... after shadow removal, ... ... bleaching of remaining shadow. Photos: Udo Ernst
to be cleaned should always be well moistened. Above all, this is
true for the area where the dirty solution runs down! It ensures
that dissolved color pigments do not penetrate clean areas.
Sinner‘s circle of graffiti removal: Successful graffiti removal
depends on many factors. The most important factors can be shown
using the Sinner’s circle methodology, a methodology applied to
commercial cleaning processes. All factors are interdependent, but
their relationship may be modified. Example: When temperatures
are low, the exposure time must be extended.
Using the three-step method for graffiti removal, all types of
spray paints and varnishes, felt-tips, bitumen, tar and oil as well
and adhesive remnants can be removed from natural
stone, brick, marble, concrete, metal, ceramic, glass, plastic, PVC,
sandstone, slate, terrazzo, wood, tiles, masonry as well as from
smooth, rough and porous surfaces of all types. In every case, a
test should be carried out in a hidden place.
With regard to occupational
safety, the use of special clothing,
gloves and face protection must be ensured. During
removal, food, open fire or smoking are absolutely off
In addition, wastewater from the process should be collected
and properly disposed of. Every German state has discharge
that must be strictly observed. Substances
with dried color residues must also be disposed of according
these regulations. N
Udo Ernst| firstname.lastname@example.org
has specialized in graffiti removal and anti-graffiti measures for over
twelve years. He is a consultant and provides training throughout
Europe as a speaker for Guard KG (Graffiti-Guard).
Solvents can loosen or dissolve some surfaces. When removing
graffiti from sensitive surfaces such as plastics, lacquered surfaces
or Plexiglas, a small hidden area should always be tested first. This
can prevent damage to the surface through the graffiti removal.
Cleaning procedures and processes
Before the actual graffiti removal with the three-step method, some
valuable points must be considered; these belong to the basics of
Outside temperature (Van’t Hoff’s rule): The outside temperature
is especially important for graffiti and shadow removal. For
graffiti removal, temperatures of at least 15 degrees
are recommended. Van’t Hoff’s rule says that a temperature
increase of ten degrees Celsius doubles the reaction speed.
Surface humidity: The surface should always be dry when
the graffiti removal process. This is because 90 percent
of commercial graffiti removers are neutralized upon contact with
water or moisture!
Exposure time: If the exposure time is too long, color can penetrate
deeper into the stone. If the exposure time is too short, however,
too much color pigment remains in the stone, leading to multiple
unnecessary cleaning steps. The dissolved color pigments should
not be exposed to direct sunlight or allowed to dry out.
If a longer exposure time is desired, however, gels or graffiti
removal pastes are recommended. In addition, the area should be
protected by taping with film. In general: Gel is better than liquid
– it remains on the surface longer, which lengthens its exposure
time to the graffiti color.
Protecting the surrounding area: Cover sensitive surfaces around
the area being handled. When cleaning porous surfaces such as
natural stone, concrete or sand-lime brick, the area around the spot
GLOBAL CLEANING | ISSUE 2018 51