While paint is the most common graffiti ingredient of choice for "tagging," these vandals also etch and scratch glass with their unwanted graffiti. Most is removable, but you need to know what it takes to get it out, off and away from the substrate.
Michael Griggs, CR, Disaster Restoration, Inc., Denver, Colo., is the former president of the Association of Specialists in Cleaning and Restoration's (ASCR, www.ascr.org) National Institute of Disaster Restoration. Probably the biggest secrete to successful graffiti remediation is, "The sooner it can be removed, the better."
"We urge clients to call us as soon as possible before the paints sets and cures," Griggs said. "The object of the taggers is to cover as much area as possible as fast as possible. For that, spray cans work very well, and per incident taggers can cover a five by five square foot area or larger depending on the time allotted to them. Undetected or uncleaned, taggers can-and will-cover entire walls.
The substrate is the key to cleaning
"Determine what the substrate is and decide on the least aggressive method first that will not alter the surface and will clean or extract the paint," Griggs, said. He suggested obtaining a piece of similar substrate to work on, testing a variety of methods, cleaners and techniques. Test several solutions to find the best one before attempting cleaning on the customer's surface, and then determine the least aggressive method, becoming more aggressive until the solution is found.
Some materials are easier to remove than others and some substrates allow it to be removed more easily. Determine how long it has been on the substrate and under what conditions, i.e. direct sun, rain, snow, indirect light, in shadows. Has a staff member attempted to clean it off before, how, and what were the results?
"By studying the situation and determining the method to use, you can avoid driving the paint further into the substrate," Griggs said. "However, be aware that you cannot be successful 100 percent of the time unless you become very aggressive."
He suggested starting with a mild soap, water and soft bristle brush depending on the surface. "With a wood substrate, be aware of the topcoat. Rarely is the wood left natural without a topcoat and the topcoat is key to how to cleaning will go. On wood, be aware that it may be more cost effective to replace the wood if it is porous, older, or unique. Clean a similar product or use solutions in an inconspicuous place when possible before going after a place that shows."
He also suggested brushing wood off first followed by light sanding, depending on the time the paint has been on the wood. If appearance is important, consider replacement.
Brick, masonry and other hard surfaces, such as concrete, require the brush and water method to start with and chemicals depending on the porosity of the brick. Do not drive the material further into the brick. Power washing is effective and chemicals may be added to the power washing. Grit blasting (soda or dry ice) is more aggressive moving all the way to sand blasting, which will change the substrate. Concrete and brick can take more aggressive cleaning by their nature and durability.
Power washing with water is hit or miss and takes a lot of time. Griggs prefers soda blasting or Cryo blasting (dry ice) because they tend to be more aggressive without damaging the substrate and are more adjustable and flexible to work with.
While paint can be easily removed in certain situations, the longer it remains in contact with the substrate, relief, facets, highly absorbing materials and soft porous materials, the more difficult it will be to remove.
Facility manager should consider power washers, grit and media blasting materials, according to Griggs. "Most manufacturers will allow testing of their equipment and may assist or provide minimal training with the equipment to determine its capabilities," he said. "Before buying, make sure it will do what you want it to do."
Griggs also recommended Certified Restorer training from the ASCR for building maintenance professionals or their staff. The training will provide an abundance of techniques and technology and a clearer understanding of how to match the specific kind of graffiti to the material, including using poultices that are compacted or pressed and can be put on very porous materials to have the effect of absorbing and drawing out the applied materials from the substrate. The more training and the sharper the skills, the less costly the removal will be.