Before beginning to remove any graffiti, you need to first identify what kind of material has been marked by the graffiti. Stone, brick, concrete, glass, aluminum, street signs, and bus stops are just a few of the materials and places where you can find graffiti.
These surfaces can be smooth or textured. Some are painted, while others are not. All of these factors are important to be taken into account before you can decide what process to use to remove the graffiti. Most graffiti is applied using spray paint, but some artists use marks, stickers, or other means in order to mark their material. Each material and graffiti process requires a certain means of removal, which varies depending on the combination of both factors.
Except for paint, graffiti removal materials can not be found in hardware stores or other shops. They must be ordered from specialty suppliers and often are only sold in bulk to cities and professional graffiti-removal services. However, if the graffiti that needs to be removed is paint, you can find these supplies at local retail stores; however they are likely to be specific for small projects. One method of removing graffiti is by painting over it.
This is an easy, usually inexpensive way to remove graffiti. Simply paint over the area marked with graffiti in smooth, even strokes, and you're good to go. This method is also safer than using chemical solvents to remove graffiti. If you do decide to use chemicals, there is a variety to choose from, and it's important to match up the chemical you want with the surface you are using it on. If you do not use the right chemicals, you could ruin the material you are cleaning up. If the job is a small cleanup (off a light pole, for instance), apply the necessary chemicals using a cloth or a rag.
Larger jobs require more dangerous chemicals and often should be handled by a professional. The final method that can be used to remove graffiti is pressure washing. Pressure cleaners spray out water at high pressures and will clean off paint in a good amount of time. You can also use water / solvent mixtures, baking soda, or sand to blast away the graffiti paint. The downside to this technique is that it could wear away the material being cleaned.
Once you have cleaned off the graffiti, all you have to do is apply a protective coating to the surface that was cleaned and you're good to go. While simple graffiti jobs can be cleaned off personally, it would be wise to hire a professional company to clean off larger amounts of graffiti, since they're techniques are safer for the surface being cleaned and they may have access to better materials.