need puff of smoke in cauldron

[Sivy]

Hi, I am sure this question has been asked before, but I couldn't find the answer in the search.

I need an easy way for creating a puff of smoke when something is thrown in a cauldron.

We are doing a Crucible production and in the beginning the "kids" are throwing things into a cauldron I want a puff of smoke to appear.

We dont have much money... like... nothing. Need an easy chemical reaction to produce it. I have checked many science sites. And it has not helped... if anyone can give me tips, I would be very thankful.

Also we cant get dry ice... at least not yet

 

[derekleffew]

These threads http://www.controlbooth.com/forums/special-effects/12551-small-mushroom-cloud.html , http://www.controlbooth.com/forums/special-effects/15769-burning-down-house-well-hopefully-not.html , http://www.controlbooth.com/forums/special-effects/22322-creating-smoke.html , http://www.controlbooth.com/forums/special-effects/5684-bubbling-water-smoke.html didn't help? I'm not sure there is a chemical reaction that will produce safe smoke.

 

[BillESC]

Consider using gerbs. (electric matches)

 

[Sivy]

thanks for the replies. but it didn't really help. I am in Israel. Buying machines that do things would be to expensive for delivery. Anyways, will be poping by for other things. Thanks everyone

 

[headcrab]

Use compressed air. Blow air at a low pressure through a pipe containing flour of some kind.

We did this for our performance of Macbeth. In the cauldron there was a reservoir (2" pipe, 24" long) which we charged with shop air. There was a lawn sprinkler solenoid valve which, when opened remotely, discharged the reservoir through a vertical tube. Someone on set crew would put some rye flour into the vertical pipe, the actresses would stomp on the power button, and we'd get a nice jet of smoke out of the cauldron.

I told them to do the effect with rye flour instead of using pyro.

 

[cprted]

Consider using gerbs. (electric matches)

A gerb, though it will produce some smoke, is a sustaining spark effect, not a smoke effect. Using a gerb in a cauldron to create a smoke effect is inappropriate and potentially dangerous.

There are simple pyrotechnic solutions, but you need to be licensed to use them.

 

[FatherMurphy]

The flour idea might be the easiest/cheapest route to go, but use a hand bellows or foot pump instead of a solenoid valve. Load the powder in the end of a tube, bellows on the other, and see what you get (might need a separate system for each puff, unless you're able to use a hopper big enough to hold several shots worth of powder). You should try to use a powder that is non-flammable, otherwise you could potentially create a small grain dust explosion.

A beekeeper's smoker might be a useful route as well (insert fire-on-stage warning here). Incense cones throw off a lot of smoke when first lit, that combined with a bellows or fan blade might work.

A non-burning version might be to use a fake torch flame style effect, colored silk blown up by a fan, and lit from below. Make the silk larger and differently colored, and see if the fan can push it up fast enough to look effective (the fabric will drop back in when the fan stops).

 

[sk8rsdad]

Try Fullers Earth instead of flour. In the right concentration flour is highly combustible. Google "grain silo explosion" for hours of amusement. Fullers earth is inert and readily available as kitty litter.

 

[Sivy]

thanks everyone for the replies, all of the ideas that were written down here were great! lucky though, we got the universities science department to donate 3 kilos of dry ice... yay! anyways, I will be sure to try out these ideas anyways, who knows when I might actually have to use them.

 

[gafftaper]

You are going to have a hard time controlling that dry ice cloud to make it do what you want. I would go with the flour and some sort of simple hand controlled air powered solution (like a squeeze bottle).

Rye flour is the safest choice.

 

[Sivy]

yea, its not going to have the effect I want, but we have to make sacrifices

 

[gafftaper]

Having messed around with dry ice over the years I find that it's the first thing everyone wants to try because it's just so much fun to deal with. But in reality it often doesn't create the effect they want or is just far more difficult to deal with than other approaches. It's great that you got access to dry ice, but if I understand you correctly the air blown flour approach will create the effect you want and be much simpler to setup and deal with during the show. So you don't have to make sacrifices, other than the fun of playing with dry ice.