Preventing Vinyl Wall Decals Failures on Walls & Drywalls
New walls & drywalls must be primed and painted properly to ensure good adhesion of pressure-sensitive vinyl wall decals. You wouldn’t think that applying vinyl wall graphics to newly painted wall should be a problem. Of course, problems can and do happen. Especially when contractors rush to get the job done.
Commercial builders are often under a lot of pressure to deliver a building on time and face penalties when they miss deadlines. Sometimes painters will paint right over newly mudded drywall before it has a chance to dry. That traps moisture under the paint. If you apply vinyl wall decals to a wall that hasn’t dried properly, we can almost guarantee adhesion problems.”
And if you don’t wait for proper drying? Any trapped moisture in the wall or drywall can cause the paint to snap, crackle and pop. Well, sort of. The paint can peel, crack and blister. Moisture is the primary reason that paint does not stick to a wall or drywall. And when the paint doesn’t stick, neither do the vinyl wall decals.
Before priming you should also inspect the walls for any wall damage, such as nail pops and gouges, and any other imperfections in the coating of the taping compound over the seams, corners and nails. The drywall contractor will need to apply a skim coat over any of these problem areas. In many cases these imperfections will stick out like a sore thumb after the vinyl graphics are applied, especially if a gloss overlaminate is used.
Painting over a dusty wall can prevent the primer from bonding well to the wall surface. The best way to wipe down a wall is to dampen a lint-free rag with a mixture of 50% Isopropyl Alcohol and 50% water. Adding alcohol to the mixture speeds up the drying time.” After wiping down the walls, they are usually dry enough to paint after an hour.
New drywall must be primed before painting. There are no exceptions to this rule. Primers are essential for good paint adhesion – especially if you are painting with a latex paint.
Primers and sealers are not the same thing. Primers are designed so that the paint anchors to substrate. Sealers, on the other hand, form a barrier to prevent something from penetrating the surface.
Both the primer and the paint must be compatible. The general rule of thumb is that you can use either a latex or an oil-based primer with a latex paint; but you must use an oil-based primer with an oil-based paint.
Under no circumstances can you use a latex primer with an oil-based paint. The reason is that the latex primer will allow moisture to pass from the drywall. The oil-based paint will not allow the moisture to pass. The trapped moisture under the paint will cause blistering and peeling.
The reason that latex primers and paints breathe is that the molecules are much larger with wider spaces between the molecules. The wider spacing gives water vapor a passage way to slip through.
Does that mean that latex primers and paints are a better choice for drywall? Not necessarily so. Because oil/alkyd primers penetrate the surface of the drywall better than latex primers, they anchor better to the surface of the wall. Oil/alkyd primers also form a moisture barrier, which helps prevent moisture from getting behind the applied vinyl, degrading the adhesive and causing the graphics to peel. One downside of using oil/alkyd primers is that they take longer to dry, so you will have to wait longer between priming and painting.
Latex paints and primers have their advantages too. If you are concerned about the environment, the water-based primers and paints have low Volatile Organic Compounds. VOCs in oil based contribute 9% to the air pollution that forms smog.
After painting, we recommend waiting 72 hours for the primer to dry, before painting. Drying times, of course, can vary depending on ambient heat and humidity. To speed up the process, you can direct high volume fans over the surface and turn up the thermostat to 80º F (27º C).
After priming, the walls are ready for painting. After the primer is dry, apply two coats of a matte, satin or semi-gloss paint. The surfactants and colorants that make up darker paint colors tend to need longer periods to leach or outgas.
Light-colored flat finish paint is commonly used to decorate drywall surfaces, because it helps hide any imperfections in the drywall job. Painted with glossy paints, these imperfections stick out like the proverbial sore thumb.
Allow adequate drying time between the application of primer and the coats of paint. The paint will continue to outgas until it is completely cured. How long will that take? That depends on a number of factors, such as the type of paint used as well as the ambient temperature and humidity. To play it safe, we recommend waiting at least five days. If you apply wall decals to an outgassing paint, don’t be surprised if bubbles form underneath the vinyl.
Regardless of what brand and type of paint you’re using, make sure the paint is thoroughly cured before applying the vinyl graphics. “Read and Heed” the paint manufacturer’s recommendations regarding curing times. As a rule of thumb, allow the paint to cure for a week before applying any pressure-sensitive films. High humidity or cold temperatures can slow this curing process down, in which case, you’ll need to allow for additional curing time.
We suggest using paint from the same manufacturer as the primer, that way you can be sure that both components are matched for compatibility. All of the components must work together to achieve a good bond of between the paint, the primer and the wall surface. Equally important is that the primer and paint are well cured prior to application of the graphics. This is critical in ensuring that the vinyl adheres sufficiently to the wall. Proper curing is also important when it comes time to remove the graphics. Applying graphics to uncured paint can result in film tearing up the wallboard in the removal process.
You should take the time to “Test, Don’t Guess” and conduct a film adhesion test. Apply a piece of the vinyl to be used onto an inconspicuous place on the wall and see whether or not the graphics stay put. If the test sample is lifting at the edges, installer beware!
Additives, such as silicone, that prevent graffiti from adhering, also prevent a film from adhering.
CHOOSE THE RIGHT KIND OF PAINT
A wall’s paint or finish will greatly effect vinyl adhesion.. In the past few years, paint manufacturers have come out with paints that resist dirt and grime and are easy to clean. It just so happens that the properties that make these paints dirt resistant and cleanable also make them resistant to vinyl application. Other paints have come out with low VOC levels (Volatile Organic Compounds) to make them less harmful to the environment. Low VOC paints resist vinyl adhesion as well. Textured paints can also cause a problem for vinyl adhesion – similar to a brick wall.
PROPERLY PREPARE THE WALL
Peeling paint, scratches, gauges, and other imperfections will make a graphic look bad, and could keep a graphic from sticking. Any imperfections in a wall should be repaired before applying wall graphics. If the wall needs painting, make sure to clean off the wall before painting. If it’s an old wall with lots of dirt, oil, or other grime on it, you’ll need to make sure they are deep cleaned. Any imperfections in the paint will be visible underneath the vinyl and may cause it to peal up. If there are bumps in the paint, you will need to sand them down. Once a wall is painted, it’s best to wait at least one week for the paint to cure before applying vinyl.
RUN A TEST
Before you settle on the location of your wall graphic and the kind of vinyl you will use, it’s best to run a test to see what vinyl will work the best on the application surface. We have professional testing kits in our shop, and our team can help perform a vinyl adhesion test at your site. In order to achieve maximum adhesion, follow the following steps from 3M:
- Wipe down the wall two times with a mixture of 70% isopropyl alcohol and 30% water
- Wait 10 minutes
- Firmly apply strips of vinyl to be tested to the wall
- Wait 15 minutes
- Use a spring scale to measure the force it takes to remove the vinyl pulling it at 1″ per 5 seconds
- The vinyl should require above 400 grams of force to remove and below 1200.
GET AN EXPERIENCED VINYL INSTALLER
While there are vinyls that are very easy to apply, in general, vinyl application is a tricky process. It’s easy for someone with little experience to apply vinyl with wrinkles, or crooked on a wall. Different vinyls require different application techniques and equipment to install properly. An experienced installer will know what will work best in a particular situation. It’s best to have an experienced installer perform vinyl application, or to at least consult an experienced installer before application.
The lifespan of vinyl wall graphics will vary depending on a range of factors including: the kind of vinyl used, the amount of direct sunlight the vinyl is exposed to, the humidity, and more. Before you get vinyl graphics installed, make sure you are aware of how long they are supposed to last. If the steps above are followed, your vinyl wall graphics should not come off the wall prematurely.