| In Practice | Facades
First, the color is removed, ... ... before shadow removal, ...
The graffiti color seeps deep into the many pores of the surface.
After graffiti removal, color shadows may still remain on the
surface. They can usually be removed only with special shadow
remover and the three-step method.
33Protection against graffiti
In the case of porous and uncoated surfaces, semi-permanent
anti-graffiti measures are recommended for reasons of dura-
bility, cost and diffusion capability. If need be, protection with
a permanent anti-graffiti coating is also possible.
Color types and graffiti colors
On the German market, there are over 300 different types of spray
paint and felt-tips. For the purposes of removal, graffiti colors are
categorized into three broad types.
Paint and spray paint: These can usually be recognized by their
wide color application and blurry edges. The color application is
usually thicker in the middle than at the edges.
The removal of spray-painted graffiti is usually unproblematic
on smooth and
polished surfaces. Using the three-step method,
graffiti removal on uncoated and porous surfaces is usually
without residue. Surfaces coated with facade paint
should be cleaned as well as possible from graffiti and then
Felt-tips and ink: Here, the color application is even and the edges
are sharp and uniform. The colors in markers and felt-tips are very
thin and thus penetrate deeply into the surface.
Graffiti applied with markers and felt-tips is especially difficult
to remove from porous and absorbent surfaces and shadows
from the inks may also remain on smooth and polished
But with the three-step method, however, it can
be removed with no residue. In
some cases, several
bleaching processes must be carried out.
Bitumen/Underbody protection spray: Bitumen and underbody
protection spray are among the most stubborn types of graffiti.
They are not commonplace, but still found more and more
Bitumen spray can be recognized based on its color
gradient, i.e. from black in the middle of the surface to brown on
the edges. Furthermore, bitumen spray is very sticky and cannot
be removed with normal graffiti removal agents, or only with great
To remove bitumen/underbody protection spray, the surface
must be dry and a special graffiti remover with a very high
solvent-content used. Many specialized manufacturers offer
specific products for this. The residual shadows often left by
bitumen are usually gone after several bleaching processes.
Graffiti remover (cleaner)
The many types of graffiti color and countless types of surfaces
illustrate the difficulties of graffiti removal. There is not simply
one graffiti remover that solves all problems. For successful graffiti
removal, it is much more important to use the products in the right
order and with the right concentration.
To avoid damage to sensitive surfaces such as plastics, metal or
painted surfaces, the weakest graffiti remover should always be
used first and its exposure time lengthened.
Acids can burn or dissolve most surfaces. In graffiti removal,
only neutral or alkaline graffiti removers are used. This reduces
to the surface through the graffiti removal process.
50 GLOBAL CLEANING | ISSUE 2018