Another Dry Ice question

[JohnHartman]

A question to all of you out there.

I have a Dry Ice fogger I pulled together for the witch sequence in Oz. However I do not have a lot of time testing how much ice I will lose once the effect is prepped. It is a community theatre so i am going to prep the effect at intermission and then cue it at the scene.

My question is how much of the dry ice can I expect to lose over say a half hour. The ice will be in a small bucket hanging 6" over heated water. The water will not be getting continually heated during this time, and I am only looking for a short screen to cover the witch disappearing.

Thanks in advance for any insight

- John

 

[seanandkate]

Single block, or a number of pieces? I ask because it sounds like you want a bunch of fog quickly (so you would want the ice in pieces) but that will make it sublimate more quickly as you wait for the cue).

 

[WooferHound]

The water will not be getting continually heated during this time, and I am only looking for a short screen to cover the witch disappearing.
- John

It's hard to understand what you mean here but, you will want the water to be as hot as possible to make the effect work.

 

[gafftaper]

It's hard to say as a lot of it depends on your fogger. They are all a little different, especially, if it's one you built. There's no way to know without testing it.

I say find a way to have a stage hand put the ice in the machine 5 minutes before it's needed.

 

[kiwitechgirl]

I'm with Gafftaper - load the ice as late as possible. From memory, there's quite some time between interval and the witch-melt and you're likely to need a big quantity of ice to allow for what you'll lose. I've done my fair share of shows as stage electrician, and I've always loaded the ice just before the effect was required.