Trying to recreate actual fire for a music video.

[Asif Limbada]

Hi guys,

I am working on a pre-production for a music video and want to recreate real fire in a indoor environment with little or no smoke, so that it reflects on a pool of water (10mtr by 5mtr tray with an depth of 15 to 25mm) for long period of time.

I was thinking on using wax and rope in a steel tray of 10mt x 1ft, but its not giving me a huge fire look.

Any suggestions guys.

Cheers,
Asif

 

[Asif Limbada]

There is fuel less fire and the other option is flame thrower, that momentarily throws flames when actuated. I think I will go with a flame thrower

 

[Dominik Muench]

butane gas lines, thats what we use in a studio environment where we need fire.

creates virtually no smoke and the flame size is easily controllable with the gas flow. not sure exactly what sort of setup and shape you need....but basically you can go to the home improvement store and get metal plumbers piping and drill tiny holes or slits in them, close one end off with a screw-in end piece and have a pressure valve and a gas hose on the other end so you can attach it to one of those small 9kg BBQ grill gas bottles.

 

[Asif Limbada]

butane gas lines, thats what we use in a studio environment where we need fire.

creates virtually no smoke and the flame size is easily controllable with the gas flow. not sure exactly what sort of setup and shape you need....but basically you can go to the home improvement store and get metal plumbers piping and drill tiny holes or slits in them, close one end off with a screw-in end piece and have a pressure valve and a gas hose on the other end so you can attach it to one of those small 9kg BBQ grill gas bottles.

back of my mind i had this idea, but is it safe?

 

[Dominik Muench]

well as safe as real fire can get....definitely safer I would say than any "physical" elements you light on fire on set....with butane gas there isnt really anything there that can burn...once you turn the valve off its gone....whereas wax and rope are all things that create ash and flying sparks and all sorts of hazards. they are fire sources that need to be maintained permanently in order to keep going.

Plus as far as I know, gas lines are standard practice on most filmsets whenever there is real fire required for bonfires or explosions....relatively low burning point too. Just make sure the place is well ventilated at all times and that the gas isn't left "running" or has the chance to gather somewhere.

 

[Asif Limbada]

well as safe as real fire can get....definitely safer I would say than any "physical" elements you light on fire on set....with butane gas there isnt really anything there...once you turn teh valve off its gone....whereas wax and rope are all things that create ash and flying sparks and all sorts fo hazards.

cool, cos I have never done this, i was a bit skeptical, you have given me confidence.

But is there a possibility of the butane gas bottle to explode etc.

and what about the flame-y effect, possible depending on how big the holes are?

Also i am thinking safety with extra fire extinguisher trolleys etc will be required on set. Any thing else, like sand etc. I mean what safety precautions do you guys take?

 

[Dominik Muench]

the bottle cant explode as long as you have a valve....have a look at any gas operated BBQ gril, its the same setup...a bottle with a one way valve and a hose going into a metal pipe/ burners that create the flame. very easy to make.

flame size depends on the size of the holes and the gas flow....I did a shoot a couple of weeks ago where our production designer had slits in the gas line she used, about 2-3 cm long and about 3 millimetres wide and that created great realistic looking flames.

extra fire extinguishers are a must, a fire blanket would be good and just a bucket of water and a few wet towels to put the hot gas pipes into to cool down.

 

[Asif Limbada]

the bottle cant explode as long as you have a valve....have a look at any gas operated BBQ gril, its the same setup...a bottle with a one way valve and a hose going into a metal pipe/ burners that create the flame. very easy to make.

flame size depends on the size of the holes and the gas flow....I did a shoot a couple of weeks ago where our production designer had slits in the gas line she used, about 2-3 cm long and about 3 millimetres wide and that created great realistic looking flames.

extra fire extinguishers are a must, a fire blanket would be good and just a bucket of water and a few wet towels to put the hot gas pipes into to cool down.

perfect, you are right, its the same setup as a BBQ, lol.

Great idea, will start working on it right now.

Thanks Dominik.

 

[Dominik Muench]

no worries, start with smaller holes and slits at first, you really dont need much to make it going.

have a look at this music video here....its the same basic setup...a metal tube that has gas running through it...wit a speaker attached to it....the speaker creates bass pressure based on the rythm and so the gas line acts as an equilizer....sick idea: http://graetzmedia.com/projects/stan-walker-light-it-up/

 

[Felix K.]

Seriously, I would hire somebody who has experience with live fire FX... there certainly is a regulation that a fireman must be on set when you do this anyway...

 

[Asif Limbada]

Awesomee....hehehe. I likes.

But our flames need to be BIG.

But I get the idea.

off to the workshop.

 

[Robert Hart]

Okay. My two-bob's worth.


1. Spot the hazard.
2. Assess the risks.
3. Make the changes.


If the worst that can happen is you burn yourself, your gear and the location down on top of you it is fine, regrettable but fine as there is basically a Darwin Awards audition going on harmless to others. If you have other humans involved, I would seriously look at getting someone in who knows the pyro trade for live performances or film effects.


For example of why :-


1. Spot the hazard.


What counter-disaster plan do you have? Is there more than one way to escape for starters?



Are any combustables anywhere in the room such as drapes, spiderwebs, flaking ceiling paint, trash, framewood and paper/canvas flats in the sets.

Is the gasbottle secured against overturning. - Liquid propane going out through an outlet brought low by overturning will really spoil your day. If a liquid gas plume goes skyhigh due to a gas bottle pulled over by a careless toe or gaffer's cable in the hose, the atomic rose bursting outwards across the ceiling will set off the curtains and other burney stuff in the room faster than you can think "oh sheise" before you say it and probably the gas bottle will be in centre of the drama where no one can get at it to shut off the gas.

Is the feedline long enough to isolate the bottle and its shutoff valve to well outside of the scene with a human tasked to do nothing else except turn the gas off very quickly if things go to hell. Do not multitask this person.

Holes in a copper pipe letting out gas to burn in a confined space? Fine for outdoors maybe? No mixer for the gas outlets before burning, non-optimum fuel-air mixture may mean carbon monoxide which means sleep peacefully until death with rosy pink cheeks do us part if you are cohabiting with the stuff in a poorly ventilated space.


I'll stop being pedantic now. Why I am I carrying on? A family lost kids here two years back due to a gasbottle and sudden flaring blaze in a camping tent. Furthur north, a mom, son and niece got first degree facial and upper body burns from a gaslamp going over, also in a confined space. Most perfect looking people you could ever wish to meet, now with waxy skin here and there and a bit of portwine coloration, not bad but enough to make somebody ask when met for the first time. You are likely dealing with talent for whom looks are the tool of trade. Get the man in who knows his trade and make sure you or he are insured.

 

[Dominik Muench]

Is the gasbottle secured against overturning.

yep, not to mention what happens to high pressure cylinders such as gas bottles or scuba tanks when the valve snaps off.....ouch....so always have one person holding the bottle and operating the valve regulating the gas flow.

 

[Brian F Kobylarz]

Asif,

Had to create an indoor fire for an industrial shoot just a few weeks ago - enlisted the help of a fire department - will be worth making some calls.

What a number of fire department / safety operations have is a rig that is used to train people on fire extinguishers. I'll describe what we used to give you something to work with:
Starts with a sheet metal tub on wheels that is filled with water.
Under the surface are metal tubes with holes - capped on the end (much like the one someone else described in this thread).
These pipes are connected to a propane tank - just like the ones for your outdoor grill.
They had a remote switch to control the gas flow and to produce a spark (as one would expect with a commercial unit).

So, they turn the gas supply on - gas bubbles to the surface - spark ignites the flames over water.
Size of the flames is controlled by amount of gas supplied.
As soon as you kill the flames on the surface - you are left with a tub of water - not hot pipes.

If you try to build your own, perhaps a cast iron tub of some sort could serve as the water container.
Get the longest hose you can to keep your gas supply control valve away from the actual flames.
Maintain a large perimeter away from flammable materials.
If you can get a hold of some Refrasil, use that to protect items you cannot easily relocate.

Befriend a professional fireman - show them what you are doing.
They may know of someone with one of the commercial units I made use of.
Give them a credit and some volunteers may help you with the setup and standby with extinguishers.
Above all else, consider safety first on this one - fire can be fast, unpredictable and quite nasty.

 

[Christopher Mills]

As someone with professional fire effects experience on my resume....
If you want this to look like a large fire, you should hire an fx pro to coordinate and do this.. if you don't have that in your budget, then you should consider vfx/digital means to create it.. think greenscreen on wall behind the water...
If you want a reflected effect of fire light on the water, and dont feel your vfx people can do it at a price you can afford, then try projecting a clip of fire from a digital projector on the water from above and behind the camera..
Or perhaps lots of lights on flicker generators bouncing off a silver or gold 20x20 on a frame..

Or.. take this outside at night..and hire a fire department for safety..

really, I am not going to discuss ways to actually make a flame bar and rig on a forum, as I then would be liable for any mishaps that may occur...

 

[Mike 'Fireman' Ross]

+1 on hiring someone who knows what they're doing.

+1 on involving your local FD.

You might even get access to their training facilities... this is how we have fun:

Major gas leak training a few years ago. Shot by one of my buddies, I'm the poor bastard in the middle who has the job of crawling through the protecting water fog pattern, under the fire, and turning off the gas!

Mike

 

[Rob Gardner]

+ 2 on getting professional effects people on set. There are too many ways things can go wrong and nothing is more distracting that working on a film set. You must have someone exclusively paying attention to the gas, valves, hoses and flames. Somewhere in your region there are guys who do this, because fire is such a common effect. I'd keep in mind that saying you know how to handle fire and actually knowing how to handle fire are two different things. And safety standards in one country are not necessarily going to be the same as they are in another. Accidents with fire can happen very fast.

 

[Ryan De Franco]

+3 on professional hire. If anything goes wrong with the valve, the line, pretty much anything in a homemade setup, expect disastrous results. What happens if the end of the pipe is not perfectly secured and the pressure turns it into a 2" hot metal bullet flying across the set?

As someone who nearly electrified a steel barge full of 1,000 partygoers... watching the professional fire FX guys roll out their gear, tell the smokers to clear far away, and do what they do exceptionally well.... very calming sight.

Bottom line: do you really want to be walking away from your camera, messing with your homemade flame bar, assuring talent and production it's all OK? Then walking back to your camera and trusting someone with even less experience than you to manage it properly?

 

[Mike 'Fireman' Ross]

Glad to see some people have the right idea.

The earlier posts about drilling holes in pipes, hooking them up to gas bottles etc... bit worrying that. Pro FX people exist and get paid for a *reason*. Would you hire a 1st AC by grabbing someone off the street and saying 'just turn this knob, it's easy, anyone can do it'?! At least they won't blow your set into the middle of next week when they screw up...

Professionalism, people!

Mike

 

[chad vachter]

here in california , over 100 candles burning needs a fire safety officer , city or county and any lit flame needs a fire saftey crew member , as in a guy standing with a fire extinguisher very close to set.

that is for good reason , fire jumps very very quickly , on volcano , propane fire rigs , seemingly safe , were not once nearby fabric caught on fire ,
also a propane mortar with a valve completely engulfed a local 44 spfx guy , as someone walked by the valve and " played with it " while he was putting a tab of fire starting goo in the mortar , used to ignite said mortar. on a movie we did called point of origin . the hardware store set that was built to house controlled burns , also burned down , so be careful , firearms and fire are very cool looking , and give great results , but those are two instances where hiring a specialist is almost mandatory , from a safety perspective

its not just the flame , but nervous/curious or just plain non thinking people are the real danger around fire on set ,

the method Dominic described sounds good, just make sure everyone on set is aware , and exits are clear to everyone .

if you can , go to a fireplace / bbq retailer , they should have propane /natural gas " different orficies " fireplace inserts , that way you don't have to "make "anything they are circular or s shaped tubes that sit flat and send a controllable flame upward , then you can use a portable propane cylinder , and ball valve ,

i have used dominics, method for having flames shoot up from a frying pan , it works great , and the flame is controlled off of set by said ball valve , so it gives a bit of excited face from stunt guy

good luck