Whether a neighbourhood vandal made an appearance or a toddler went wild with a can of spray paint, graffiti on brick can be one of the hardest home or business clean-up projects. The nooks and crannies in the porous surface of brick mean that a rag or sponge just won't work. The situation isn't hopeless, though. There are several ways to remove graffiti from brick in a pinch.
One simple way to get graffiti off of brick is to purchase a graffiti removing cleanser such as Wipe Out Porous Graffiti Remover. Mix the cleanser with water in a spray bottle, and then spray it onto the graffiti. After waiting the specified time recommended on the bottle cleanser, wash the brick wall with a pressure washer. To get the best results, set the pressure washer to 1.5-2 ksi ( thousand pounds per square inch or 1.034 to 1.379 newtons per square centimetre) and use hot water.
Paint thinner is another way to remove graffiti from brick. It takes a little more work than graffiti remove, but it is a much simpler process. Simply dip a nylon brush into the paint thinner and scrub the wall. This process may take a while, but the area will come clean. Due to its labour intensive nature, paint thinner is best used on small areas while graffiti remover works well for larger areas.
A Last Resort
Sometimes, no matter what is used, brick just won't come clean. In this case, there is nothing to do but paint over the graffiti. Be sure to use a primer specifically formulated for porous surfaces before applying paint. This will ensure that the paint will last longer and you will use less paint overall.
What Not to Use
There are some products and techniques that you should never use to remove graffiti from bricks. Always use a nylon or natural fibre brush for scrubbing. A wire brush, though very good at removing graffiti, will also remove the surface layer of the brick or create deep blemishes. Similarly, products containing acids can also etch and mar a brick's surface. Sandblasting is another technique that can damage a brick surface. The sand particles erode the brick's surface and can leave a faded or discoloured area.
Both graffiti cleansers and paint thinners can be highly toxic. Always wear rubber gloves and protective goggles when using these chemicals. Gloves will protect the skin from absorbing the chemicals and the goggles will protect the eyes from splashes. Also, the use of a respirator is recommended, especially if the cleaning is being done within an enclosed area. It will prevent you from breathing in chemical fumes and vapors that may emanate from the products.