How to remove graffiti
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
• Chemical removal
• Water-blasting
• Sandblasting
1. 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:
- inexpensive
- non-toxicity of the product
- no electric or diesel tools required
- location adaptability
Paint-over Cons:
- latex (breathable) paint will peel and weather over time
- repeated paint-over prevent the surface from breathing
- clean-up and preparation time is tedious
2. 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. 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:
- fast and labor reductive form of removal
- cost effective
Chemical Remover Cons:
- safety concerns- follow manufactures guidelines and obtain a
MSDS
- require a saturation and dwell time
- may need multiple application and agitation
3. 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 100psi.
- 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:
• allows large areas to be cleaned quickly
• cost
and labor effective
Water-blasting Cons:
• good drainage required
• not suitable for
most enclosed locations
4. 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:
- no chemical agents required
- no unattractive paint-over
Sandblasting Cons:
- can only be used on non-painted surfaces
- opens pores of surface allow for deterioration
- clean-up is labor intensive
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