Gunge Release Mechanisms

Over the years of running activities using gunge, I have used a number of different release mechanisms. I will update this page with some photos at a later date, so for the time being, this page will just contain descriptions:

The most important thing to remember when putting a release mechanism together is that gunge is more viscous than water, sometimes excessively so, which means that something designed to work with water won’t necessarily work with gunge. In particular the more bends and small constrictions, the worse it will be- therefore something like a toilet cistern really won’t work at all!

Hole in the bucket

The simplest mechanism I have used is to drill a hole in the base of a bucket, approx 25mm diameter, and ensure the edge is well cleaned up (I have a 1” metal punch that works very well). The hole is plugged using a rubber bung (Demijohn bung intended for home wine making), which has a hole of about 5/6mm bored through it. An eyebolt with a couple of large washers is threaded through so that the eye is at the larger end of the bung. A length of cord can then be tied to the bung to allow it to be pulled out remotely.

The times I have used this system, the bucket was screwed through the bottom to a piece of plywood, with the hole in the bas lined up with a large hole through the timber. Silicone (bog & bath sealant), and washers were used to make sure the bucket didn’t leak where the screws passed through. A second piece of ply was attached to the base, vertically next to the bucket. To this is attached a hinged batten of timber, with a hole drilled in each end. One hole is arranged to be vertically above the hole in the bucket, and is connected to the other end of the cord to the bung. The hole in the other end of the batten can have another cord attached to enable the mechanism to be released from a distance (or below).

To use, simply put bung in the hole, fill bucket, and pull cord to release. It will need securing reasonably firmly to ensure it doesn’t move unexpectedly when the cord is pulled.

Down the Plughole 
A variation on this theme is to use a kitchen sink mechanism. I used the plug hole assembly from an old kitchen sink to good effect in the gunge tank shown below. This was simply removed from the sink and fitted to the bottom of a bucket, which was in turn mounted similarly to the previous type.

This particular type of plughole had a cable release which was operated by twisting a knob. This was put behind the tank, so could be released by a hidden stage-hand. It could easily have been extended by using a bicycle brake cable.

Over the top tank
The final mechanism that I’ve used was a very over the top system, which was spectacular, but not without its challenges. The system was used for the finale of a large ‘It’s a knockout’ style competition at a Scout camp, involving approximately 600 kids. The rig was set up on a stage and consisted of a number of main parts.

Tank- This was a wooden construction about 100mm deep, but about 80cm square, with a clear (acrylic front) and mounted on top of a scaffolding tower. The gunge could therefore be seen clearly by the audience, and was dyed with fluorescent colouring to make it stand out in the UV floodlighting we had rigged (All the other main parts were also painted with UV reactive theatrical paint to achieve the desired glowing effect).

The outlet of the tank was a 2” bore pipe, taken through suction hose to a large 2” bore plastic ball valve. This was actuated by a pneumatic cylinder.

Out of the valve, a second pipe led to the ‘gunge head’, which was mounted on a moveable trolley on a track, which was in turn rigged to a 3m high lighting truss (Tri-lite). The head itself consisted of a 2” to 4” solvent weld adaptor with a wooden plug mounted in the centre. The diameter of the plug was chosen so that the area the gunge would flow through was the same as the 2” bore pipe. This made a continuous, hollow 4” stream come out of the head for a greater effect. The head could be moved along the track to over the top of each of four Scout leaders sat on stage by s couple of pulleys and a length of cord.

The release was triggered by a large handle at the end of the game. The handle consisted of a piece of square steel tube (an old table leg) pivoting between two cheek pieces of ply, and actuating a pneumatic cylinder this was connected to the valve assembly and water used as a hydraulic fluid. Again this was all painted brightly.

The vast majority of this rig was made from second-hand or scrap parts, except the truss and lighting which were borrowed.

The rig worked well, once we had thinned the gunge down- it needed to be quite watery to flow at a reasonable rate. The activity was popular, and it had the desired effect.