Getting a newly married couple to dramatically perform their first dance on a sea of clouds is certainly not a new idea, in fact it has been around since the early days of the mobile DJ industry. It is, however, currently enjoying a bit of a revival. An increasing number of wedding specialist DJs are offering ‘dancing on the clouds’ as an up-sell, promising a truly magical first dance - as well as the resulting epic photos - to their couples.
It’s also often seen in glorious HD on TV shows such as Strictly and The X-factor, which means that clients are usually quite familiar with the plumes of majestic clouds drifting onto the floor. So, as long as you’re a decent salesperson, it’s pretty easy to sell this with your other services. If sparkly LED dancefloors are also part of your arsenal of goodies, you can combine the two effects. When I paint the picture of “romantic stars twinkling through the swirling clouds, resulting in jaw-dropping reactions from all the wedding guests and first dance pictures which are truly astounding” many couples take the bait. I also sometimes jokingly promise to cover up their dodgy dance moves, as the couple’s feet will be hidden from view!
Dry ice, sometimes referred to as ‘Cardice’ (chiefly by British chemists), is the solid form of carbon dioxide. It is extremely cold, as at normal atmospheric pressure CO2 sublimates (transitions directly from a solid to a gas) when its temperature exceeds −78.5 °C. It is colour-less, non-flammable and has a subtle, sour and zesty odour. It is usually available as 3mm or 16mm diameter dry ice pellets or as a solid cube. It’s the 16mm pellets that work best for creating the ‘dancing in the clouds’ effect, which look very much like white Wotsits in size and shape. To manufacture the dry ice, most suppliers use liquid CO2, processed into dry ice snow, and then pushed through a die to make hard dense strands of solid CO2 that break up into random lengths of dry ice pellets on exiting the pelletising machine.
A professional theatrical dry ice machine is actually quite a large piece of kit. If you haven’t seen one in the flesh, imagine a huge deep fat fryer with a big fat spout on the end of it. The machine is plugged into the mains (some models use two elements and have two power cables) and it uses a lot of electricity - so don’t share its power source with any of your other DJ kit, or anything else for that matter! It really is a matter of one plug to one mains outlet on this occasion.
All of this power is used to heat a large vat of water until it almost boils - an indicator will come on to say it’s good to go. This heating process can sometimes take up to an hour, so allow for this when planning your timeline. To speed things up dramatically, use water from the hot tap, or, if there’s a kitchen with a supply of piping hot water then you’ll be in business much sooner. A couple of good watering cans and some smaller jugs (in case the cans don’t fit under the taps) are essential equipment. As well as a good pair of waterproof and heat resistant gloves to handle the dry ice (very cold) and protect you from the boiling water (very hot).
Dry ice ‘machines’ are really quite simple. They involve the aforementioned water tank, a basket for holding the dry ice, and a mechanism for manually lowering the basket into the tank. When this occurs the sublimation of the dry ice is rapidly accelerated creating the distinctive thick clouds of ground-hugging fog.
One important thing to point out is the enormous difference between a real dry ice machine and those imposter products promising ‘low fog’ by flowing the output of a standard smoke machine through a compartment filled with domestic ice cubes. Apart from the dramatic difference in price (just under £1,000 for real dry ice and a fraction of that, as low as £80, for the surrogate machine), the results are completely different and could result in disappointment, upset venues and potentially ruined first dance photos for Mr & Mrs ‘JustMarried’.
All the ‘ice-cube’ machines do is cool normal smoke. This does result in smoke that has a lower temperature than the surrounding air, making it hug the ground initially. However, all it takes is the slightest draught, or someone moving across the dancefloor (a newly married couple for example), and the smoke will swirl all over the place and quickly rise. At this point the effect will turn into that of a normal smoke machine. Even without moving people, the smoke from a ‘low fog’ machine will very quickly warm to room temperature, spoiling the effect. The result will be a disgruntled bride wafting clouds from her face, guests who can’t see the happy couple, and an angry photographer who can’t take that perfect ‘first-dance’ photo. And, to top it all off, the smoke will soon reach the smoke sensor and set the alarms off and you’ll never work at that venue again!
Dry Ice will never set any alarms off, and it will always hug the ground as the CO2 remains heavier than the surrounding air. It’s not the temperature of the clouds that keeps them low to the floor, but the density of the gas. The fog originates from the hot water into which the dry ice is placed. People are often surprised at how luke-warm the clouds are; with the name ‘dry-ice’ they expect a very cold experience. Another big advantage of Dry Ice is that it doesn’t leave any residue (other than rare incidental frost from moisture in the atmosphere, or condensation on some dancefloors - make sure you inform dancers if this is the case).
The full article can be found in Pro Mobile Issue 81, Pages 28-32.