Let's talk about methods some people use trying to remove graffiti.
Blasting is a hazardous process. It involves using an abrasive media (Sand, Walnut Shell, Coconut Shell, Baking Soda, Dry ice, etc.) under high pressure to etch the surface. It will remove graffiti but damage the surface as well. Some of the less abrasive blasting options are usually more costly. We don't recommend blasting any surface to remove graffiti, as it will further damage the surface.
Chemical graffiti removers
Chemical graffiti removers can have some pretty hazardous health and safety risks involved. Some give off volatile fumes, while others may cause some cancers. Not a beautiful thing to share with our environment. While some do work to remove graffiti, they may damage the surface leaving it stained or discolored. Some require 24 hour wait periods, while others claim to remove graffiti in 15 minutes. The safer graffiti removers will typically take longer to remove graffiti, and may take several attempts before your surface is graffiti-free.
Pressure washing alone is a very ineffective way of removing graffiti on most surfaces. The amount of pressure that would be needed to remove graffiti can damage the surface by etching or streaking the surface. Pressure washing is typically used in combination with a graffiti removal product to help speed up the process of removal.
A paint over is an option in some cases to save time and money. Paint-overs are for areas where the graffiti is on a painted surface. The paint type used is essential to ensure no deterioration of the surface, as well as allowing no bleeding through of the graffiti. The surface paint must match as close as possible to avoid the paint patch look. Clean the area to be painted free of dirt, dust, grease, or oil. The section with graffiti may have a glossy look; this area might need to be roughed up lightly with sandpaper to prevent paint flash. Always apply paint to a dry, clean surface to avoid peeling.