Every tint job starts with a spray bottle. The solution in it lets you slide the film into place on the glass, then gets squeegeed out so the adhesive can grab. Get the mix wrong and the film either sticks too soon and creases, or stays slippery and takes days to dry. Here's what professionals use and why.
Baby shampoo is the favorite
When Window Film Magazine asked installers in 2012 what they use in their application solution, baby shampoo came first with 46.4% of answers. Joy dish soap was second at 17.9% and Ajax dish soap had 3.6%; the rest used something else, including commercial concentrates made for film.
Baby shampoo wins because it's mild and simple. It makes water slippery without the extras many dish soaps carry, such as lotions, degreasers and scents, which can leave a film on the glass or haze under the tint. It's also cheap and easy to find.
How much to use
You want water that feels slippery between your fingers, nothing more. A few drops of baby shampoo in a 32-ounce spray bottle is the usual starting point.
- Too little: the film grabs as soon as it touches the glass, so you can't slide it into position.
- Too much: the film keeps floating, the squeegee can't push all the water out, and the tint takes much longer to cure. Heavy soap can also leave a haze.
Use distilled or filtered water if your tap water is hard: minerals and grit end up trapped under the film as specks. Mix a fresh bottle for each job.
Two bottles: slip and tack
Many installers keep a second bottle of plain water (or with only a drop of soap), sometimes with a splash of rubbing alcohol. They spray it on the edges after positioning the film so the edges grab faster and don't lift. The main slip bottle is for the glass and the adhesive side of the film while you place it.
What not to spray on film
- Ammonia cleaners (many blue glass cleaners). Ammonia can damage tint and its adhesive. Clean tinted windows with an ammonia-free cleaner, and not at all for the first few days while the film cures.
- Heavily scented or moisturizing dish soaps. The additives are what cause haze.
- Anything abrasive on the film side. Use a soft cloth or a rubber squeegee, never paper towels on fresh film.
After the install
Some water always stays under the film at first. Small bubbles and a slightly cloudy look are normal and disappear as the film cures, usually within a few days in warm weather and up to a few weeks in cold weather. Don't roll car windows down for 3 to 5 days so the edges can set.
What next
- Watch the full process: how to tint car windows (video) and how to tint home windows (video).
- Replacing old tint first? See how to remove window tint.
- Rather have a pro do it? Here's how to pick a good tint shop.
Survey source: Window Film Magazine, "What soap/solution do you use for film installation?" (2012).
