Slimer and Slime Application

 
 

Ghostbusters II
Ghostbusters II was significantly more slime filled than original, particularly due to the now famous river of slime that is central to the story, as it threatens to engulf the city of New York. Variously known as Psychomagnotheric Slime, Mood Slime and Psycho-Reactive Slime it reacts to emotions, both positive and negative. Primarily pink in the film, It has been portrayed in other colours in the animated series (4).

Stuart Fink, a project manager for GB2 has been quoted that an estimated 100,000 gallons were made, 40,000 of them in the museum scene (5).

As would be expected, a lot of effort was put into both the river of slime and the other ectoplasmic ooze effects in the film, with the team led by the effects supervisor, Chuck Gasper. The basis of the slime was hydroxypropyl-methylcellulose, branded Methocel, and coloured with a food colouring. There were a number of variations between scenes, as Chuck Gasper, speaks about in Cinefex (3);

"The usual formula to create thirty-two gallons of slime, was about eight cups of methocel to four-and-a-half cups of separan. Then we would add about fifty cc's of red food coloring and thirty-two gallons of water. You could actually eat the stuff. It would not have any taste, but you could eat it. The grade of methocel used is also used in pie thickeners and salad dressings."

These quantities therefore equate to the following proportions, by volume:

Methocel= 1.6%
Separan= 0.9%
Food colour= 0.04%

The separan is a "non-ionic polyacrylamide", normally used as a flocculent in water treatment, however it would appear that this grade is no longer in production (certainly under this trade name). It is this that creates the stringiness clearly seen in some of the shots- for more info on this type of material see the main slime page.

As such large quantaties of slime were needed, it was mixed offsite by Blair Adhesives in 1500 gallon batches and tankered to set. Converley it was disposed of by collection by suction truck.

The good news however is that a variant of polyacrylamide is available as 'Sticky Yuck in the US; Sticky Yuck or as 'Slime Baff' or 'Slime Play' in the UK; Slime Play 

I have succeeded in making a very passable version of the slime using 1.5% Natrosol (as I haven't got any methocel, and it gives a clearer goo than guar or xanthan gums) mixed with the slime play polyacrylamide.

The river as seen in the film was shot in miniature and composited with live action shots against a partial set of the subway steps and a matte painting of the rest of the tunnel. The river trough was approx. 1ft wide by 10ft long, on a slight slope fed by a high level dump tank with the slime recirculated back to the tank with a pump.

The specific colourings and visual look of the river took a significant amount of effort and changes to produce; the colour mix has not been revealed but the ooze contained a mica pearliser to give a shimmering effect and had a layer of clear mineral oil on the surface. The river had various air bladders and other methods of affecting the flow with puppetry used to produce further movement and tentacle effects when needed.

 
The River of Slime from Ghostbusters II  

 
Tweeted Slime Image & Slimes Tested

 
Kristen Wiig slimed on set of Ghostbusters
Slime appears to be pumped through a fire nozzle and contolled by an electric or air controlled valve.


Stringiness of the slime

 
 
Slime being mixed- Note the colourant & the powder being mixed in

 
The slime lit from below

 
Tank being filled and then used