Burst Smoke Effect

[SargeB96]

Anyone know the best way to make a smoke/steam like burst? I'm wanting to build a sort of sanitation room that characters get gassed/ sprayed at with smoke/ steam whatever.

I thought a smoke machine might work, but I feel that it wouldn't clear away that quickly (unless I put a suction fan under the floor of the set)

This the best way or do you know of any others? If you want an example, the one in Small Soilders clean room is the one I'm thinking of.

 

[propmaster2000]

Are you looking for repetitiveness and for many, many uses?
Remote activation or close-up triggering of the effect?
Any information you can share will help in finding something that will work for you.
"Smoke in a Can" is the quick and easy way for occasional FX.

.

 

[TazMan2000]

I think there is a way that forces regular water through a very fine filter to produce this effect,

TazMan2000

 

[SargeB96]

Well, since this is for film, I'd like to be able to use it over and over for each take and remote would be best. What I'm looking for is to have a burst of smoke or steam or something like it to come from the roof and sides of this small room which is as if the characters are walking into a sanitized area, like a electronics clean room or a hazmat room

 

[propmaster2000]

.
Since this is for a film effect, you have a bit of leeway in case it doesn't work well a few times....
I feel you would need something that has a bit of pressure behind it as it sprays the smoke, steam, powder, Co2, etc.
Sometimes Escape rooms use a blast of smoke/gas as an effect.

I guess you would have to look at the "after effect" as well and what would be left behind.
Powders/chemicals would not be practical. They leave a residue.
Steam vapor and Co2 may cause moisture. A Co2 extinguisher would produce a nice " blast" if it was piped
to different areas with tubing.

The valve on a small extinguisher could be rigged with a solenoid style electric plunger to press and release the handle.
If you had a few placed around the set, they could be activated at the same time.
If you go with the canned smoke, the same can be applied to them as well. An electronic solenoid style plunger.
Maybe 12v door lock actuator could be used to "lever" the handle or press the button on a can.
https://www.allelectronics.com/item/dla-1/door-lock-actuator/1.html

There would need to be a way to direct the smoke in a can straight out though a small tube. Like WD40 has the tube.
Just thinking out loud

.

 

[Scapey]

CO2 is your best bet.
You can get small bulbs for air pistols, or bigger ones for soft drinks machines quite cheaply.
For the valve itself, fast-inflators for bicycles are handy:
https://www.tweekscycles.com/Produc...tDnQV9ERLPdPN4KP7xBoC6EQQAvD_BwE&gclsrc=aw.ds

 

[SargeB96]

Wouldn't I need a special solenoid and hose for working wi5h high pressure co2?

 

[robstyle]

Having done the "clean room" and Halon system effect before, the easiest and most fail proof way to go about it is simple Co2 fire extinguishers. Youll need to fabricate an enclosed system housing the head of the extinguishers all the way along the areas that are to release the Co2. Its not as complicated as it sounds and not something to over think. If its a doorway, youll need to build the entire doorway and bulkhead. If its from the ground youll need to build a raised surface floor, if its from the ceiling.... Its trial and error but nothing that will take more than an hour to perfect once the main set piece is constructed. Vents vs holes for the Co2 to escape is what you want to play with. Youll want a wider and larger inner cavity area the further away from the extinguisher nozzle source point. In other words if youre doing an entire doorway, split it in half with one Co2 extinguisher on each side. From the top down youll start with an opening just large enough for the nozzle getting larger towards the ground. This allows the Co2 to fill the cavity more evenly as it disperses itself out of the vents/holes for the effect. You may or may not need a third canister to act as the top doorway filler. Its a two person job with a third watching from monitor. Its also a safety heavy gag as the actors involved will have to close their eyes and keep them shut before, during and just after the gag as well as hold their breath. Its a very simple gag though.

As back up you can have smoke machines filling bladders made from tarps and visqueen. The tarps act as the protective barrier jacket between the visqueen and any potential sharp edges. Youll basically need to pop pre scored and taped flaps using a fan or other pressure source to make the smoke flow. Its easier to figure out on hand than it is to try and type out. If you need the smoke to fall, run it through a cooler with a block of dry ice in it. This keeps the smoke itself cold and heavy and is typically how ground cover is done. If using the smoke effect, consider the use of a hazer as well for atmosphere effect. Once that smoke rises after a couple uses, its either take five and blow the place out or keep going as haze has already been established. Its pending your studio location however if its even possible to air the set out in five minutes.

 

[McFlyte]

For those that have used CO2 for this, is there any safety concern with it displacing enough oxygen to cause ill effects? Not trying to rain on your parade as it seems the most convincing option, just curious as I've never played with CO2 extinguishers before.

 

[robstyle]

Ive never had any issues using Co2 extinguishers before. In fact we fully discharge them after each week of on set use. It dissipates quickly in both indoor and outdoor locals.