ban inefficient light sources. This has led to one pivotal question: do lava lamps work with LED bulbs?
LED bulbs cannot be used in lava lamps because they do not generate a lot of heat. As an energy-efficient light source, LEDs do not get hot enough to melt the wax blobs inside of lava lamps. Essentially, this means that the wax will remain static and will not move around.
In their prime, lava lamps were being sold at a rate of around 7 million per year! But with new restrictions on inefficient light sources, are lava lamps set to die out forever?
Keep reading to learn more about how lava lamps work, what kind of bulbs they require, and how to replace broken lava lamp bulbs.
What Are Lava Lamps and How They Work?
Unless you’ve been living under a rock, you probably already know what a lava lamp is.
Although they come in various shapes, colors, and sizes, the fundamental components remain the same. A glass globe contains two compounds: a transparent, water-like material and an opaque, wax-like material.
At the base of the lamp is a light bulb, which simultaneously illuminates and heats the globe. In turn, the amorphous wax blobs continuously move around, creating a relaxing yet psychedelic effect.
They’re pretty simple devices, but manufacturers are notoriously tight-lipped about their ingredients. It’s assumed that the transparent liquid is a mixture of distilled water, alcohol, and salt. The lava, whereas, is a blend of paraffin and perchloroethylene.
At this point, you may be thinking: “what causes the wax compound to move around inside the globe?”. Let me explain.
Just like oil and water, the two compounds found inside lava lamps are immiscible. This means that they’re mutually insoluble, so liquid A doesn’t dissolve in liquid B.
But that’s not all, the compounds are also very close in density. Paraffin wax has a relative density of approximately 0.9 kg/m3, and alcohol has a relative density of around 0.8 kg/m3.
When a lava lamp is switched on, the bulb heats the bottom of the immiscible mixture. The denser compound (the wax) absorbs the heat and starts to expand.
As it expands, its molecules spread apart, making it less dense. The wax compound is now lighter than the surrounding alcohol compound, so it rises to the top of the globe.
However, the wax is further away from the heat source at the top of the globe, so it cools down and becomes denser. As it becomes heavier, the wax sinks to the bottom of the globe. This cycle continues indefinitely.
The density variations are tiny, but they are enough to make the wax alternatively rise and sink.
Why Are LED Bulbs Not The Best Choice For Lava Lamps?
Now that you understand how lava lamps work, I’m sure you can guess why LED bulbs are not the best solution.
The short answer: LEDs do not generate enough heat to melt the wax compound.
The majority of lava lamps use 40-watt incandescent bulbs. These bulbs create light by heating a carbon filament to around 4600 degrees Fahrenheit.
As you can see, there’s a lot of heat involved in this process. In fact, incandescent bulbs waste around 90% of their energy as heat, with only 10% of their energy being used to produce light.
Ultimately this means that a 40-watt bulb will produce 36 watts of heat and only 4 watts of light. It is this heat that melts the wax compound, causing it to expand and rise.
In contrast, LEDs are the complete opposite. As an energy-efficient light source, they use 90% of their energy to create light and only 10% is wasted as heat.
Heat is the enemy of LEDs. Most LEDs are designed specifically to dissipate heat through features such as a heat sink or cooling fins. This is because excess heat shortens the lifespan of LEDs, and increases the rate of lumen degradation.
Don’t get me wrong, LEDs do produce heat but it is nowhere near enough to melt the wax compound. Instead, the wax may break into tiny little blobs or remain static in the middle of the lamp.
What Bulb Are The Most Suitable For Lava Lamps?
With that in mind, you may be thinking, “what’s the alternative?”. If LED bulbs aren’t compatible with lava lamps, which bulbs are?
Again, the answer depends on the amount of heat that the bulb produces. Inefficient bulbs, namely incandescents and halogens, are superior in this context. Conversely, energy-efficient lightbulbs such as CFLs and LEDs should be avoided.
Sounds straightforward enough, right?
The problem is, inefficient light sources are gradually being phased out across the globe. This movement initially started in the EU around 13 years ago.
The bottom line is that light bulbs don’t last forever. Incandescent bulbs, in particular, have a short lifespan of just 750 to 2000 hours. So at some point, your lava lamps will require a replacement bulb.
Does the ban on inefficient light sources mean that lava lamps are set to become a thing of the past?
Thankfully not. It seems that lava lamp manufacturers are somewhat of an exception to the rules. Many of them have been allowed to continue producing incandescent and halogen bulbs.
Therefore, if you need a replacement bulb for your lava lamp, my best advice is to start by looking at the manufacturer’s website!
Important: Wattage Needs To Be The Same!
Shopping for a new light bulb can be overwhelming in any context, especially when searching for a replacement lava lamp bulb. The reality is, lava lamps depend on the precise calibration of components, so it’s very easy to get it wrong.
If you only take away one thing from this blog post, make sure it’s this: the replacement bulb needs to have the same wattage as the existing bulb!
As I mentioned earlier, conventional bulbs waste 90% of their energy as heat. Lava lamps are explicitly designed with this in mind.
If a lava lamp uses a 60-watt bulb, the internal wax compound is designed to melt and expand when exposed to 54 watts of heat. Anything else will throw it off balance.
If you replace a 60-watt bulb with a 40-watt bulb, the wax may not get hot enough to melt. Alternatively, if you replace it with a 100-watt bulb, the wax may get too hot and not have the chance to cool down when it reaches the top of the globe.
Lava lamps are a fascinating invention, but it’s fair to say that finding the replacement bulb is much harder than it used to be.
In recent years, manufacturers have started making bases with built-in heaters. So perhaps LED-compatible lava lamps are a possibility after all!
Have you ever tried using an LED bulb in a lava lamp? Was it a success? Let me know in the comments section down below.