Removing Graffiti

There are a lot of resources out on the Internet on how to remove graffiti. But to synopsize them, here are the basics.

Graffiti removal depends on surface type. And there are three general types of surface.

- Wood
- Flat Surfaces (Glass, Metal, Plastics)
- Porous Surfaces (Brick, Cement, Concrete, Stucco)

Removal falls into the following basic approaches.

- Repainting
- Chemical solvents
- Pressure washing, sand blasting, sanding

Wood

With wood the best and easiest bet is to paint the surface.

Experts suggest that you should try to stay away from light colours (like white)...as a white wall is pretty much just a fresh canvas. However, going to dark colours (like black and greys) can also present a fresh canvas...just to white markers and paint. The pros and cons vary. With a standard colour like white or black you can always easily repaint. But choosing a colour that doesn't draw too much attention (like a wood simulating brown, or a colour that blend in with the surrounds) is likely a good idea.

If you want to preserve the natural look of wood....you can sand, pressure wash or sand blast the surface to remove graffiti and get down to the bare wood. It's just important to be careful and tentative...as power washers and sand blasters can chew up wood pretty fast. Get a powerful power washer...and put it on a gentle setting...then do some test areas to get a feel for what works.

Solvents can work on wood if you use them early. Most thinners will remove magic markers and acetone will remove spray paint if a day old.

Flat Surfaces

With glass and metal surfaces you can use standard solvents to remove graffiti.

The City of Ottawa currently will provide, free of charge, graffiti removal kits to use on flat surfaces (Tel.: 613-580-2424 ext. 13363). These kits are intended to be used on public surfaces (Telephone booths, Hydro boxes, Bell boxes, Light posts, Mail boxes, Garbage receptacles)...but obviously can also work on private surfaces. If you are going to take advantage of these City resources you'll need to request them and pick them up (at City Hall or at the storage depot by Industrial Avenue). They are intended to clean-up graffitied public street surfaces (so keep that in mind when you request them). If you plan on using them on private surface you should definitely also make a dent in the public graffiti in your area (to keep the area clean and graffiti at bay...your graffiti-clean property won't stay that way long if the rest of your street is heavily graffitied).

Glass and Plexiglass can also be cleaned with a razor blade to scrape away paint. But be careful with the solvent you use, acetone-based solvent will affect plastics. Test spots and carefully reading directions is highly recommended on your first go.

Acetone-based solvents will soften plastics. So best options are to use full-strength paint remover and rinse.

Additionally, metal and plastic surfaces can also be repainted with a colour-matched paint. But choose a paint type that will cover well and adhere to the surface. Scuffing the surface with a little sand paper will ensure that the paint covers better...using a paint that does not adhere well will lead to peeling, flaking and chipping once the surface has had the chance to shink and expand across the year.

Porous Surfaces

Brick, Cement and Concrete can be soaked with solvent and scrubbed gently with a wire brush. After some time to set in...a strong stream of water can be used to rinse the surface. If this doesn't work, a pressure washer or soda-blaster may be needed. If the surface is repeatedly vandalized, it may be wise to look into having the surface coated with a sealer to close pores and make future graffiti removal easier. Repeated pressure washer and blasting of porous surfaces will eventually damage them and compromise their integrity. Conversely, graffiti on brick, cement and concrete can be painted over with a colour-matched paint. Once covered and sealed, graffiti removal can be more solvent based...or surfaces can be repainted to cover any new graffiti.

Graffiti on stucco is most easily repaired with fresh paint. But paint remover and pressure washing can also work. Then use a sealer as a finish coat to protect the surface from follow-up graffiti and make future cleaning easier. If the surface is in a fragile state, the force of pressure washing will remove stucco.

Some additional resources:

http://www.toronto.ca/graffiti/graffiti_tips.htm
http://www.city.saskatoon.sk.ca/org/leisure/facilities/pdfs/graffitiremoval.pdf
http://assets.columbus.gov/graffiti/tips.htm
http://www.multi-sealcorp.com/hints.htm
http://www.paintpro.net/Articles/PP705/PP705_GraffitiRemoval.cfm