Porous and unprotected surfaces, such as many kinds of natural stones as well as sandstone, travertine or limestone, and also concrete.
Graffiti can be removed from basically all types of surfaces. It is important to choose the appropriate graffiti remover as well as the gentlest process for the substrate. Whether graffiti can be removed easily or not depends on the surface and the type of paint used (permanent marker, spray paint, undercoating, and etc).
Graffiti removal from unprotected surfaces is particularly difficult. The success depends on the substrate, the type of graffiti paint, the cleaning product and of course the cleaning technique.
The removal of graffiti from unprotected surfaces is achieved through the use of a special graffiti remover selected for the specific surface. The graffiti is then rinsed off the cleaned surface, usually with high pressure hot water.
Any remaining color shadows are then treated with a special shadow remover or a bleaching agent.
All types of spray paints and varnishes, feltpens, asphalt, tar and oil can be removed this way from natural stone, brick, marble, concrete, metal, fired clay, glass, plastic, PVC, sandstone, slate, terrazzo, wood, tiles, plaster as well as all as other types of smooth, raw and porous surfaces.
Basic factors - most common sources of error
The most important factors for a successful graffiti removal are listed below. Most cases of error during an unsuccessfull graffiti removal can be due to a failure of one of the following factors.
- Outside temperature, ideally above 15°C!!
- A hot water high pressure device should be used to remove the dissolved paint from the surface!!
- Pay attention to exposure times!! If necessary, the graffiti remover, especially with older graffiti, should be covered and left overnight.
- For better results you should work the graffiti remover into the surface with a brush!!
- Generally use the 3-step method (color removal, shadow removal and bleaching) for graffiti removal applications.
PRODUCT: e.g. Remover BLUE or Plastic G
The right graffiti remover for step 1 is selected based on the sensitivity of the surface and / or the applied graffiti color (spray, ink or bitumen).
- Contact time at 15° degrees - for at least 20 minutes.
- Apply with a roller or brush.
- Work in with a brush.
- Rinse with high pressure hot water.
CAUTION!! Do not use dirt cutters or point jet nozzles for high pressure cleaning! Not too close to the surface with the high pressure nozzle! The graffiti paint should be only washed out of the surface!
PRODUCT: Shadow G
- The surface should be dry or not
be very wet!
- Apply with a roller or brush!
- Work in with a brush!
- Contact time at 15° degrees - at least 15-20 minutes.
- Rinse with high pressure hot water as soon as the color / shadow is dissolved from the substrate.
PRODUCT: NaClO 13 % or BLEACH G
- The surface must be dry!
- Apply a filling with a roller or brush!
- The pigment bleach can remain on the
substrate until it is completely dry again.
- Posibility: cover and leave product to work for a long time.
- Salt crystals after pigment bleaching can be rinsed off with water.
Processing recommendations for pigment bleaching can be found in the product information.
CAUTION!! For all work steps, please wear adequate protective equipment, such as chemical protective gloves and eye / face protection.
Graffiti should always be removed immediately! When there is already graffiti on a house wall it tends to invite further defacements. Once illegal graffiti is immediately erased, the appeal to sprayers is lost and they quickly lose interest in the graffiti-free surface. Copycats will no longer be as encouraged because the inhibition to deface a clean wall is less than with an already vandalized one.
For the following three reasons vandalized areas should not be painted over without first removing the graffiti: lack of breathabilty of the facade, „bleed-through“ of the painted-over graffiti and poor carrying capacity (spray paint) due to the existing graffiti. „Negative shadows“ of the smearings might still be visible after cleaning. However 98% of the color shadows can usually be eliminated.
The use of special solvents on painted or varnished surfaces triggers the removal not only of the graffiti but also of the underlying paint or varnish. It might therefore be necessary to repaint / revarnish the affected area.
The graffiti removal process depends on weather conditions and should not be done when it rains or by temperatures below 5° (night frost).
Once the graffiti has been removed, the cleaned surfaces will appear brighter than the uncleaned ones since cleaning products and the pressure washing, where required, also remove older environmental pollution.
Make sure to close windows and blinds that are near the defaced surface and to keep parking areas empty to avoid damages.
The choice of the appropriate graffiti remover depends on the type of paint and on the surface.
Click here for help on selecting the appropriate graffiti remover
