Over the Edge

Edge peeling makes every sign maker’s list of top vinyl problems.

Failure to properly clean the substrate and failure to resqueegee the graphic after removing the application tape causes many edge-lifting problems. While graphics installers often get blamed if a problem occurs, application mistakes aren’t the only reasons.

Problems can even begin before the graphics leave the shop. Laminating a print before an ink has had time to fully cure can trap solvents. These trapped solvents can migrate through the printed vinyl film and attack the adhesive system.

Also be aware that some films are susceptible to solvent attack and require special processing. Be sure that, before you use a new film, you study the manufacturer’s literature and understand the limitations of the product. For example, some films cannot be printed to the edge and require that the printer allow for an unprinted border.

Following application, graphics often encounter grueling environmental conditions that work against the edges of a graphic. Every job is a little different. So make sure that you understand the potential problems with each application and plan accordingly.

Graphics for petroleum or chemical tankers, for example, are regularly subjected to spillage during filling. Films on these vehicles require overlaminates and edge sealing to prevent edge lifting (especially along the top edges of the graphic).

Graphics applied to roll-up rear or side doors take a pounding every time the doors are closed and require special care. Because wood doors can chip at the edges, applied films should always be edge sealed after they are trimmed.

The Customer Isn’t Always Right

Sometimes well-intentioned customers can unknowingly cause vinyl failures by the way they care for their graphics.

Some of the mistakes made in cleaning graphics include washing graphics with a high-pressure sprayer and cleaning with strong solvents and bug and tar remover.

Even hand waxing graphics can cause edge lifting because petroleum distillates in the wax can attack the exposed adhesive along the edge of the vinyl. Because firetrucks and emergency vehicles are frequently waxed, all edges should be edge sealed.

One of the best ways to prevent problems is to educate your customer after you install the graphics. As a suggestion, print a list of “Dos and Don’ts” explaining in detail everything that a customer should know about graphics care. Then respectfully review the list with him or her, so there are no misunderstandings.

Edge Sealer Prevents Edge Peeling

Many of the edge peeling problems can be avoided by using either a liquid edge sealer or an edge-sealing tape. That seems like a simple solution, so why don’t more sign makers do it? Excuses abound.

The reality is that edge-sealing graphics only takes an average of ten to fifteen minutes per vehicle. You don’t need to edge seal every exposed edge of the graphics; you just need to treat the potential problem spots on a vehicle (such as the gas filler door, underneath the wheel well, and along the seams of roll up door panels).

In many cases, if you ignore these potential problems, you could be asking for trouble. Here are some edge-sealing products that you should have in your vinyl application toolbox:

SEALITPEN: This unique, convenient product was developed by pinstriping legend “East Coast Artie” Schilling. While it looks like a felt-tipped highlighting marker, the SEALITPEN is filled with an acrylic clear coat. If you don’t want to contend with the mess involved in using a brush, this little pen is a neat way to apply edge sealer.

3M™ 3950 Edge Sealer: The original 3950 Edge Sealer was actually nothing more than 3M’s 3900 series solvent-based screen print clear coat. Back in my decal installing days, I would fill baby food jars with clear coat for edge sealing vinyl graphics. Instead of using the spherical fiber dabber that comes with the 3950 sealer, I prefer brushing clear coat with a #6 quill. With this brush, you can apply a thick 1/2-inch line of clear coat to seal the edges. Ideally, half of the clear coat will be on the vinyl graphic and the other half will be on the substrate.

3M™ Edge Sealing Tape 8914: For certain applications, edge sealing tape is a great alternative to using a liquid edge sealer. Sealing the edges of perforated window films is one of those applications.

The edges of perforated window films are vulnerable because dirt can collect in the perforations at the edges. To secure the edges, you need to edge seal. Using the edge-sealing tape is usually faster and cleaner than painting the edge of a perforated film with drippy edge-sealing liquid.

If wrapping a car, you should keep a roll of edge-sealing tape in your toolbox. The tape does more than sealing the edge of a vinyl film. It can also hold the edges of applied vinyl graphics securely in place.

Edge-sealing tape, which is available as either a glossy film or matte film, is similar to a linered overlaminating film with a highly aggressive adhesive. The tape is so aggressive that if you touch adhesive to adhesive, the tape is trashed. So be careful in handling it.

Other than that, the tape is easy to use. Just peel back the release liner exposing the adhesive and stick it. To prevent mishandling, only expose enough of the adhesive that you can comfortably handle.

The common sense rules that apply to using other pressure-sensitive materials also apply to using edge-sealing tape.

For example, even though the tape has a highly aggressive adhesive, it won’t stick to dirt. The application surface must be clean. This especially applies when you are using the tape to secure an edge under a wheel well.

When you’re done using the edge-sealing tape, secure the edge of the roll with masking tape and store the roll in a Ziploc® baggie to prevent the edges of the tape from being contaminated with dirt.

Perforated Window Films

Whether you’re applying perforated window films to store or vehicle windows, the graphic should be laminated and the edges should be sealed.

There are other dos and don’ts when installing these films.

Never overlap panels of performed film. Normally when you’re installing window graphics, you can overlap the vinyl at least 1⁄4-inch where the panels form a seam.

The reason is that these window films are comprised of thousands of little holes that represent 40 to 50 percent of the total area. Because the film has so many little holes, there’s approximately half as much adhesive on the overlapping sheet of vinyl film. The bottom graphics panel has roughly half as much surface area to stick to. This is a sure recipe for a vinyl failure in which edges are guaranteed to lift.

Instead butt the panels together. Then apply edge-sealing tape over the seam.

Edge-lifting problems can also occur where the vinyl touches the edge of the window. Always trim 1⁄4-inch of the film away from the edge. To minimize edge lifting, you can always edge seal the graphic with a commercial edge sealer (such as 3M 3950) or a clear coat (such as Frog Juice). If graphics start to peel at the edges, trim the peeled material and then edge seal the graphic.

I am also a believer that you should protect perforated window graphics with an overlaminate. In fact, some vinyl companies require it. This precludes using application fluid, because fluid would be trapped inside each little hole. In my experience, you don’t need application fluid to install these films.

In the real world, very few people will use an overlaminate. Failure to use an overlaminate on perforated window graphics films, however, can result in problems. Without an overlaminate, edges can lift and dirt can collect in the holes.

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 1⁄4-inch (6mm) space between the graphics and the frame. Most window graphics shouldn’t be edge-sealed. (Note: Perforated window-marking films are an exception.) Some manufacturers 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 (a #6 lettering quill). Using an overlaminate and an edge sealer prevents water from collecting in perforations, which can cause edge lifting.

Metallized Films

There are a number of reasons that installers should edge seal metallized films and reflective sheeting.

These films generally have a thicker profile. This thicker edge allows for an accumulation of dirt and waxes. That’s where a problem can start, as these contaminates can compromise the exposed adhesive on the edge of the graphic.

The problem is compounded at the edges because the metallization layer is also exposed. It’s at this point that galvanic corrosion can occur, especially if the graphic is used to decorate a boat used in salt water.

Many metallized films are rigid vinyls that are intended for flat applications only. Does that mean that there’s no way that you can apply these films to contours and other irregular shapes? Not at all.

But you do have to know what you’re doing. If you do the application wrong and stretch the film into an indentation or around a compound curve, the vinyl will likely stretch back. If you must form the film to an irregular shape, use heat to thermoform the film.

To ensure that the film stays down, apply Primer 94 adhesion promoter to the application surface prior to installing the graphics. After installing the graphics, edge seal the film.

Fixing Edge Peeling with Edge Sealer

I am frequently asked if you can reapply a pressure-sensitive vinyl graphic once it has started to peel. As my friends in New Jersey say, “Forget about it!”

Once the edges have lifted, dirt has already contaminated the adhesive. No, Super Glue won’t work, so don’t even think about trying it.

But don’t despair. All that’s needed is the old scalpel and a steady hand.

The scalpel that most professional decal installers use is an art knife, such as an X-ACTO® knife with a #11 blade, or you can use a stainless steel Olfa graphics knife with a 30-degree blade.

The first step is to cut the applied vinyl at a place where it has not yet lifted.

Be especially careful when cutting on a client’s vehicle. With a very light touch, cut away the failing material. If you have a brand new blade that’s razor sharp, all you should need to cut through a cast vinyl film is the weight of the knife. There is no reason to use any additional pressure.

If your blade is old and dull, immediately replace it with a brand new one. To compensate for its dullness, the natural tendency is to apply some muscle. That’s when you end up cutting into the substrate. It’s bad enough leaving a slight cut on the surface of the paint; it’s really bad if you cut down to the metal, where rust can begin.

After you remove the defective piece of vinyl, clean the surface and the edge of the applied graphics. First wash the substrate with a mild detergent and water. This removes any water-soluble contaminants.

The second step is to clean the surface along the edge of the graphic with isopropyl alcohol (IPA). This removes any oily grime.

Conclusion

Using edge sealer is just one step that you should take to ensure a successful application sans edge peeling.

There are other steps that you can take to minimize problems:

Graphics survey: Regardless of what type of job you’re bidding on, always conduct a site survey. Carefully inspect the condition of the substrate. If the surface is newly painted, make sure that you understand what type of paint was used and when it was painted. Outgassing paints can cause a variety of problems. Some paints contain additives that can inhibit adhesion.

Printing requirements: After printing, always wait at least twenty-four hours for the ink to outgas before lamination.

Substrate preparation: Clean the surface prior to application. Surface preparation will vary from one substrate to another. If you don’t know how to properly clean a surface, don’t be afraid to call your distributor for advice.

Temperature range: Vinyl films will fail if the application surface is too cold. Each film is a little different. Make sure that you know the minimum application temperature for the product that you are using.

Good squeegee pressure: Vinyl films are pressure-sensitive, which means that you need to use adequate pressure to initiate adhesive flow out.

Post heating: If you need to conform a pressure-sensitive film to an irregular surface, use heat to stretch the film. Once the film is applied, heat the film to secure it to the surface.

Resqueegee: Remove the application tape by pulling it off at a 180-degree angle against itself. After you remove an application tape, resqueegee the entire graphic, especially the edges.

My advice to you is to do the job right in the first place and minimize your problems and the time it takes to fix them. Let’s face it: no one makes money on rework!

By Jim Hingst

Photos: 3M, Hingst.