Whether a playground is in the city or the suburbs, it consists of more than just the brightly colored, sculptured forms. Though these apparatus give passersby their impression of a playground, in actuality, the playground is--and should be--a complex of
Consider a situation with which many grounds managers are familiar: You arrive at your job site in the morning and discover that vandals struck during the previous night, covering your building or structure with graffiti. All grounds managers agree--when this happens, you must remove the graffiti as soon as possible to prevent a reoccurrence. Thus, it's not a question of if or when to remove the graffiti, it's a question of how. Using the correct method can save you a great deal of time and money.
The problem Since the introduction of aerosol spray paint (a favorite tool for graffiti artists), graffiti removal has become extremely difficult. You can remove much of the aerosol spray paint, especially if it is fresh, with mild detergent, muriatic acid (on masonry surfaces) or petrochemicals such as gasoline or mineral spirits. However, if the paint has hardened or if the surface is porous, removal becomes much more difficult. If mild products don't work and powerful cleaning agents or solvents do not remove the paint, then sandblasting, rotary wire brushes or repainting the entire surface becomes necessary--costly solutions for a 5-minute act of vandalism. However, by using the most effective approach in each situation, you at least can make the best of a bad situation.
The solution Seven basic methods to remove graffiti exist. The method you select depends on the surface as well as the equipment and products available to you (see table, opposite page, for treatment methods for various surfaces and graffiti products). The table on page 32 lists some sources of products discussed in this section.
Chemical removers. You can apply a chemical remover by spraying it directly onto the graffiti or applying it to a cloth and rubbing it onto the marks. If the surface is porous, you might have to scrub the surface with a stiff-bristle brush before wiping it dry. Difficult marks may require you to leave the product on the area for a longer time or make a second application. Chemical removers typically contain acetone, butoxyethanol, toluene or 1,1,1-trichloroethane.
Paint strippers. These products contain the active ingredients of methylene chloride and methanol. They penetrate the paint and then, after a short period, you can flush the solution away with a high-pressure water blast. In accordance with manufacturers' recommendations, do not let the product dry on the surface or you may never be able to remove it.
A word of caution regarding chemical removers and paint strippers: The vapors of some of these products are harmful, and the liquid is fatal if swallowed. Therefore, use these products only in well-ventilated areas and wear rain suits, gloves, boots and face shields to avoid chemical contact with the skin, eyes and mucous membranes. Also, first test the chemical on an inconspicuous area to be sure it will not harm the surface. Discard containers and clothing according to applicable regulations.
Non-toxic removers. These products use natural terpene and contain no materials the Environmental Protection Agency (EPA) lists as hazardous. They are non-toxic, biodegradable, non-flammable, water-soluble and have only a mild odor. After a non-toxic remover sets, you can remove it with a cloth or pressurized water. These products emulsify new graffiti in as little as 20 seconds and old paint within 5 minutes. Always work toward the center of the graffiti area to avoid spreading the cleaner into non-graffiti surfaces.
Even though these products are non-toxic, water soluble and biodegradable, you still must use them with care and dispose of soiled cloths properly. Wear goggles and nitrile rubber groves to prevent the chemical from contacting eyes and skin, and avoid prolonged exposure. Non-toxic removers are available in liquid or gel formulas. Besides graffiti, you also can use these products as engine degreasers and gum or glue removers.
Water blasting. This graffiti-removal technique requires a blast of water ranging between 5,000 and 36,000 psi. A blast of about 10,000 psi using 5 to 6 gallons of water per minute removes most graffiti. However, many variables factor into your selection of an appropriate pressure washer for your application. Select a pressure that won't damage the surface you are cleaning. Also consider the temperature of the water and the distance you'll be standing from the marked surface. Both affect the size of unit you'll need for the job. Manufacturers can help you select a model suitable for the material you're removing.
The water from a pressure washer cuts through graffiti, rinses it away and leaves a smooth, clean surface. This approach uses no chemicals, solvents or toxins and does not require safety systems or disposal procedures. The disadvantage of this approach is the cost and size of the equipment. However, if graffiti is a continual problem at your site, you can save a considerable amount of money by investing in a water-blast system instead of purchasing chemical cleaners year after year.
The heart of a water-blasting system is the high-pressure pump, powered electrically or with a gasoline or diesel engine. Select high-quality lances, nozzles, high-pressure hoses and valve systems to ensure your safety and equipment longevity. Wear glasses and protective clothing when working with pressurized water.
Sandblasting. When the EPA banned dry sandblasting several years ago to alleviate dust problems, a new technology emerged: wet sandblasting. This method uses the same silica sand as the dry method, but the sand is mixed with pressurized water.
Two types of wet-sandblasting equipment are available. One kind uses a slurry of water and abrasive, pumped through a wand. The other type initially requires the sand to be absolutely dry, and then combines the water and sand at a mixing head.
Sandblasting machines operate at 3,000 psi with flows of water up to 10 gallons per minute. Round silica-sand particles are best for graffiti removal. The particle size should be between No. 20 and No. 40 screen mesh. Hold the blasting gun straight on or at an angle of less than 30 degrees from perpendicular to the surface.
Sandblasting causes sand and paint to fall to the ground directly under the area you are cleaning. It provides an easy and safe cleanup and, if you're using a water/sand slurry system, you can reuse the sand. The dust-free technology allows you to work without wearing a breathing apparatus, but glasses and protective clothing still are necessary.
Clear coating. This technique requires you to coat graffiti targets in anticipation of future problems with a clear, non-glossy protective coating. This coating prevents paint, marker and other materials from penetrating the surface. Thus, if graffiti occurs, you easily can remove this water-based, non-toxic coating and re-apply a new coating on the unharmed surface.
Painting. Painting over graffiti works when all else fails. Keep in mind that graffiti "artists" do not often attack bright-colored objects. For example, painted picnic tables have far fewer problems than those with natural wood color, and brilliant walls of green, blue or red have fewer problems than brick, concrete or wooden walls. Therefore, if painting is the solution to your graffiti problem, use bright colors to reduce future problems.
Prevention Although this article addresses graffiti removal, prevention actually is the best way to deal with graffiti. If your site has a chronic graffiti problem, use landscaping to hide graffiti targets. Thorny plants and groundcover can control access to targets, and planting ivy or other vines against a building or wall is another good prevention technique.
Installing landscape materials may not seem to be the most inexpensive solution to the problem. However, the one-time cost of planting trees, shrubs, vines and ground covers may be much less expensive than repeatedly removing or painting over graffiti. Plus, you get the added aesthetic benefits from landscape plantings.
Leonard E. Phillips is superintendent of the Park and Tree Division of the Wellesley Public Works Department (Wellesley Hills, Mass.)
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