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Whether
you’re wrapping an HHR or installing vinyl graphics on a new police
cruiser, proper surface preparation is a key to satisfaction. Any
substrate must be clean and dry before applying vinyl graphics. With
vehicles, there are unique surface preparation factors that must be
taken into account. Some of these factors are dirt, waxes, paint, and
polycarbonates.
Dust and Dirt
Trapped dust is one of the most common causes
of bubbles in applied vinyl. Make sure your surface is clean, dry, and
dust free before applying your stickers. For removal of grease, oil,
wax, and so on, Avery recommends scrubbing with a solvent wipe (Xylene,
heptane, ethylacetate or denatured alcohol) with the following
caution: "After proper cleaning, the substrate surface should be
thoroughly wiped using a clean rag saturated with a cleaner such as
DuPont’s Prep-Sol Brand Solvent 3919S, Rapid Prep by Rapid Tac or
Sherwin Williams R7K-156. NOTE: Other solvents such as IPA (isopropyl
alcohol), VM&P Naptha, Xylol or lacquer thinner may also be used
instead of DuPont 3919S. However, care should be taken to assure that
the final dry wiping is accomplished prior to the solvent
evaporating.""
Wax and Surface Coatings
Some auto dealers add silicone-based coatings
to new vehicles during dealer prep. Silicone can migrate into the
vinyl’s adhesive and cause it to fail. When applying graphics to a
newly-delivered vehicle, Oracal recommends you "...contact your local
dealer for the best way to remove (any silicone based) coating.
Usually a wash with a commercial cleaner and an isopropyl alcohol wipe
down will do the job."
Uncured Paint
A slightly less obvious problem is uncured
paint. Many automotive grade paints take time to completely outgas. As
the paint solvents outgas, they deteriorate the vinyl’s adhesive bond
and lead to failure of the graphic. On the other hand, vinyl can be
applied to baked enamel paints as soon as they’re dry. If the car has
been painted by a local body shop, make sure you know what kind of
paint process they use.
Polycarbonates & Bubbles
A similar problem comes from applying vinyl to
a new polycarbonate fixture, such as a headlight or tail light cover.
New polycarbonate fittings need time to outgas. If vinyl is installed
too quickly, bubbles will emerge under the film. This can be a
baffling problem because the graphic looks perfect when installed. At
the very least, a new Lexan® or other polycarbonate surface should be
cleaned with ISA before applying vinyl. But that may not be
sufficient.
Oracal recommends: "Polycarbonate should be baked 4-24 hours at 250°
in an air-circulating oven before applying pressure sensitive vinyls.
In some applications, flaming can be used."
Avery suggests testing a small sample of Avery vinyl on the
polycarbonate and baking it for 18 to 24 hours at 149° to 158°F. If
outgassing occurs during this test, application with Avery vinyl is
not recommended.
The wisest course is to follow the recommendations based on the brand
of vinyl you use. So stock up on alcohol wipes and remember the five
P’s: Proper Preparation Prevents Poor Performance! |
