Vinyl Techniques: Preparing the Surface

“The biggest mistake is not prepping the surface,” says Jeff Stadelman, technical marketing manager for MACtac, a manufacturer of pressure sensitive adhesive products. “It’s so important to have a clean surface to put the adhesives down on. That’s definitely the number one error.”

No matter the substrate ­ glass or paint ­ and no matter the installation method ­ wet or dry – if you do not clean the substrate properly then you will end up with a contaminated surface that hinders the performance of the adhesive. In fact, experts say wetting solutions could cause even greater problems on unclean surfaces because the liquid will loosen up the contaminates and make it more of an issue.

Preparing the surface may seem like an obvious part of the vinyl installation process, but often time it is the most obvious steps that people miss. Whether it is hurried installers working by the job or inexperienced applicators who don’t understand the process, contaminated substrates are one of the leading causes of vinyl failure.

“People often want to skip the most basic step,” says Nathan Franzblau, founder of the Professional Decal Application Association, an association of independent certified vinyl installation companies. “If it is a trailer, then some people don’t want to take the time to clean it. If it is raining, then some people don’t want to take the time to dry off the rain drops. But that is a mistake. The materials are designed to work, but they are designed to work under the correct specifications.”

Choosing a Cleaning Solution 
As Franzblau notes, high-quality adhesives are designed to create an excellent bond on clean, smooth, weather-resistant surfaces that are free of grease, wax and silicone. But in order to achieve a long-lasting bond, the surfaces must be thoroughly prepared.

Experts recommend using isopropyl alcohol on the surface and wiping it with a clean cloth. Other cleaning agents could attack the paint or reduce the adhesive strength of the film.

“Some people tend to use ammonia-based cleaners to clean glass, but that leaves a residue on the window and can affect adhesive on the film,” says Lindsay Howard, a product specialist for Oracal, a vinyl manufacturer in Jacksonville, Fla. “It can either cause bubbles, which is a sign of outgassing occurring, or it can shorten the life of the adhesion itself.”

Outgassing is the vaporization of a solid or liquid. Outgassing can also occur in some plastics and insufficiently dried paints, resulting in adhesive failure of vinyl films applied over them. Fresh paint can also cause problems. Experts recommend allowing at least three weeks to pass before adhering film to paint that has been oven-dried or baked.

Likewise, if you use soap and water and do not clean it off adequately, then you could be leaving a thick layer of soap residue on the substrate. Unless the manufacturer specifies some incompatibility, isopropyl alcohol ensures a contaminant-free surface. It is strong enough to clean away any left over impurities that could hinder the adhesive, but not so strong that it will damage the paint.

Still, experts recommend testing the cleaning solvent on an inconspicuous area of the application surface first to check for potential damage. Experts recommend letting vehicles sit for 24 hours to ensure they are completely dry. Other substrates do not require this length of waiting time.

Special Considerations or Vehicles
When it comes to vehicles, there are additional issues to consider that you may not find with other substrates that are not exposed to the grit and grime of highway exposure. Many vinyl manufacturers recommend cleaning the vehicle with a commercial detergent and water. This is the best way to remove silicone substances and residues.

Heavy road grime or tar should be scrubbed with a solvent such as acetone. But take caution because if this solvent is used repeatedly it can cause damage to the paint. Always test for a negative reaction on an inconspicuous portion before using acetone.

If grease, oil, wax or any other grime is present, then the substrate must be scrubbed with a solvent and wiped with a soft, lint-free cloth before it dries. Isopropyl alcohol could be used afterward to ensure no residue from the detergent or acetone remain.

Wiping Down the Surface
Of course, it does little good to clean the surface with isopropyl alcohol if you are going to wipe it off with a dirty shop rag. Most experts do not recommend cloth towels for the final drying, either, because they often carry lint, which is a contaminant.

Domestic paper towels are often the best means of wiping down the surface because even clean shop rags can accumulate contaminates like wetting solutions or cleaning products. Moreover, it is best to use standard paper towels ­ not super absorbent or those with absorption pockets ­ because they may also carry contaminants that will get left behind on the surface.

Testing the Substrate
Just as you test the cleaning solution, it is also wise to test the materials on the substrate. When using materials that tend to outgas, such as polycarbonate or polystyrene products, Oracal recommends the following steps:

1. Clean the surface
2. Mount a piece of film to it
3. Store at 140 degrees Fahrenheit for 24 hours.

If bubbles formed after 24 hours, outgassing is still occurring. So, either treat the plastic with a heat source or store it for an extended period at room conditions.

Cleaning the Tools
While it seems elementary to work with clean tools, installers will often move from one job to the next quickly and not clean their tools. It is important to make sure there is no residue on the squeegees and other tools you are using that could be wiped onto the vinyl. Finally, all tools should be completely dry before you begin installation.

Once your surface is clean and dry you may proceed to the actual installation with assurance that the vinyl will adhere for its recommended lifetime.

For more information on vinyl application techniques, be sure to read other articles in this section. If you see a subject that is not addressed, then please send us an e-mail and we will consider adding a new article to this section.

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