Liquid Lamps

Something in the Air A connected pump gives the lights a funky bubbling effect. Luis Bruno

When you're a performance artist, creating the right ambience in your show is everything. It all starts with lighting. So two years ago, my partner and I decided to build a lamp that would capture the aquatic theme of a show that our company, Radiohole, was putting on. We wanted to make a lightbulb look like it was submerged in water, so we used mineral oil, a liquid that's clear and nonconductive (we spilled a lot of oil before finally hitting on a fixture that was both portable and leakproof).

We were also looking for a dynamic effect, so we ran a pump from a fish tank to blow bubbles in the oil, making it look as if it's boiling from the bulb's heat. The final design of the lamps wound up looking so good onstage that many people asked us about getting them for their homes. All the parts to build them yourself are available at home-improvement and electrical-supply stores. If you'd prefer to remain a spectator, though, you can order finished ones at radiohole.com.

Materials

All of these, except the aquarium air pump, can be obtained from McMaster-Carr, for convenient one-stop web shopping. All told it's about $75 in materials.

A vapor-tight fixture with a half-inch hub. This is an industrial fixture, made from cast aluminum and used for outdoor or hazardous locations. It has rubber seals between the various parts to keep moisture out. In our case, we are using the seals to keep the mineral oil in. There are various styles and colors. These can be obtained at an electrical supply store or, like everything else here, over the internet. The price is around $40. Here are some examples of styles and prices.

A basic air pump, the kind used to aerate an aquarium. Price: around $8.

Clear quarter-inch PVC tubing. This can be obtained at the same place you get the air pump. Some pumps come with the tube. 25 feet will run about $2. The length depends on how far the pump is from the fixture. We've run lines up to 40 feet.

A length of three-wire 18awg SJOOW cord. Around $0.55 a foot. You could use any kind of 18awg wire, but we like to use SJOOW cord because it has a strong, flexible neoprene jacket and we like the look of it. Again, the length is up to you.

Nylon liquid-tight strain relief with flex fitting. Be sure to get the half-inch NPT thread, to match the threads on the fixture. This is McMaster-Carr part #69915K63, around $3.25.

• A 3-prong male plug.
• A couple of 18awg wire nuts
• Light-viscosity mineral oil. Mineral oil is a clear, odorless, and most importantly for us, non-conductive liquid. A pint costs around $11. We get it from McMaster-Carr (part # 3190K291).
• A colored clear 25-watt bulb -- the color is up to you.

Tools

• Drill with a 9/32 bit
• Screwdriver
• Wire strippers
• Utility knife

See page two for detailed assembly instructions.