building dry ice fog machine

[icewolf08]

Originally Posted by gafftaper

Alex, when you did it did you use any dry ice?

We didn't use any Dry Ice fog in the show at all. I could see possibly using it for Javert's Suicide as it can make a pretty decent looking river, but for the rest of the show it was pretty much just running two hazers almost all the time (just not in the indoors scenes).

Consider this, the original Broadway production of Les Miserables is the show that spawned the Actors Equity Association (AEA) to start to look into possible health concerns with the use of chemical fog and haze. The original production used more chemical fog and haze than any other show to that date. I don't know offhand if/how they used dry ice, but I do know that AEA does not regulate it's use like chemical fog (because it stays low to the ground and you don't breathe it unless you are in it).

On the other hand, since you are in school, you don't have to worry about AEA fog and haze guidelines, so you can run as much fog and haze as you want/can afford to. I have a feeling that the most beneficial effect for your show will be haze, and I would concentrate your funds/effort on either buying or renting a good hazer for your show. Not knowing how big your venue is, it is hard to make a great recommendation, but there are a lot of good machines out there. The Look Solutions, Unique2 is a great machine and very fluid efficient. The Le Maitre Radiance is very similar in characteristics to the Unique2. If you have the big bucks or a bigger space you might also consider the MDG Atmosphere. The Atmosphere requires a CO2 canister, so make sure that you know where you can get it filled if you choose to go this route.

If you NEED the low fog look, dry ice is a good solution. However, and this may just be my opinion, I think that the show calls more for haze and fog than for low fog.

Dry Ice is fun and building a machine can be fun and educational, however it requires a pretty big skill-set, proper tools, proper supervision (for the non-pros), and proper safety precautions. Lets just start with the well known tidbit: electricity and water don't mix well. One of the things that really gets brushed under the carpet in all the threads about making dry ice machines is the safety aspect. We are talking about working with 30-50 gallons of near boiling water, heated by electricity, on a stage with a dimming system. We are talking about then putting a dangerous compound capable of giving you near instantaneous frostbite into said water, causing the release of a dangerous gas. Anyone out there who is building their own dry ice machine, please make sure that you include appropriate fail-safe devices!

[derekleffew]

All good points, Alex, especially the safety concerns. To reiterate:

Originally Posted by derekleffew

...Most of the 55gal drum machines I've seen use a metal milk crate as the ice basket. This creates rust. As many parts as possible should be stainless steel or other non-corrosive material.

A 55 gallon drum 2/3 full is 37 gallons of water which weighs 308 pounds. Know in advance how you're going to deal with that weight, and how to drain the water.

A 110volt heating element can take over 24 hours to bring that 37 gal. of 32°F water back to workable temperature (at least 150°F). No active heating element should ever be left unattended. Hence multiple heating elements, and 220V units of the highest wattage possible, are preferred. The heating element(s) are the least expensive component, and affect the performance the greatest.

The most important components of a machine are its safety features, which should include, but are not limited to: GFCI, thermostat, over-current protection, under/over-level water sensor, etc.

The handling, storage, and use of cryogenic chemicals is dangerous. Heed all warnings, and always use appropriate PPE. When in doubt, consult a qualified professional.

thanx for posting the squirel fan...does that go inside the barrel to suck gas into the tubing or outside in the gas tubing??

The squirrel cage fan goes outside the barrel, usually mounted on the lid, and blows air into the drum, forcing the fog though the ducting an out onto stage.

[Les]

We rented a haze machine for ours and ran it through the entire show.

[gafftaper]

If I were you I would be talking to the local fire officials about disabling the smoke detectors in the theater and going on "fire watch". This is fairly common practice and will probably require you to have an off duty fireman on site. Then get yourself a hazer and go for it.

Picture the scene in your mind: Here's a big gun battle, bang, boom, people die on the barricade, look at that gun fire, there goes Gavroche down, then Eponine... and here comes all the smoke from their guns, rolling down the barricade, crawling across the floor, and into the orchestra pit never more than 18" above the floor.

Depending on where the characters die you might end up with their bodies disappearing in the pond of fog. AND you also have the possibility of them not being able to breathe for real once they are in that fog. Dry Ice fog has the nasty habit of displacing the Oxygen in the air around it... if you lay in it very long you may find yourself passing out or dead.

[BillESC]

You would mount it to the lid of the drum to force air into the machine. The resulting pressure sends the fog out the tubes.

Edit: Oops, didn't see the second page and the same answer already given.

[Van]

went overboard. It's a quick an dirty SKP but it might answer most questions. Follow Dereks caveats. The electrical should only be done by a qualified individual. Sealing everything is incredibly important. Remember water weighs approx 8 pounds a gallon. Even a little weighs a lot.



Ok I lied it's a jpg of an SKP. SKP's are being deemed invalid at the momment. I'll ask Dave if we can fix that.

[gafftaper]

Back to the original post. I question the safety of the garbage can. Seems to me metal garbage cans would be flimsy when loaded with the weight of all that water. I've seen some garbage cans where the bottom is only crimped into place not welded so it would leak. Plus you need to metal work and welding again doubt it can take that... get a steel drum. Won't cost much more and it wont crumple under the weight of 40 gallons of nearly boiling water.

[derekleffew]

Originally Posted by godd2

i agree with the 55 gal drum but i am not sure where i would get one so thus trash cans...

Good point, gafftaper. Many years ago in Chicago, I just looked in the yellow pages, went to an industrial part of town, and was able to buy used (but clean) 55-gal. drums for I think, $5 or $10 each. Today, a quick Google search shows one vendor has them new for ~$64.

Edit: This just in. Some possibly (likely) pertinent information from the ESTA Standards Watch newsletter:

Four ESTA Draft Standards in Public Review
Now there are four draft standards posted for public review at http://www.esta.org/tsp/documents/pu...eview_docs.php.
...
The fourth document, the one available for review through June 22, is:
BSR E1.23 - 200x, Entertainment Technology - Design and Execution of Theatrical Fog Effects, which is a revision of the existing ANSI E1.23 - 2006 standard. The document offers advice on the planning and execution of theatrical fog effects using glycol, glycerin, or white mineral oil fogs or mists in theatres, arenas, and other places of entertainment or public assembly. The revision project is (1) to change the list of fog chemicals in the scope to better match those chemicals normally used in theatrical fog effects, and (2) to better define the qualifications of those in charge of designing and executing the effects.

[Van]

I have to agree with the Gaff and Derek, a 55 gal. drum is really the onlyway to go. A galvanized 35 gallon trashcan is usually only rolled together then hot dipped. Your only reall water seal is the zinc hot dip coating, which will deteriorate when exposed to water and the current induced by the heating elements plus the piping etc. I know that right next to the Penske place here in Portland is a 1 acre lot covered in 55 gallon drums all of which have been safely decommisioned and are ready to sell to the public.
Be sure to know that the barrel you get is clean and safe to use. Nothing worse than starting to cut into a drum with a plasma cutter then read the sticker that say " racing fuel", 'couse then there is the other extreme where everytime we made fog it smelled like " Simulated Strawberry filling Concentrate".

[BillESC]

When we were building fog machines we ordered our 55 gallon drums lined with an epoxy phenolic compound that prevented rust. Secondly we had a bung installed at the bottom of the side. A bung allows you to install a threaded valve to which you can attach a hose for draining.

Instead of a plastic milk crate we used a galvanized wash tub (I forget which size, but one of them fits inside exactly and can be bolted in place.) We drilled a series of 1" holes in the bottom of the tub and lined the bottom with screen to prevent small bits of dry ice from falling through.

Our "Fog-It Super" could hold 150 pounds of ice.