The most frustrating part of cleaning graffiti happens when you labor over its removal, rinse the area and a shadow or ghost remains.
Here are some suggestions to help you avoid frustration and achieve the clean, un-vandalized, graffiti-free surfaces you desire.
Rough Surfaces
Unsuccessful cleaning of rough surfaces is the biggest problem.
The textures of brick, concrete and stone allow graffiti to sink down into the crevices or pores.
Removers that do not have special penetrating agents or evaporate too quickly won”t get the job done.
Use a soaking-type remover, thickened so it can be applied by a brush, a roller or a low-pressure sprayer, then let the product do the work.
There should be no need for a high-pressure rinse, though low to medium pressure delivers results much faster than a hose.
The pressure helps rinse paint pigments trapped deep in the crevices.
The essential ingredient is dwell time — put the remover on and let it sit.
If you use a remover that rinses even after it dries, you can come back for the rinse at your convenience — even the next day.
Another issue is temperature — not of the air, but the temperature of the surface.
The normal working range for removers is 60 to 100 degrees Fahrenheit.
On very cold surfaces, work in the afternoon and expect to use twice the typical dwell time.
If temperatures are near freezing, use a solvent-based remover.
During the summer months, work in the morning or cool the wall with water.
A water-based remover works better in high-temperature situations.
Plastic Surfaces
Plastics are everywhere: Bathroom partitions, trashcans, banners, playground equipment, etc.
Usually, common spray paint cleans off easily.
If you are having trouble, the paint may be a urethane or an epoxy, such as appliance or engine block spray paint.
Shift up to a stronger remover that can handle those types of paints.
The bigger problem is permanent marker; you can easily clean off the surface, but a stubborn ghost remains.
The essential difference between paints and markers is that markers are made of permanent dyes.
These dyes are microscopic colors dissolved in solvent that can penetrate into the surface.
You may well have cleaned a ceramic bathroom tile, only to see that there was a shadow left in the grout joints — this is the dye that entered into the grout itself.
You must approach it as a stain and use a graffiti remover that is designed for stain lifting.
Just like textured surfaces, there will be a dwell time for the stain remover to work.
Another word of advice: Like any stain, repeated failures to remove it may make the stain permanent.
Because of this possibility, you want to succeed the first time.
Therefore, test your product in a small, inconspicuous spot before attempting the entire mark.
Uncleanable Surfaces
Some surfaces are actually damaged by the graffiti.
The solvents in spray paint can dull some traffic signs.
Signs made with ink are permanently disfigured by markers.
Latex house paint is so porous and fragile that any graffiti soaks into it and, as a result, any sort of cleaning removes the latex along with the graffiti.
The obvious solution for fragile surfaces is an anti-graffiti coating.
These invisible coatings stop potential damage by creating a cleanable membrane that conceals the pristine surface underneath.
Preventing Graffiti
There are three main reasons for using anti-graffiti coatings.
First, very delicate surfaces, those that cannot hold up to graffiti or its removal, should be protected.
Second, if the area receives repeated attacks, a coating allows for faster removal.
Third, in areas where you do not want to use any chemical remover, perhaps in a school or a nature setting, a pressurized water rinse is used alone.
Coatings come in two basic types: Sacrificial and permanent.
The sacrificial barriers are popular, less expensive, safe and fast, but will be partly removed during cleaning; hence, they are sacrificed and must be re-applied.
The permanent barriers are usually very expensive, tough coatings, such as urethanes or nanoparticle paints.
They survive repeated cleanings and can be convenient.
The main drawback is that they are not breathable and have a tendency to delaminate from masonry and other porous surfaces.
If you consider the surface and its temperature, along with the type of graffiti, you increase your chances of being successful in its removal.
Improve your odds even more by addressing the graffiti as soon as possible.
After a few days of hardening and penetrating porous surfaces, the marks are much harder to remove, could cause permanent damage and will undoubtedly cost you more money.
