Safe Short circuit for B- Movie FX

Hello again!!

A friend of mine came with a basic yet interesting project. He makes ultra-low-budget B movies, and he wants to impress his university collegaes with cheap FX.

He is planning to film a secuence where electrical equipment (i.e. mad scientist base) is destroyed by the main character. So, he got a bunch of old computer carcasses and similar junk, and planned to blow em' making a short circuit inside

I stopped him on time! What could be a better way to generate short-circuit type sparks?

1) No pyrotechnics, powder or explosives are available *legally* here

2) A small piece of copper between two electrodes blows nicely at 120VAC, and is our prefered method by now. Do you know any decent method instead?

3) I guess repeated intentional tripping of the circuit breakers may reduce its life. Am I right?

3) To prevent a catastrophic failure (breaker stays ON), I suggested to buy this array


Electrodes ----- 15 amp breaker ------- 40 amp breaker ----- 115VAC

I think the 15 amp will trip first, and if it fails, the 40 will take its place. Is that correct?

4) I guess a metallic sponge would perform better, due higher resistance and multiple paths to blow during the short (result= more beautiful hot metal flying). The problem: circuit breaker act too soon, and the short is not powered during enough time to burn all the material. Any suggestion?

Thank you so much! He's going to put us on the credits, if the work suceed.

Menticol said:

I stopped him on time! What could be a better way to generate short-circuit type sparks?

.

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A welding machine is a controled short circuit with sparks if you keep the arc going.

Robert-Jan

rjvh said:

A welding machine is a controled short circuit with sparks if you keep the arc going.

Robert-Jan

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You're right Robert, but the intense UV light would blind both camera and actors, so that option can not be used.

Have you had a play with Steel Wool yet - that can make some impressive sparks/flames/smoke etc ?

Also look at Sodium Chlorate (weedkiller), if you can get the stuff without all the inhibitors it makes a pretty fast burning flame.

The problem: circuit breaker act too soon, and the short is not powered during enough time to burn all the material. Any suggestion?

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Ugh - I hate to suggest using a car battery, but you need a lot of current and not a huge voltage. Put a wooden box over the car battery in case it accidentally vents.

Thank you so much Picbits and Duffy! I'm gonna tell em about your suggestions. However, I guess 115VAC and steel wool will be chosen, because the battery is too expensive for our budget (Imagine a pocket with a coin, a ball of dirt and a spider web).

If the budget increases and the battery is affordable, I'll sugest the team to bury it (not very deep) and leave a small vent, to stop the sharpnel in case of explosion.

Probably won't explode, they are designed to handle a near short-circuit.

When you get this thing filmed, please post a link to the money shot!