Friday, 15 June 2012

Elephant No. 257: Silly String

I've been wanting to do a Silly String elephant for a while, but couldn't find the stuff in local stores. I don't think I've played with Silly String in at least 20 years, so I had no idea how well this would work, but I figured it would at least be fun to try.

Silly String—also known as play string, party string or aerosol string—is a plastic material expelled from an aerosol can as a thin stream of foam. The solvent that keeps the string flexible dries in mid-air, creating a continuous strand.

Silly String was invented by Leonard Fish and Robert Cox during their development of an aerosol spray-on cast for broken limbs. In 1972, they received a U.S. patent for a white "foamable resinous composition" they called Squibbly. The material was later licensed to the company Wham-O (of Frisbee fame), which renamed it Silly String and sold it in a range of colours.

The primary material in Silly String is a polymer called polyisobutyl-methacrylate, dissolved in a solvent that causes the polymer to foam. The solvent evaporates almost immediately once out of the can. The pressure inside the canister can propel the string up to 6 metres (20 feet), and each canister contains an average 120 metres (400 feet) of string—although one test measured over 490 metres (1,600 feet) of string.

Although Silly String and its knockoffs are widely used during parties, festivals and holidays such as Hallowe'en, the material isn't entirely benign. The evaporating fluorocarbon propellant can be extremely cold, with the theoretical potential to cause frostbite. The polymer itself can be mildly irritating to sensitive skin. The solvent is also flammable, although the string itself is said to be flame-resistant. As seen in the video below, Silly String should never be used near an open flame (such as birthday candles) or even a hot lightbulb.

When it was first manufactured, Silly String contained a fluorocarbon that was harmful to the atmosphere. In recent years, however, the formulation has been changed to avoid damaging the ozone. Silly String can also eat into vinyl surfaces such as inflatable toys, upholstery, vinyl wallpaper, and even the vinyl tops on older cars.

Interestingly, for a number of years the U.S. and British military have used Silly String to detect the tripwires of IEDs. The material is sprayed over a suspicious area and, if the Silly String falls to the ground, it is assumed that there are no tripwires. The string would of course catch on tripwires—fortunately, while not being heavy enough to activate the explosive device.
In many regions, Silly String is seen as a complete nuisance. The cities of Ridgewood, New Jersey and Middleborough, Massachusetts, for example, have an outright ban on its use. Similarly, the town of Huntingdon on Long Island has banned the sale of Silly String within 460 metres (1,500 feet) of a parade route. And in Hollywood, Silly String is banned for a 36-hour period each year from 12:00 a.m. on Hallowe'en through noon on November 1.

Today, Silly String has many imitators, and is thought to be the best-selling novelty item in the world. Because most people buy multiple cans of Silly String and use it up quickly, sales have remained high for nearly 40 years.

For today's elephant, I bought two cans of Silly String from a discount store, for about three dollars each. I've used this only once, at least 20 years ago, so I couldn't really remember how it behaves. I vaguely remembered a plastic substance that was almost impossible to remove once it hardened on a surface; but maybe it's changed since then.

I bought a can of green and a can of purple because I thought they might look interesting together, but I wasn't sure how much space I'd need to spray this in. If it tends to propel 6 metres or more, I need to be outside. I thought briefly about staying inside, then changed my mind and went out onto the front porch.

I bought a couple of sheets of black bristol board measuring 60 x 90 cm (24 x 36 inches), and laid one on the porch.

I started by spraying some of stuff in the purple can. To call this purple is laughable. It's barely even blue. And there was something wrong with the propellant. No matter how much I shook it, this canister never really worked. It gave me more splatter than string, and towards the end it actually spewed liquid.

Next I added some of the green. This worked much better, but was still a disappointing colour. I thought I was buying bright colours like the caps, not these pale versions. Oh well.

I was beginning to get the hang of handling the string, and began to like it. You can even reposition the string on the paper if you want, although I didn't really do this. That being said, it's really not a manageable medium. But that's okay if you don't mind something highly abstract. And I do mean highly.

I finished up this elephant head by adding a bit more green.

Since I had another sheet of black bristol board, I decided to use up the rest of the green on a whole elephant. The "purple" had long given up the ghost.

By playing with the angle of the canister and the pressure you apply to the button, you can get slightly different effects. The light splatters come from light pressure, and/or holding the canister upside-down, and/or using the absolute dregs of the canister. The long looped strings—they loop on their own—come from spewing string in an arc from fairly high up. The relatively straight strings come from using the heaviest pressure on the button and a medium distance. At least, those were my results. You might get something completely different, particularly if there's a breeze.

This was a quick and relatively easy activity, once I got the hang of "drawing" with Silly String. The final pieces are not the least bit permanent, because of how easily the string flakes off the bristol board. But I have to say that it was fun to try making something representational with a medium that basically has a mind of its own.

Elephant Lore of the Day
How's this for high-tech? Elephants in some parts of Kenya now send text messages to let wildlife rangers know that they are heading for the crops in neighbouring villages.

No, this doesn't mean that elephants have evolved opposable thumbs, but they do wear radio collars that automatically send a text message if an elephant strays too close to a farm.

The technique was developed by Save the Elephants after the Kenya Wildlife Service was reluctantly forced to shoot five recidivist crop-raiding elephants from the Ol Pejeta conservancy. The system was first tested on a large bull elephant named Kimani, who was a regular raider. A mobile phone SIM card was inserted into the radio collar Kimani already wore. The team then set up a virtual "geofence" with GPS coordinates matching the conservatory's borders. When Kimani crossed this line—usually at night—the chip in his collar sent a text message to rangers.

Text message sent by elephant, Kenya, 2008.
Photo: ©AP

Rangers would then mobilize, tracking Kimani to his location. They would then use flashlights and noise to warn him away and frighten him back into the 36,400-hectare (90,000-acre) conservancy. Kimani was intercepted 15 times during almost nightly raids, before finally learning to avoid farmers' crops.

Bernard Lesowapir from Save the Elephants
uses a radio transmitter to locate an elephant,
after he is sent a text, Kenya, 2008.
Photo: ©AP

The project is expensive, requiring five full-time staff and a dedicated vehicle. It also has logistical problems: batteries wear out and must be replaced, and local communities have come to think that a collared elephant means that the people who collared it should be held responsible for any damage the elephant causes.

Despite these issues, the project has been a success, and has already been implemented in other parts of Kenya with similarly troublesome elephants. Interestingly, because elephants learn quickly from one another, controlling the crop-raiding behaviour of one elephant will make a whole group change its habits. This has meant a drop in the average 1,300 complaints received by the Kenya Wildlife Service each year, and less need for nightly watches by villagers banging pots and pans, setting off firecrackers—and using guns.

African bull elephant Kimani with radio collar, Kenya, 2008.
Photo: ©AP

To Support Elephant Welfare
Elephant sanctuaries (this Wikipedia list allows you to click through to information
on a number of sanctuaries around the world)
Wildlife Trust of India

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