What You Must Know When Applying Window Graphics

Learn the recommended procedure for applying vinyl graphics on windows.

By Jim Hingst

Vinyl window graphics provide retailers with several advantages over hand-painted graphics. Cost-effective machine-made graphics consistently reproduce a company’s image from one store location to another to another.  The durability of cast vinyl film is also much greater. Paint systems typically provide three years of durability. If the right films are used, processed according to the manufacturer’s specifications, and installed properly, vinyl graphics can provide five to seven years outdoor durability.  

Cast or Calendered Vinyl? Heat is just as damaging to vinyl films as UV light is. Prolonged high heat can prematurely age any vinyl film. But cast vinyl films are much more heat stable than calendered vinyl films. Most calendered vinyl films, especially the cheaper monomeric vinyl, just can’t stand the heat in warm climates. The picture of the calendered vinyl graphics in photo #1 was taken at a store location near Austin, TX on a window that was facing south. The baking heat of the summers in Texas caused the calendered vinyl graphics to crack and peel. Cast vinyl films are more expensive but they just last longer for demanding outdoor applications, such as window graphics.  

                                         Photo #1

If you are printing graphics, other factors can affect the outdoor durability of the finished product. Ink selection is one of those critical factors.  The outdoor durability of most digitally printed graphics is typically limited to two to three years.  Screen print vinyl inks can provide much longer service life, up to 5 to 7 years. Remember, though, that how well a graphic weathers depends on many environmental factors, such as exposure to UV light, heat, cleaning chemicals and air pollutants.

You can always improve the outdoor durability of a printed window graphic by protecting the image with a clear coat or an overlaminate.

Color Selection. White and light colors are much more noticeable on glass than dark colors. Using large expanses of black or very dark colors is not recommended. Dark colors can absorb the sun’s heat, causing vinyl-covered glass to rapidly expand while cooler areas stay rigid. With part of the window expanding and other areas contracting, glass breakage is possible. Large areas of dark color next to regions of very light, reflective tones can also cause heat gain and glass expansion. Films with extreme gray-scale differences can result in glass fatigue and early failures. I recommend breaking up a design with different hues rather than using severe contrasts of light and dark.

Surface Prep. Prepping the surface prior to application of window graphics is a multiple part procedure.  The first step is to wash the windows with a liquid detergent and water. After washing, rinse the surface with clean water and let the windows dry. Better yet, have your customer have the windows washed before you arrive on the job site.   

Next re-clean the glass with a mixture of water and isopropyl alcohol. Dry the surface using lint-free paper towels. Caution: don’t use such glass cleaners as Windex® that contain silicones, which can leave a residue that could inhibit adhesion. Some soaps, ammonia cleaners and solvents can also leave a residue that cause similar problems.

After washing, carefully inspect the windows. To clean windows speckled with dried paint, use a razor blade and re-wipe the windows with alcohol.

Application Temperature. Cold weather applications can be problematic. The recommended application temperature will vary from one vinyl film to the next. Always read the technical data sheet for the film used. Some films can be applied at temperatures of 40⁰ F and lower. The minimum application for other films is much high. If the surface temperature of the glass is too low, the adhesive will not flow out properly onto the glass and the film will not stick.

Wet or Dry Application? Dry application is the most effective way to install window graphics. In fact, most of the vinyl manufacturers will not warranty wet applications to glass. Anytime you add anything between the adhesive on the vinyl film and the substrate you are contaminating the adhesive to some degree.  And that contamination can contribute to adhesion failure.

As a former installation subcontractor, I never liked applying graphics wet, because it slowed you down.  Anything that slows you down is money out of your pocket.

For trouble-free applications, select the right film. Some films feature low-tack, repositionable adhesives that permit an installer to apply vinyl graphics to windows without application fluid.

Many sign makers refuse to attempt dry applications for fear of trapping small air bubbles. Squeegee marks on the adhesive side of the film are also common, but neither is a problem. Tiny air bubbles will breathe out of the film after a week of warm weather. Don’t speed up the process by popping these bubbles with a pin. The light shining through the pinholes will be visible from inside the store. Let time and temperature fix the problem. Squeegee marks also vanish once the adhesive has time to flow out.

To prevent bubbles, use professional-grade application tools, vinyl films with repositionable adhesives and proper installation techniques. Here are a few tips to help you:

• Always sharpen the squeegee’s edge before beginning the application, making sure the edge is free of nicks. Small nicks generate small bubbles.

• When masking, be careful. Wrinkles and bubbles in the application tape create wrinkles and bubbles in the applied graphic.

• When squeegeeing, use firm pressure and overlap your strokes.

• When removing application tape, pull it 180° against itself, taking care not to pull the vinyl from the window surface.

• After removing the application tape, always re-squeegee the graphic.  You will note that in my photos, I am using a Teflon squeegee. You can also cover a standard squeegee with a low friction sleeve. Or use a squeegee with a felt covered edge.

Certain circumstances require wet applications. Aggressive adhesive systems make vinyl installation difficult, if not impossible. Hot weather also complicates matters. If a window approaches 100°F, the adhesive becomes unmanageable and, thus, repositioning is impossible. Misting the surface with clean water cools the surface. As the water evaporates, the temperature can drop 20° to 40°F.

If you must do a wet application, use a commercial application fluid instead of a homemade concoction. Despite hearsay, Windex is not an acceptable application fluid.

Application Sequence. Below is a series of photos which corresponds to my step-by-step application procedure.

 Step 1: Are you having difficulty seeing the cut vinyl copy? Make weeding easier by very lightly rubbing chalk dust from a pounce pad over the surface of the vinyl.

 

Step 2: Black chalk dust works great with white and many other vinyl colors.  It isn’t much help with black vinyl.  In these cases, use white chalk dust. Note: using black and dark colors is not recommended for window applications.

Step 3: With the matrix weeded from the cut vinyl, it’s time to apply the application tape.

Step 4: In the winter low humidity can cause static problems with application films.  In these cases, lightly mist the non-adhesive side of the film with Rapidtac to kill the electric charge.



Step 5: Take care in applying the application film to the cut vinyl graphics. If you get wrinkles or bubbles in the application film, you will likely get wrinkles or bubbles in the applied lettering. (Note: the reason that you can’t see the AT60 application film in the photo is that it is crystal clear.)

Step 6: Before applying the graphics, take care to thoroughly clean the glass using Isopropyl Alcohol (IPA).  Windex is not an acceptable cleaner, because it contains surfactants and silicone which can cause adhesion problems. 

Step 7: After prepping the window, use two pieces of masking tape to position the graphic on the window. Be sure to double check your measurements before applying the vinyl.

Step 8: To aid the application of the graphic, you can use a side hinge, taping the marking in place using 2” masking tape.

Step 9: Next, remove some of the release liner exposing the adhesive side of the vinyl letters.

Step 10: Using overlapping strokes, squeegee the graphic into place.

Step 11: After squeegeeing the lettering in place, carefully remove the application film, pulling it from the surface of the applied graphic at a 180⁰ angle.

Step 12:  When performing any type of application, always re-squeegee the entire applied graphic to ensure that the lettering adheres well and to prevent any edge curling.

When installing window graphics, don’t apply vinyl over rubber gaskets or on the window frame. Film applied to these areas usually falls off. Allow at least a 1⁄8-in. space between the graphics and frame. Most window graphics shouldn’t be edge-sealed (perforated window-marking films are an exception). Some manufacturers, such as Avery, recommend protecting these graphics with an overlaminate. To complete the installation, seal the film’s edges by painting on the sealer with a fine-tip narrow brush, such as a #4 lettering quill. Using an overlaminate and edge sealer prevents water from collecting in perforations, which can cause edge lifting.

NOTE: Are you having problems in applying frosted window graphics films? Read my suggestions in my story: Transferring and Applying Frosted Window Graphics Films

Also read my story on how window graphics and window displays help increase store traffic and generate impulse buys: Window Graphics and Window Displays

RECOMMENDED VINYL GRAPHICS APPLICATION TOOLS

SEALITPEN

● Felt tipped marker filled with acrylic clear coat. 
● Use the SEALITPEN to edge seal a vinyl graphic. 
● A clean way to apply edge sealer - no brush required. 

3M Brand 3950 Edge Sealer

● Seals exposed edges of vinyl graphics.

● Prevents pressure-sensitive vinyl films from lifting resulting from environmental exposure or cleaning.

● Easy to apply clear edge sealer with a small artist’s paint brush or sign maker’s quill.

● Essential sealer for any professional graphics installer.

● Suitable for graphics applications in temperatures from 50°F to 100°F.

3M Tape Primer 94 1/2 Pint 8oz For Vinyl

● Promotes adhesion of all brands of pressure sensitive vinyl films and 3M™ VHB™ Tape.

● Use when vinyl graphics will be stretched into concave areas.

● Use complex vehicle contours, such as bumpers.

● For use on difficult to stick to and low energy surfaces such polyethylene, polypropylene, ABS, PET/PBT blends, concrete, wood, glass, metal and painted metal surfaces.

● Dries to a clear finish.

● Cleans up with isopropyl alcohol.

Steinel HG 2510 ESD Programmable IntelliTemp Heat Gun with a LDC Display 

● Temperature range: 120°F - 1200°F.
● LCD display enables temperature selection in 10°F increments
● Ideal for applications requiring precision control.

RollePro Vinyl Application Roller

● Using a RollePro eliminates the need to puncturing holes in vinyl films. No need to use a rivet brush. 

● Reduces the speed of applying vinyl graphics over rivets up to 50%. 

● Install vinyl graphics faster to make more money.

RollePro™ Textured Surface Kit

The RollePro™ Textured Surface Kit includes a standard handle, an original wheel and a high temperature wheel. The high temperature wheel can be used on a variety of surfaces such as brick and concrete.



3M Air Release Tool

• Needle point punctures bubbles under vinyl graphics to remove entrapped air.          • Retractable point protects graphics installer from puncturing himself. 

 

Car Wrap Magnets

• Vinyl wrap magnets hold vinyl graphic in place for easier application.

• Replaces masking tape in positioning graphics.

Vinyl Application Videos

Squeegee Technique. Nothing is more basic in vinyl application than the squeegee. But some squeegees work better than others. And there are right ways and wrong ways to use this simple tool. This video clip reviews squeegee selection, squeegee care and squeegee technique. Click to Link

Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link

Application of Window Graphics. Installing vinyl graphics on glass can be challenging, because the adhesive aggressively grabs onto this high energy surface. Repositioning graphics on window is generally difficult, if not impossible. This instructional video explains how to dry apply window graphics right the first time. It also describes the necessary steps required for surface preparation. Click to Link

Transferring Frosted Window Graphics Films.  Because frosted window films are highly textured, transferring cut vinyl graphics can be problematic. This video provides direction in selection of the right application tape and how to apply these films quickly, easily and without problems. Click to Link

3-Step Surface Prep. This instructional video describes how to properly clean the surface of a vehicle before applying pressure sensitive vinyl graphics to a trailer or doing a full wrap of a car or van. This three step surface prep involves detergent washing, solvent cleaning and a final wipe down with IPA. Click to Link

Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free.  Click to Link

Vinyl Application to Corrugations. Learn how to apply vinyl graphics to corrugations in a relaxed state. Forcing films into the valleys of corrugations puts too much mechanical stress on the film. Sooner or later, the vinyl will lift or tent in valleys. Click to Link

Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link

About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.

Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer.  Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.

Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for  publications, such as  Signs Canada, SignCraft,  Signs of the Times, Screen Printing, Sign and Digital Graphics and  Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published.  Vinyl Sign Techniques is available at sign supply distributors and at Amazon. 

Slides of Jim's Artwork

© 2016 Jim Hingst