Ways to explode a silicone or latex egg sack prop?

Em-,glass

Hi guys! I'm looking to make a hollow "egg sack" prop (about 90cm tall) that I'll sculpt then cast in either silicone or latex - in an ideal world the sack will explode (with goo inside!) but I'm not too sure how to go about it. 

I've been researching and only have some vague ideas of trying to inflate the prop/pop it like a balloon but haven't seen anyone doing something similar. I just wanted to reach out and see if anyone with more experience with these materials had any thoughts about whether this would be possible or an alternate method?  

Thanks so much in advance!

Chris Ellerby

Inflating it naturally may produce unpredictable explosions.  Though you could place sharp tacks hidden at the base or hidden behind it to puncture the egg after it reaches a specific size.

If a sudden explosion is an option, rather than slow inflation and a pop, you could pre-score the egg so it's already cut through, and even tack some of the pieces back together with a bit of super glue.  Then use a fire extinguisher or other pressure source to blast goo, liquid, or even just air, into it to create the explosion.  Filming at a higher frame rate would also be advisable.  You might need a lot of them to get one good take though.

Here are a couple of courses that cover fluids and explosions:

https://www.stanwinstonschool.com/tutorials/makeup-blood-fx-blow-your-brains-out
https://www.stanwinstonschool.com/tutorials/blood-makeup-effects-the-throat-slash

You could also start with the egg pulsing/moving before the explosion.  For that, you could apply some of the techniques in our bladder course:

https://www.stanwinstonschool.com/tutorials/transformation-makeup-effects-bladder-fx-part-1-design-create-test
https://www.stanwinstonschool.com/tutorials/transformation-makeup-effects-bladder-fx-part-2-apply-paint-shoot

/Chris

Em-,glass

Thank you so much for your reply this is really helpful! A sudden explosion is definitely an option so I'll have a look into that method. Would something like a pressure washer have a chance of working as the pressure source do you think?

Chris Ellerby

I would look into products like the "power plunger" used in the first linked course, a fire extinguisher like in the second, or a garden sprayer.

/Chris

Em-,glass

Thank you! 

Em-,glass

Just to come back to this one- I managed to do a test of this one and everything worked really well except the explosion was a bit too much of a single stream/spray for what we wanted - did you have any thoughts as to how we could get it to look a bit more explosive - maybe create some extra piece for the fire extinguisher nozzle?

Thank you so much again!

Chris Ellerby

To get it to appear more like an explosion you may be able to fill the egg with liquid and small chunks, then send a blast of air into it.  The key is that it be one short blast rather than a continuous pressure release.  I would test various PSI levels to see how different pressures look and always stay within the limits of the equipment.  

Did you remove the extinguisher's default nozzle?  For effects, we normally cut that off, since it can restrict fluid flow.  Then you can attach other nozzles or even something like reticulated foam to shape the spray.  Just be careful that nothing can become a projectile, use proper PPE like safety glasses.

The power plunger might give you a better quick burst of air/fluid.

When sending in air you can also prep part of the line with a bit of extra liquid if you want more than can be contained in the object.

/Chris

Em-,glass

Thank you so much! I'll try all this out. We did just use the default nozzle so that will definitely be something to fix. 

Tom Luca

I realize it's a bit late in answering, but I would say use an air cannon on cue for impact. And if, let's say, you want to achieve a slow-motion look onscreen? Film it fast or "overcrank" it.