Bleeding shrine?

[jessamarie6]

I am working on a Gothic play and in the second act we have a shrine onstage that "begins to bleed." The setup must be quickly assembled as the alter is moved onstage in full view at intermission. The mechanism needs to be operated from below the stage (about an 8' distance from the floor below the stage to the top of the alter where the blood needs to come out). We only need one good spurt of blood, I am assuming that it will be a little sticky and slowly drip down the back wall of the alter for the rest of the scene anyway and I don't want to be too distracting from the action.

Right now I am envisioning a tube under a lip along the top of the shrine with select holes in it, a tube extending off of that, at 90 degrees, running down the back of the shrine to the stage where it can be slipped into a hole. Another hose underneath the floor that can connect easily to the one from above and run down to the ground, and ideally a small tank that I can press on to force the blood through the tubing and out the top (I used an old 2 liter bottle for a similar effect once, but there was far less distance to travel and much lower tech needs.)
My questions- does anyone know of any sort of tubing that is sold with easily fitting joints like I need? Do you think that my pressure system will work over the long distance and against gravity or do I need to look into buying a pump? Does anyone recommend a good, quite, pump they've had success with? There won't be much insulating the audience from any sound the pump might make.

Sorry for the long post, thanks for any advice!

 

[Van]

As long as you keep the tubing size relatively small in diameter the atmospheric pressure you will be fighting, and the mass of the liquid you are attempting to lift shouldn't be too big a problem. When I first read this I thought of using a a reservoir filled with the "blood" then once the tubing was attached you could pressurize the reservoir with an air compressor. If the compressor were pre-filled you wouldn't need to worry about compressor noise. I would attach the female end of a standard air hose connector to the reservoir, this would cut down on leaking prior to attaching the hose. As I said , this was my first idea then I realised you're going to need to prime the system with blood prior to setting it in place, 'cause pushing 8' of blood is going to take a while. So what if you put a reservoir in the base of the shrine and just ran the tube for air pressure to underneath the stage ?
A couple of quick caveats, one be very careful when dealing with anything you are "pressurizing" it does not take very much pressure to cause seriously catastrophic failures.
Second, is on the same lines, it wont tale nearly as much pressure to push that blood as you might think so start out really low, no more than a couple of PSI.

This sounds like a really fun piece. I once did a 18' tall St. ... whats-his-name..... The one who got shot with arrows.... Anyway it was for the Opera Faust, he bled from all his wounds, it was cool. Messy, but cool.

 

[jwl868]

Laboratory supply companies have tubing fittings and tubing. Try Fisher Scientific or Sargent Welsh. I've also seen a good selection of tubing fittings at Lowes.


Joe

 

[jwl868]

I should have noted that polyethylene tubing and vinyl tubing should fit your needs. Either can be purchased at most hardware stores.

And if you really "just need a spurt", (and assuming that stage blood is non-toxic), consider just blowing into the tubing.

Joe

 

[kiwitechgirl]

I'd go about it in a similar way to Van; I worked on a show earlier this year where a character got shot and her brains appeared on the wall behind her. One of the boys built a "blood cannon" to create the effect; essentially it was a piece of metal tubing with a standard air hose connector welded to the end of it, which was then connected to an air reservoir which had a solenoid-controlled valve on it. We'd charge up the reservoir at interval, and then just trigger the solenoid to release the pressure which would fire the blood. If you were to build the reservoir into the altar, all you'd need running to the wings or under-stage would be wires going to the solenoid - you could pressurize the tank at interval before setting the piece. There'd need to be some experimentation with different pressures and amounts of blood, but it shouldn't be too hard to get it right. We were charging the tank up to about 80psi (but it leaked a bit, so by the time we fired it it was down to about 65psi!) and that would fire 125mls of blood and two water-soaked cotton wool balls about 8 feet through the air until they hit the wall with a good smack! The guy who built it did exactly what Van has suggested - tried it at very low pressures to start off with, gradually increasing it until we got the desired effect - he said his garage looked like something out of CSI by the time he'd finished! So yeah, be careful, but pressurized air is probably the way to go.

 

[FatherMurphy]

Depending on how forcefully the blood needs to appear, air pressure might not be needed. One thought would be to use a squeezable reservoir and a solenoid, with the solenoid acting directly on the reservoir (or a servo motor and a cam, if the solenoid is too abrupt). Or, if a slow appearance is fine, perhaps even a cup that a solenoid dumps into a funnel that directs the blood onto the face of the scenery. Viscosity of the blood will make a difference - blood thin enough to pour through a funnel might be too thin to drip properly on the stage side, and thicker blood might be hard to time.

An electrically triggered action will probably be easier to connect during the in-view scene shift than a pneumatic device. You might even rig something with a RC airplane controller, and be completely hidden and wireless.

Since I always like a manual answer, would it be possible for an actor to be behind or beside the altar when the blood appears? If so, he/she could squeeze the blood reservoir by hand.

 

[BrianWolfe]

You don't need a pump. You need a check valve that keeps the fluid in the line. Similar to that in a windshield washer that keeps fluid in the line so that when you hit the button you get instant fluid. Then all you will need is a squeeze bulb to push the fluid through the vent.