What Is Winter Coating On A Windshield And How Long Does It Last?

Winter is almost upon us in the Northern Hemisphere, bringing with it extra challenges for drivers. You'll need to decide how long to let your car warm up before driving and put together a winter-focused emergency kit before it gets too cold. You can expect diminished performance in winter whether your car is electric or powered by internal combustion, but no car is safe to drive with a windshield obscured by ice and frost. 

Five Northeastern states have laws requiring you to clear snow and ice from your car before driving, according to FindLaw: New Jersey, Rhode Island, Pennsylvania, Connecticut, and New Hampshire. And Minnesota's legal code states, "No person shall drive any motor vehicle with the windshield or front side windows covered with steam or frost to such an extent as to prevent proper vision." But you shouldn't need the threat of a citation to make you clear your windshield before driving. 

A broom or snow brush is the best way to clear accumulated snow from your hood and roof, and most drivers use a plastic scraper to clear their windshields. Or you can use a product like CRC ice-off spray. 

But you also can treat your windshield before the worst winter weather arrives. Hydrophobic ceramic glass treatments such as Cerakote make your windshield less likely to accumulate ice and frost, and will be effective for two to five years depending on climate, while wax-based treatments like Rain-X may wear off in about six weeks; more on this below.

Treating your windshield with ceramic-based coatings is a simple process you can do yourself, although you can certainly hire a professional to do it for you. Start by moving your car into a clean spot out of direct sunlight and cleaning your car's glass thoroughly of all dirt and streaks; this ensures that the coating adheres well. 

Apply the ceramic coating in two phases. First, working first horizontally or vertically, wiping slowly with a slight overlap and then going in the opposite direction with a fresh applicator. When you're done applying the treatment, let it sit for five minutes to allow the coating to form beads on your windshield. Use one side of a microfiber cloth to smooth out the coating, then switch to the other side to buff it using a circular motion.

Let the coating dry for at least two hours before driving to allow the treatment to cure. Then wait at least 24 hours before using your wipers or letting moisture come into contact with the windshield. 

Some windshield treatments don't specifically claim to keep ice and frost off of your windshield, but are effective in making rain bead and run off the glass without obscuring your vision. Many of them are tried and true when it comes to repelling water from glass, and this should help whether the water is in liquid or solid form. Says Supreme-X Mobile Auto Detailing of Sparks, Nevada: "They create a hydrophobic surface, preventing moisture from sticking and freezing, thus keeping your windows clear and frost-free." 

Supreme-X recommends the kit shown above from Invisible Glass, which you can buy for $74.99 from Amazon, where it averages 4.5 out of 5 stars. It includes a 3.38-ounce bottle of glass stripper with applicator sponge, a 19-ounce aerosol can of glass cleaner, and a 1-ounce bottle of professional-quality ceramic coating with an applicator, two microfiber cloths, and a pair of nitrile gloves to protect your hands. Supreme-X says Invisible Glass can protect your windshield for as long as two years, but admits the useful life of an application will be closer to one year if you live in a location with severe winters. 

Scott HD conducted a six-month test of 28 windshield treatments for effectiveness over time, and found that most of the products lost much of their effectiveness after two to three months. Rain-X was still somewhat effective near the end of the six months, far outperforming its manufacturer's claims. Another strong performer was Griot three-in-one wax and silicone dioxide treatment, which has an average rating of 4.6 stars from more than 2,000 Amazon buyers. 

Invisible Glass was not included in the 28-way test, but the manufacturer claims it will be effective for up to a year. The Invisible Glass protectant with applicator kit is also available on Amazon without the stripper or cleaner for $59.99, currently on sale for $53.13, with an average rating of 4.3 stars. 

Another highly rated option is Blask Graphene hydrophobic ceramic spray, which retails on Amazon for $31.99 for a 16.9-ounce bottle and has an average rating of 4.4 stars. Blask touts it as an effective protectant for your car's painted surfaces as well, although the manufacturer makes no claims as to how long it lasts.