colored smoke from a machine

[Tim O'Connor]

Has anybody ever used anything in a fog machine that produces any color fog/smoke other

than the regular white color? I have a bunch of inexpensive fog/smoke machines and was wondering if there is anything available or if anybody has ever experimented with adding something for color to the regular fluid.

[Phil Rhodes]

Short answer: no. Long answer: noooooo.

 

There are basically two ways of making coloured smoke. First is pyrotechnically, which is how distress flares and military marker grenades do it. This approach works by using a fairly low-powered pyrotechnic composition which burns at a very controlled temperature and evaporates a solid block of dye, so the cloud of coloured smoke you see is made of comparatively large particles and behaves rather like a cloud of dust.

 

The other approach is the way aircraft (particularly military jet aircraft) do it, which is to spray a relatively heavy fuel oil (such as diesel) into the hot exhaust. Colour is produced by dissolving dye in the diesel, which precipitates back out into the air when the diesel is evaporated.

 

Both of these solutions end up producing a broadly similar result - all true smoke is a cloud of solid particles, and they just ensure that the solid particles are coloured appropriately. Unfortunately, this means that in both cases the smoke is toxic, or at least not entirely safe to breathe, because of the nature of the dyes and associated diesel smoke or pyrotechnic discharge. They are also incredibly messy, as the particulate dye tends to settle on any object it touches like a fine, greasy dust. To get a density sufficient to make the colour readily observable, you end up using a very large proportion of dye to carrier and you don't have many choices of dye as few will stand the heat of evaporation without losing their colour, and they must be very dense.

 

Experiments have been done in attempts to dye smoke oil for effects work, without any success I've heard about. It's easy to destroy the machine, but you'd also have to prove somehow that the results were as safe to breathe as normal smoke oil.

[Tim O'Connor]

Short answer: no. Long answer: noooooo.

 

There are basically two ways of making coloured smoke. First is pyrotechnically, which is how distress flares and military marker grenades do it. This approach works by using a fairly low-powered pyrotechnic composition which burns at a very controlled temperature and evaporates a solid block of dye, so the cloud of coloured smoke you see is made of comparatively large particles and behaves rather like a cloud of dust.

 

The other approach is the way aircraft (particularly military jet aircraft) do it, which is to spray a relatively heavy fuel oil (such as diesel) into the hot exhaust. Colour is produced by dissolving dye in the diesel, which precipitates back out into the air when the diesel is evaporated.

 

Both of these solutions end up producing a broadly similar result - all true smoke is a cloud of solid particles, and they just ensure that the solid particles are coloured appropriately. Unfortunately, this means that in both cases the smoke is toxic, or at least not entirely safe to breathe, because of the nature of the dyes and associated diesel smoke or pyrotechnic discharge. They are also incredibly messy, as the particulate dye tends to settle on any object it touches like a fine, greasy dust. To get a density sufficient to make the colour readily observable, you end up using a very large proportion of dye to carrier and you don't have many choices of dye as few will stand the heat of evaporation without losing their colour, and they must be very dense.

 

Experiments have been done in attempts to dye smoke oil for effects work, without any success I've heard about. It's easy to destroy the machine, but you'd also have to prove somehow that the results were as safe to breathe as normal smoke oil.

 

 

Hi Phil, thanks for the detailed answer. For the sake of discussion, what do you suppose is it in the glycerol based food-additives that, along with the de-ionized water which are the listed ingredients in my fog juice, gives the fog/smoke its white color? I'll bet somebody must have leapt from reading that to running some food coloring through one of these.