Fresnels, fabric and fire...

[JMeG]

Hi

 

After doing a bit of set-up work for my school's show today, I realised there may be a problem with where I want a luminaire positioned...

 

There is a black [curtain] being used under a raised stage section, to mask the crap on the wall behind it, and it runs down the wall and the remaining length along the lower stage surface. I want to position a 650W prelude fresnel on the stage, aimed upwards, but this means the rear of the lantern would be in direct contact with the fabric.

 

Even with extra fire-proofing, do you (the more experienced theatre technicians), think this is a significant fire risk? Considering the heat given out by the luminaire and the fact the fabric is 'proper' stuff (almost like canvas)...

 

Cheers,

 

Jamie

[Tomo]

My gut instinct is to say "Don't do it"

 

Put at least 6" gap between the lantern and the cloth, and you should be okay (assuming it is actually fireproof)

 

(One inch is probably enough, but always do more than required and you'll be fine)

 

Even if the drape is inherently fireproof, you could damage it and/or the luminaire.

And there's no such thing as totally fireproof anyway, it's purely a case of how hot it has to get before it burns.

 

(Aluminium has a flashpoint of about 700deg C, and is almost inextinguishable!)

[SparkySteve]

Even if the material is fireproofed it won't stop it from warping or even melting... You could end up with a nasty disfigured cloth. I remeber an incident back in the old days (School *shudder*!) when someone decided to see how fireproof the fireproof curtains in the science lab were.... they shrivelled and melted antil they were disfigured and half their origional size

[Brian]

Fire proof fabric often isn't 'Fire Proof' but is more correctly 'Flame Retardant'; which means you can set alight to it but the flames will go out and not spread. With man-made flame retardant fabric it will melt when it gets hot but not catch alight, remember that hot dripping polyester can set alight to things it falls upon.

[Big_ gray]

It will proberly give you a very nice smoke effect, for best results try a 2k lamp ;) (only joking don't do it!!)

[JohnMac]

;) Don't do it...

I was playing keyboards in a pit of a small theatre, Singer went off the wrong side and flicked a black leg if front of a PAR Can on a low floor stand doing some cross lighting.

 

Next act came on and started singing, PAR can came on and started singeing the fire proofed blacks. Within minutes a charred hole appeared, accompanied with lots of foul smelling smoke.

 

Fortunantly the sound engineer from the rear of the stalls saw what was happening and rushed down and put it out with the remains of his fizzy drink can.

 

Lanterns legs and cloths do not mix. Its the closest I been to a stage fire.....

[SparkySteve]

put it out with the remains of his fizzy drink can.

That's probably even worse! :D :D :D elctricity and liquids don't mix, an I'm sure if the leg was close enought to burn, the lamp would have got covered in pop!

[robloxley]

Fire proof fabric often isn't 'Fire Proof' but is more correctly 'Flame Retardant'; which means you can set alight to it but the flames will go out and not spread.

Likewise you can set fire to class 1 ply quite nicely if you try...

[Jivemaster]

I suggest the judge would say Arson and you'd plead Guilty.

 

Often a luminaire will have a "distance to nearest flammable surface" rating and typ 500mm. Try including a piece of plaster board painted with heat resistant paint -- matt black engine paint (poss Halfords) Or redesign to include adequate clearance and free air flow.