It is best to clean graffiti as soon as possible so the paint doesn’t have time to absorb
into the surface. It is worth it to keep paint or removal products on hand so that you can quickly paint over or remove the graffiti should it become necessary.
PAINTING OVER GRAFFITI
If a large portion of a property has been vandalized, it may be cheaper to simply repaint. A $10 gallon of paint covers the average
100 sq. ft. garage door
for an average cost of .10 a sq. ft. It will also give
you the opportunity to
change the paint to glossy enamel, which will resist future graffiti attacks better than a flat finish. For added protection, an extra gallon of the same type
of paint will help ensure a quick and painless
perfect match if graffiti returns.
Before painting, try to clean the surface of any dirt or grease. Certain marker pens and indelible markers have the ability to absorb paint pigments. That’s what makes them permanent so use a special paint called a
stain blocker. Also, if the base color is light and the
graffiti a dark color, use a
stain blocker first. This special type of paint prevents the darker paint from seeping through the fresh paint.
Oil or Latex Paint? Sealers? Foam Brushes?
Oil base paint is tougher than latex. Latex is cheaper and easier to clean up. Though not recommended, oil base, can be applied at below freezing temperatures if needed. Oil base takes longer to dry, but can be used if light rain threatens. Once the new paint is on, you might consider using a “sealer” or “protectorate.” These types of products seal the small surface pores and prevent graffiti’s ability to adhere. Once sealed, the new graffiti is easier to remove with less work. Some protectorate systems sacrifice a small amount of the sealer and need to be reapplied after the graffiti is removed.
As a good insurance policy, buy some foam- type brushes. If graffiti reappears, use the foam brushes and the new paint will blend into the old with perfect results. Then just toss the brushes away since they are inexpensive.
IDENTIFY TYPE OF SURFACE
Brick, Cement or
Use extra strength paint remover, graffiti remover. Apply with a wire brush to work into
holes and pores of stone. Allow time to activate 10-
15 minutes - and rinse with a forceful stream of
water from a hose. Use of a pressure
washer or soda-blaster may be needed.
Note: Sand, soda and water blasting will wear down brick and concrete so consider sealing the surface.
If the surface is uniformly flat, a light grit (60) sand paper can remove paint, but will also scratch the surface. Consider using a
sealer after removal to close pores and make future removal easier.
Painted Brick or
Using eggshell and oil based paints will create a smoother surface and will be easier to clear graffiti from them in the future
as opposed to masonry paint.
Some have found success with zest of orange fluid on brick. You will need lots of water to wash and rinse the surface. After washing, rubbing dirt into the brick with another brick will help restore the finish.
Due to the multi-faceted surface of stucco, it is impossible to sand off. Use paint remover and follow up with a high- pressure water hose or better yet a pressure washer. Use stucco paint and go over the graffiti carefully. Consider using a sealer as a finish coat.
Aluminum or vinyl siding:
Aluminum siding is
usually coated or painted. Vinyl siding is made of plastic, which can be marred by lacquer
thinner-type cleaners. Solvents may work too aggressively and remove the coating as well. Experiment in a small inconspicuous area first
and then tackle the more visible areas. Use paint remover sparingly and carefully. Use a clean
rag and keep turning to a clean part of the rag before each wipe. The longer the solvent stays on the surface, the
deeper it penetrates. In most cases, you will
probably have to repaint.
For vinyl siding it is better to paint using “grab-it” as a primer, which will help the paint adhere to the vinyl.
Try working up the solvent list if the marks are new. Most thinners will remove magic markers and acetone will remove day old spray paint. You must use a clean rag and keep using a fresh part on each wipe. On latex or oil- based paint, use a stain- killing primer for exterior use. After the primer or stain blocker coat has dried, you can proceed
with regular paints, oil or latex. Most oil base paints are more durable to solvents and hence could make future clean up easier. Consider a sealer coat after final finish. Avoid using flat paints as they readily absorb pigments from markers and spray paint.
Creosote and wood dye are useful if graffiti is embedded into the grain of the wood.
Depending on the type of graffiti, work your way up the thinner list. Beware that acetone-based solvents will soften plastics. Use paint remover full-strength and rinse carefully. Use the paint thinner in an inconspicuous place first to assure it will not mar the surface.
Glass or Plexiglas: On regular glass any razor blade can scrape away cured paint. For other marks any solvent can be used. Use the clean rag technique and hold the rag over the graffiti for a moment to let the solvent work. On
Plexiglas be careful of the lacquer thinner-type solvents as they can attack the surface
causing it to fog and smear. Make sure your product is compatible with the type of surface you are cleaning. Rinse thoroughly.
On any unpainted metal
(iron or stainless steel) surface, any solvent can be used. Some polished aluminum surfaces will cloud or oxidize with aggressive cleaners like lacquer thinner. Use the clean rag technique. If you are unsuccessful, try paint remover.
Wipe quickly with lacquer thinner. Rinse with water. Be cautious as solvents can mar these surfaces.
Surfaces scratched deeply or scored with
sharp objects can only be
filled with fillers or the material will have to be replaced. Some new types of glass have replaceable covers or film layers that are cheaper to replace than the etched glass. Automotive body fillers can fill deep
gouges, then be repainted. The only
other recourse may be to replace the glass. If that
is not possible, you might discourage future etching
attacks by using fogged glass. You might deny
the vandal visibility by etching over the vandal’s
mark, thus turning a “P”
into a “B” and so on. It’s a psychological solution, demonstrating that this area will not tolerate the vandal’s message.
HOW TO PREVENT MORE GRAFFITI
If you have to paint over graffiti, it’s very frustrating to have it vandalized again. Here are two ways to paint out graffiti that will
discourage further vandalism:
THE BEST WAY-
Paint the Entire Wall:
Repaint the entire wall,
or paint up to 7 feet high (making a straight line across the top) with a color that matches the wall. This leaves no trace of graffiti and does not draw the attention of the vandals. This method is
10 times more effective than patching.
THE NEXT BEST WAY- Paint in Patches:
When it is not possible to
paint the entire wall, use a closely matched color blocked over the graffiti in neat, square shapes. The closer the color
match, the more effective it is in preventing further
BASIC CHEMISTRY OF SOLVENTS
A solvent is a substance, usually liquid, that will dissolve another substance. Choosing the right solvent will make a job easier; using the wrong one can damage tools or the work project. To avoid making costly mistakes, one should be familiar with the most useful solvents and where, when and how to
use them. The longer the graffiti has to dry, the stronger the solvent and more difficult the
cleaning process will be.
Time may be your best
tool….don’t delay remove it TODAY! Obviously, most chemical solvents are flammable and release toxic fumes. Be sure to read the manufacturers' instructions before using them and observe all safety precautions. Buy them in quantities-only
as much as you need-and
store them in metal containers away from children, pets and flames.
THINNER LIST Turpentine:
Is produced by distilling the oleoresins from the pine trees. It is also known as spirits of turpentine or turps. The best grade of turpentine is called pure hum spirits of turpentine. Turpentine has more solvency than mineral spirits. Even though turpentine is less toxic than petroleum based solvents, it can cause an allergic reaction in some individuals.
Mineral Spirits: Also called “white spirits”, is a petroleum distillate specifically manufactured as a
substitute for turpentine. Most painters prefer it as a paint thinner because it costs less is not so sticky and has a less offensive odor than turpentine.
Turpentine and mineral spirits are good first-try
cleaners, although turpentine can remove paint that has hardened slightly. Mineral spirits will dissolve only fresh paint.
Is a petroleum solvent similar to mineral spirits but with a greater volatility. It is used chiefly as paint thinner or as a cleaning agent. Naphtha is a more powerful solvent than mineral spirits, so less is needed to dissolve the same amount of paint. Naphtha is highly flammable. When using
it, work in a well- ventilated area and wear rubber gloves and a respiratory mask. Good on crayons.
Alcohol is sold in many forms: isopropyl, methyl, wood, ethyl and denatured alcohol.
Is the familiar rubbing alcohol formulated for
external medicinal use.
It is also useful for removing resinous stains and for removing the gummy tar residue such as those in shoe polish and magic markers.
Denatured Alcohol: Is used for thinning shellac and for cleaning brushes used to apply shellac. It can be used to remove light pencil marks on wood. It can also be
used to clean certain permanent markers.
Is a blended mixture of two or more solvents. Acetone, amyl or ethyl acetate, keotone and toluene are common ingredients in lacquer thinners. Lacquer thinners are designed to thin lacquers and clean equipment used for lacquer finishing. It can soften and dissolve most paints even after they’ve hardened. It is highly effective at removing spray paint. However it can soften underlying paint and many plastics and vinyls.
A common ingredient in lacquer thinner is a useful solvent for working with plastics. It is effective in removing residue from plastic cements,
especially the cyanoacrylates (also
called instant or super
glues). It is the recommended thinner for polyester resins and fiberglass. It will melt plastic vinyl.
Acetone and lacquer thinner are useful for removing paint and varnish, but they will soften and dissolve many plastics like plexiglas.
solvents because the
acetone may attack the
bristles. Both acetone and lacquer thinner are highly flammable. And both release toxic fumes, so avoid inhaling them as much as possible.
Is the principle ingredient in most paint- removers and in heavy- duty brush cleaners. Sometimes it is combined with other ingredients
and sold as “graffiti remover.” It is effective in removing all finishes, but it too attacks and softens plastics. It can be hard on human skin, so wear rubber gloves when working with this solvent.
If you know the type of graffiti (crayon, spray paint, magic marker) go right to the type of solvent you need. Otherwise, work your way up the solvent list and see what works.
Technique is as important as the right solvent. You must use a CLEAN low- nap rag and keep using a clean part of the rag with each wipe. Otherwise as the graffiti softens, you’ll just end up smearing it around. See the Graffiti Removal Techniques Section for details
Source: City of Milwaukee
Last updated Aug 22, 2012