Controlled Fire Effect

[Gohanto]

For two shots I need a frying pan on the stove erupting with a 12"+ flame and then put out with a fire extinguisher.

My thoughts were putting lighter fluid into a pan, lighting it, and then letting it burn itself out (having the fire extinguisher part take place off camera so that the CO2 doesn't blast any flaming liquid onto another part of the kitchen).

Naturally I'm going to test this with small amount of fluid first and keep track of how much I need plus keeping a fire extinguisher next to me. However, before I started with this I was curious if anyone knows a safer/better way of doing this, or anyway to safely use a fire extinguisher on a liquid burning fire without splashing it elsewhere.

 

[tcindie]

I think doing this indoors is asking for trouble.. and without a licensed pyro-tech also not the best idea.

You could contact your local fire department and explain that you are doing a film, and need this fire effect and were wondering if they have any training sessions coming up that they would be willing to facilitate this and allow you to get your shot.

 

[Anhar_Miah]

go to a trained chief at any restaurant, they should be able to do that for you or at least show you how to.

 

[lifestylefilms]

The problem with lighter fluid is that as soon as it comes out of the lighter, it starts evaporating...
rather quickly I might add

 

[tcindie]

The other problem is that alcohol based propellents tend to burn blue.

 

[kingofcomedy86]

Fire Effects

Fire Effects

Another point you might want to double check before you do this--there are like 5 different types off fire extinguishers that are all made for extinguishing different types of fires. So you may want to check to see if you have the right one if you haven't thought about that. You would need an extinguisher that can put out a Class B fire. So a Dry Chemical extinguisher would work, a Carbon Dioxide extinguisher would work or a Haylon extinguisher. If you already have an extinguisher, just look on the back and make sure it can do what you want.

Secondly, for an effect like this, one would probably use a fire rod or fire pan. Something that can be easily controlled. You can rent that kind of stuff from FX places or you can hire an FX crew to do it for you as well. Whatever you decide to do, be careful, and let us know how it goes!

-Alex

 

[wes]

I did tests on what to use for fire and found that rubbing alcohol works really well as long as you use a towel or something soaked with it. Alcohol based liquids suck alone......but used with something, it works great. The pic here was a paper towel soaked with rubbing alcholol. It burned for a good few minutes before the paper started to singe.

http://bp3.blogger.com/_L_vj3z_9jFQ/R0fOpBAWyBI/AAAAAAAAAoU/EUV6bMeHAAw/s1600-h/fire2.jpg

 

[Neil Rowe]

black screen the fire using a locked shot, same type of frying pan, and using rubbing alchohol in the pan .. just a very little bit will work. (I like to use ether found in car starting fluids because it flashes off very very fast but BE VERY CAREFUL WITH THIS STUFF. IT WILL RESULT IN GIANT FIREBALLS IF YOU USE ANYHITNG MORE THAN A TINY BIT) you can pretty safely black screen in an large indoor open area like a warehouse ect. and push the camera back and zoom in to desired closeness to the flame for the shot. have your live on set shots (that include the burning pan) planned out well for composition and framing so you can plan your black screen composite shots to match, and composite it in in post with screen blending mode after motion tracking the footage. just line up the black screen pan with the live on set pan and stick it there with motion tracking if its not locked shots. you can mask out the black creen pan if its showing up tooo much from screen mode, but i would feather it a little ect. so the realistic glow from the fre is overlayed on top of the real on set pan for your final composite shots. to simulate the extinguishing, you can blow the fire during black sceen work with an air compressor (high velocity air gun tip) to visibly disturb and push the fire horizontally in the direction that the fire extinguisher will be pushing it from. then for your on set shots if you just use a dry chem based fire extinguisher like most off the shelf ones you can buy at a local store then you can spray it on location towards the empty pan like its on fire, and just fade or beatifully mask your flame out in the post composite as its going to be completely swallowed by a plume of dry chem from the extinguisher. the extinguisher will leave that chem dust all over the set so be prepared for cleanup, ..but its realistic. .just get the extinguish shots in one take so you dont have to clean it all up to reshoot it on set, and it should be an easy motion tracked composite from there as long as you dont pass anything over the top of the pan area that would need to be roto'd to place your composited fire behind it.