fog or the fog machine

[benjamin aguilar]

Hello,

 

I had just recently purchased a fog machine. A very cheap, holloween party, type fog machine. I didn't feel like going to studio-depot to buy a really expensive one. I know there are some good fog juices over at studio-depot, but what I'm wondering is what makes the bigger difference. Is there a certain way that the higher end machines disperse fog that would make even lowest-end fog fluid effective. Or is the fog-fluid what makes an effective effect. I know there are different types of fog fluids, like heavy or lite. What is your experience? Thanks.

 

Benjamin

[Micah Kovacs]

Usually different models of fog machines have their own suggested fog fluids not because they want you to buy from them, but because of the machine's "flashpoint". Each machine has a different temperature that it flashes the fog at, which is the actual process of making the vapor. If the fluid's too heavy and the machine isn't hot enough the fog will come out wet and leave a sticky residue. If the fluid's too light the machine's too hot, the fluid will burn and create toxic byproducts in the air. Both of which are not good at all.

So the only really safe solution is to look at the recommended fluid for your model of fog machine.

 

Higher end fog machines create fog at higher temperatures and have larger pumps so they can produce a greater volume of fog. Cheap fluid in those machines might burn and wouldn't produce a very high yield.

[benjamin aguilar]

Usually different models of fog machines have their own suggested fog fluids not because they want you to buy from them, but because of the machine's "flashpoint". Each machine has a different temperature that it flashes the fog at, which is the actual process of making the vapor. If the fluid's too heavy and the machine isn't hot enough the fog will come out wet and leave a sticky residue. If the fluid's too light the machine's too hot, the fluid will burn and create toxic byproducts in the air. Both of which are not good at all.

So the only really safe solution is to look at the recommended fluid for your model of fog machine.

 

Higher end fog machines create fog at higher temperatures and have larger pumps so they can produce a greater volume of fog. Cheap fluid in those machines might burn and wouldn't produce a very high yield.

 

Thanks. I have bought a cheap 700W fog machine. I was thinking about putting some rosco fog fluid into it. I wonder if that's a bad idea...

[James Steven Beverly]

I bought 6 of the cheap machines, fired 'em up at the same time close together and it created a real nice bank of fog, so don't discount (excuse the pun) cheap machines. :D

[benjamin aguilar]

I bought 6 of the cheap machines, fired 'em up at the same time close together and it created a real nice bank of fog, so don't discount (excuse the pun) cheap machines. :D

 

What kind of fog juice did you use?

[James Steven Beverly]

The stuff you get at Walmart during Holloween, it's ultra cheap works great, I also use 4 or 5 smoke bombs in a coffee can to do a plume of smoke coming out, also very cheap, but you need a pretty open area as the smoke isn't good you, you can also use a bee smoker, but again in an open room. One thing about the cheap machines though, their duty cycle is somewhat short and it takes a minute or two for them to re-heat so they can give you another blast, PLUS they are loud so if you're recording dialog, plan on going with ADR for that sequence or shoot when they're not running and the fog is still hanging in the air.

 

On another note, does anyone know who makes or how to make a smoke machine, not fog, actual thick, black smoke for exterior FX? B)

Edited July 11, 2007 by James Steven Beverly

[Micah Kovacs]

yeah, cheap fog machines are really the way to go. Not only are they inexpensive to buy, but their fluid is cheap and widely available too.

But since they have smaller heating elements they do require that annoying "duty cycle" so they can get back up to flashing temperature.

 

not sure about black smoke though - dark smoke requires a very hot fire that can break things into elemental carbon (the thick black plume which blocks most light)

Any smoke from a machine is vapor which is white and can let light pass through easily - and white fog can be colored I believe but not to a thick opaque black. So I think you'd actually need a real oil/coal fire or something