Craft Fog

OUT OF ALL the special effects I’ve needed over the years, low-lying fog may be the most versatile and popular. I’ve used it to enhance everything from the dream ballet in Oklahoma! to the dragon’s lair in Shrek.

Depending on your purposes, stage fog can express enchantment or gloom, it can veil a transformation or rise as smoke. For this article, I will focus on fog that hangs out low to the ground. Stage fog is often achieved with machines that heat fog fluid into a vapor that is warmer than the surrounding air and therefore rises. On the other hand, low-lying fog must remain colder than the surrounding air. For that, you need a fog cooling device in addition to your regular fog machine.

There’s a seemingly endless number of commercial fog coolers on the market that achieve this effect. Many come with steep price tags, and of course, the price of the fog cooler itself is just one cost. Every method for cooling fog requires something expendable that must be purchased for every performance, such as CO2 or dry ice. These costs can add up quickly and should be considered when determining which overall fogging method fits your budget and needs.

The following may be the most cost-effective way to get fog to stay on the ground. With this device, you can create low-lying fog using your regular fog machine and an ordinary drink cooler — with some simple modifications. This will work with any fog machine, but the better the fog machine, the better results you will have.

WHAT YOU NEED

• Regular fog machine
• Fog fluid
• Drink cooler (a 48-quart cooler works great and can be purchased for around $20)
• (2) 2″ schedule 40 PVC adapters (slip x thread) female — Lowe’s #23906
• (2) 2″ schedule 40 PVC adapter (slip x thread) male — Lowe’s #23904
• Piece 1/4″ x 1/4″ wire mesh hardware cloth (usually in the home and garden section)
• (2) 2-1/8″ to 3″ hose clamps — Lowe’s #62089
• Hole saw with 2.5″ bit
• Black spray paint
• Black magic marker
• Safety glasses
• Gloves

HOW TO MAKE IT

First, mark the location of the hole on both sides of your cooler — centered about 3.5″ from the bottom.

Next, don your safety glasses and gloves, then drill through your marks with the 2.5″ hole saw bit.

Then, insert the PVC fittings into each drilled hole and tighten. My cooler wall was thicker than the length thread on the PVC fitting, so I had to trim some outside plastic to allow the fitting to be inset into the wall of the cooler.

Next, cut a piece of the hardware cloth to the length of your cooler by 10″ wide — always wear gloves while cutting and handling this wire mesh. Bend the mesh into a cylinder and attach it to the PVC fittings using the hose clamps. This tunnel will give the fog a clear, unobstructed path through which to pass from one end of the cooler to the next. Finally, feel free to give it the official backstage look by spray-painting it black.

Congratulations! You now have a fog cooler.

Mark the location of the hole on both sides of your cooler, centered about 3.5" from the bottom.

Don your safety glasses and gloves, then drill through your marks with the 2.5" hole saw bit.

Insert the PVC fittings into each drilled hole and tighten. My cooler wall was thicker than the length thread on the PVC fitting, so I had to trim some of the outside plastic, allowing the fitting to be inset into the wall of the cooler.

Cut a piece of the hardware cloth to the length of your cooler by 10" wide (always wear gloves while cutting and handling the wire mesh). — Cut a piece of the hardware cloth to the length of your cooler by 10" wide (always wear gloves while cutting the wire mesh).

Bend the mesh into a cylinder and attach it to the PVC fitting using the hose clamps. This tunnel will give the fog a clear, unobstructed path through which to pass from one end of the cooler to the next.

HOW TO USE IT

First, fill the cooler with ice — either normal ice, dry ice, or a combination of both. I’ll discuss the positives and negatives of normal ice versus dry ice in a moment. You will want enough ice in the cooler to completely surround and cover the wire tube.

Next, insert the nozzle of your fog machine into one of the PVC fittings on the end of the cooler. Now, the fog that your fog machine emits will pass through the cooler via the wire tunnel. The ice surrounding the tunnel will cool the fog, so that after it leaves the cooler, it will creep along the ground.

NORMAL ICE VS. DRY ICE

Normal ice is the cheapest and easiest to get. At our school, the athletic department keeps an ice machine for icing injuries, so we have plenty on hand. The downside is that normal ice melts more quickly — and more messily. Still, most of the time, I use normal ice because of its price, convenience, and relative safety.

Place a towel in the bottom of the cooler to help soak up the melt water and another underneath the cooler. Empty the cooler as soon as possible after each use, to avoid water leaking out of the two holes that you put in the cooler.

Dry ice provides a much colder fog that will stay lower for longer, and it leaves no liquid because it sublimates (that is, changes to gas) rather than melts. However, it is more expensive and more difficult to obtain — and also more hazardous. There is no safe, easy way to store dry ice, so it must be purchased just before each performance. Don’t forget to check the store hours, so you don’t end up surprised by a closed store before your Sunday matinee!

Always wear gloves when handling dry ice, as it can cause severe frostbite on contact. Also, dry ice must be stored and used in a well-ventilated, room-temperature location. Be sure to transport dry ice in the trunk of your car, away from the driver and passengers. Finally, dispose of dry ice by letting it entirely sublimate in the cooler, under your supervision and in a safe, well-ventilated space without a lot of foot traffic. Never throw it in the trash, sink, or toilet, and do not let it touch tiled or solid surface countertops, as it can damage these materials.

Regardless of the fog fluid and ice you use, low-lying fog can create condensation on stage, which can be slippery. This typically occurs only where the fog exits the cooler. Position your fog machine and cooler far enough off-stage to avoid a safety hazard and train your actors to step mindfully through stage fog. Wipe down the stage carefully after each performance.

Now, you’re ready to create atmospheric magic onstage. This technique saves money and produces a safe and durable way to keep your fog at the actors’ feet and impress your audience every time.

Happy fogging!

This story appeared in the April/May 2018 print issue of Dramatics.