Graffiti Information

Graffiti Removal

 The following are tips for removing graffiti from various types of surfaces.

• The City does not endorse specific brands of products, but rather uses brand names to help the consumer identify these graffiti removal materials and supplies.
• Use caution when using dangerous and toxic chemicals.
• Test your removal methods and materials on a small, unimportant area to be sure they work without causing damage.
• Hire a trained professional for valuable surfaces, historic buildings or unstable materials.

• Remember: Always read product labels and follow all manufacturer instructions and recommendations. Most of the products identified above are flammable - use caution and follow safety directions when using these products. Always use proper safety clothing and equipment (including gloves, safety glasses, etc.). It is recommended that a small "test" area be done prior to a full application of any product.

Removal Methods

There are four methods of removing graffiti. Choosing the most appropriate removal method will in turn save the property owner money and time.

 

Paint over is the most widely used method

When painting over it is important for the property owner to paint the entire surface that has been tagged with a matching paint. It is important that the line of paint be clean and straight and the surrounding area be clean from any paint spills or drips. Following the proper painting techniques is necessary. For questions about proper painting techniques consult a local paint supplier or retailer.

Paint-over Pros		Paint-over Cons
inexpensive		latex (breathable) paint will peel and weather over time
non-toxicity of the product		repeated paint-over prevent the surface from breathing
no electric or diesel tools required		clean-up and preparation time is tedious
location adaptability
Chemical removers are a method to dissolve any unwanted graffiti
There are five types of graffiti removers:
solvents containing chlorinated hydrocarbons	solvents containing monoglycol ethers and glycol acetates
solvents containing diglycol ethers	solvents containing polar solvents
solvents containing miscellaneous solvents
These products are available in a many forms including creams, gels and liquids. Remember: When using any chemical remover safety precautions should be maintained in accordance with the manufactures guidelines, always secure a material safety data sheet (MSDS). For further questions or concerns about chemical removers contact the manufacturer.
Chemical Removers Pros	Chemical Remover Cons
fast and relatively low-labor removal	safety concerns- follow manufactures guidelines and obtain a MSDS
cost effective	require a saturation and dwell time
	may need multiple application and agitation

  

Water-blasting
There are three types of washers that may be used; pressure washers, power washers and jet washers. When deciding which washer to use there are some factors to consider: Pressure rating- this is the intensity of the water stream. General cleaning requires medium to high pressure (500-4000psi). De-scaling or stripping concrete surfaces may require water pressure above 10,000psi. When cleaning delicate masonry water pressure should not exceed 100 psi.
Considerations:
Water flow rate- refers to the supply of water to the sprayhead. The greatest efficiency is likely to be achieved with water flow rates of between 4-8gal/min.
Spray nozzle design- The nozzle design determines the shape of the spray. A fan type nozzle providing a spray fan angle of 15-50 degrees is considered best for graffiti removal and general surface cleaning.
Water temperature-Heated water is useful for graffiti removal from metal surfaces where expansion of the metal helps break the bond.
Chemical or abrasive additives introduced into the stream- When combining chemical removers with water it is important to ensure that the chemical is diluted with water.
When using a pressure washer it is necessary to follow the manufacturer's instructions and guidelines.
Water-blasting Pros	Water-blasting Cons
allows large areas to be cleaned quickly	good drainage required
cost and labor effective	not suitable for most enclosed locations
Sandblasting
This technique will remove graffiti. The result of sandblasting is a more attractive surface than painting over. However, when using sandblasting it is best to sandblast the entire surface, this prevents an outline left by the graffiti. Sandblasting is labor intensive, requiring much preparation and cleanup time. When sandblasting the proper safety precautions should be taken.
Sandblasting Pros		Sandblasting Cons
no chemical agents required		can only be used on non-painted surfaces
no unattractive paint-over		opens pores of surface allow for deterioration
		clean-up is labor intensive

 Graffiti on Different Surfaces

Metal Surfaces

• Try wiping graffiti with any common paint thinner (ex: mineral spirits, lacquer thinner, acetone).
• Try graffiti removal products such as "Goof Off".
• Sometimes wiping the graffiti with light penetrating oil such as "WD-40" or "Three-in-One" will remove it.
• If graffiti remains, try to remove it by rubbing with steel or bronze wool, or light sandpaper.
• If graffiti still remains, try power-washing it with a pressure washer.
• If none of these methods work, paint over the graffiti.

Wood Surfaces:

• If the wood is not weathered and is sealed with paint, stain or sealer, try to remove it by wiping it with mineral spirits.
• If the wood is weathered, do not use this technique, as the mineral spirits will be absorbed by the wood - driving the paint further down into the wood.
• Power washing with low pressure can be used, however, observe carefully to make sure the pressure is not driving the paint deeper into the wood grain. It is not recommended to exceed 700 psi.
• If these methods do not work, sand the wood and re-paint or simply paint over the graffiti.

Plastic Surfaces

• Try wiping graffiti with a light, penetrating oil such as "WD-40" or "Three-in-One."
• Do not use paint thinners as they can soften the plastic and can cause clouding (if clear plastic) or permanent tackiness of the surface.
• Sometimes a light rubbing with ultra-fine steel or bronze wool will remove the paint.
  If these methods do not remove the graffiti, paint over it.

 

Glass Surfaces

• The best method for removing painted graffiti from glass is to use a razor blade to carefully scrape it off. This method is 99% effective. Use the razor blade in a holder and scrape at a 30-degree angle to the glass.
• If the paint does not come completely off after using the razor blade, use ultra-fine bronze wool with water to gently rub the remaining paint off.
• You can use paint thinners on glass, however the razor blade method is much quicker and more environmentally friendly.

 

Masonry Surfaces

• The best option for this type of surface is to power-wash the graffiti with low pressure. It is not recommended to exceed 700 psi. Be careful in selecting the type of tip you use in the pressure wand. Too narrow of a tip (such as 0 degree) will etch the masonry surface leaving a perfect outline of the graffiti removed.
• Sand-blasting is another removal option. As with pressure washing, be careful not to allow the sandblasting tip to remain in one spot too long as it can permanently etch the surface. Keep the tip moving over the painted area and the surrounding area so as to blend in the surface.

If power-washing or sand-blasting does not remove the graffiti, the next best option is to paint over the graffiti.