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The scourge of industrial structures, graffiti could be meeting its match
Once mostly an inner-city, lower-income
protest, graffiti has branched out in the 21st
century. But there are good strategies for tackling
the problem – techniques to both remove existing
graffiti and prevent future occurrences that painting
contractors can use to produce an additional
income stream.
QUICK RESPONSE
The most effective weapon against graffiti, the
target of which often remains industrial structures
such as water facilities, bridges and rail cars,
is quick removal. Graffiti is easier to remove
when fresh, and quick removal allows owners to
send a message that graffiti will not be tolerated.
In some cases, detergent and water will do the
job adequately.
However, once cured, graffiti is often difficult
and time-consuming to remove without
damaging the underlying finish or substrate.
Pressure washing can be effective, depending on
the surface and the age of the graffiti. For
tougher cases, sand or other blasting may be
needed, but take care to make sure you don’t
damage the substrate. Stubborn stains may
require paint removers.
BETTER BARRIER
The best way to prevent future graffiti problems
is to apply a “barrier coating.” Barrier coatings
can be divided into two categories: sacrificial
and non-sacrificial.
With both types of barrier coatings, the coating
prevents graffiti from reaching the substrate, making
the graffiti easy to remove. The difference
between the two: In a sacrificial barrier coating, as
the name implies, a portion of the barrier coating
is “sacrificed” during cleanup, which usually
requires no more than a high-pressure hot-water
rinse. When dry, another coat of the sacrificial coating
is reapplied.
The best sacrificial barrier coatings are clear,
water-based, VOC-compliant products that provide
generous coverage rates (upwards of 500
square feet per gallon on painted surfaces).
Sacrificial barrier coatings are generally cost-effective
and safe on most surfaces (though patch testing
is always a good idea).
Non-sacrificial barrier coatings, by contrast, do
not require recoating after new graffiti is washed
off. There are three types: aliphatic urethane compounds,
rubber silicone-based products, and waterborne
polyurethanes.
Aliphatic urethane compounds are two-part
systems that require mixing before application.
Though often used in the past, these products
completely seal the surface, which hinders
breathability and often leaves a recognizably
“sticky” look. They are not recommended for
application on substrates that must “breathe” to
retain their integrity.
Rubber silicone-based non-sacrificial coatings,
on the other hand, are a good choice for
wood and porous masonry surfaces that tend to
trap moisture vapor. The best of these coatings
have a high perm rate that allows moisture to
escape while keeping graffiti and other compounds
away from the substrate. These singlecomponent
products do not need mixing and
provide waterproofing. High performers in this
category provide upwards of 100 square feet per
gallon coverage.
Waterborne polyurethanes are a third and
increasingly popular option. The best versions
comply with volatile organic compound (VOC)
recommendations. They will extend the life of the
surface and are easily maintained.
Waterborne polyurethanes can be used on virtually
any painted or unpainted surface, from brick,
concrete and stucco to wood, plastic and metals
such as copper and brass. You can get them either
in a clear formula or tinted to match any color preference.
Good coverage in this category is about 400
square feet per gallon.
Your Sherwin-Williams Industrial and Marine
representative can provide further information
on how to protect industrial structures from
graffiti. With today’s technology and the right
technique, you can be part of the graffiti solution
in your market.
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