Windshield Water Repellent: Rain X vs Car Wax

Windshield Water Repellent

Windshield water repellent makes water bead up on your windshield, increasing visibility when driving in rain or snow.  This is similar to the effect that you see with freshly waxed metal surfaces on your car.  Visibility problems occur when water spreads out over the surface of your windshield.  Water repellent makes water try to minimize its contact with your windshield.  The result: water pulls into tight droplets that don't interfere as much with your visibility.  Another benefit: water will blow off of your windshield without even using your windshield wipers.  Water repellent also makes it easier for your windshield wipers to push water off of the windshield.

There are two ways to get the benefit of water repellent for your windshield: Rain X or car wax.

Windshield Water Repellent with Rain X or Car Wax
Image Source: Dr. Penny Pincher

Rain X Windshield Water Repellent

Rain X Windshield Treatment

There are a couple of Rain X products that you can put on your windshield to repel water to improve visibility in rain or snow.  After application of Rain X, water beads up on the windshield instead of spreading across the windshield.  I found that I don't need to use my windshield wipers unless it is raining fairly hard.  Water stays beaded up and even blows off of the windshield while driving.

Rain X Windshield Treatment provides the water repellent treatment for your windshield.  This liquid compound is applied to the windshield like car wax.  After it hazes over, it wipes off and leaves your windshield water repellent for a few months.

Rain X 2 in 1

Rain X 2 in 1 Glass Cleaner and Rain Repellent sprays on and wipes off just like glass cleaner such as Windex.  Like the original Rain X formula, Rain X 2 in 1 also leaves your windshield water repellent for better visibility in wet weather.

Use Car Wax as Windshield Water Repellent

When I used the original Rain X formula, it reminded me a lot of car wax.  In fact, the effect of Rain X on a windshield is very similar to the effect of car wax on metal.  I decided to try applying car wax to my windshield to see if it would provide the same water repellent effect as Rain X.  My bottle of Rain X was long empty, and my windshield was making it very hard to see if there was any rain at all.

Use Synthetic Car Wax as Windshield Rain Repellent
Image Source: Dr. Penny Pincher

I was a little nervous about trying car wax on my windshield.  My fear was that the wax would get hazy and then be very hard to remove from the windshield.  This turned out not to be the case- the wax went on easily and came off easily.  I used Meguiars Tech Wax 2.0, which is a full synthetic wax.




I pulled my car in the garage with the windshield damp from driving in a light rain.  I placed a small amount of synthetic car wax on a clean cloth and applied it to one half of the windshield in the same manner as waxing a car.  I added a bit more wax to my rag and waxed the other half of the windshield.  I had a light coat of wax evenly over the entire windshield.  I allowed the wax to try and haze over for about 10 minutes.  The wax came off of the glass windshield even easier than it comes off of the metal of the car body.  It was very easy to remove the wax and it left the windshield looking very clean.  The windshield felt very slippery to the touch.

How to use car wax as windshield water repellent:
Step 1. Clean your windshield and moisten it with a little water
Step 2. Apply a light coat of car wax to your windshield
Step 3. Let the wax haze over for about 10 minutes
Step 4. Remove the car wax with a clean cloth by hand- use a circular buffing pattern

Of course, I had to take the car for a drive in the rain to see how well car wax works as windshield water repellent.

Windshield with Water Repellent from Car Wax
Image Source: Dr. Penny Pincher

The car wax worked great as water repellent.  The water beaded up and blew off of the windshield without even turning on the windshield wipers.  What an improvement!  The result is very similar to using Rain X.

If you are using car wax on your windshield, avoid using any wax that has abrasives to avoid making tiny scratches in your windshield.  Also, I would recommend buffing lightly by hand rather than using a power orbital buffer.  Again, this is to avoid scratching your windshield.  A final note, if you have small rock chips or scratches in your windshield, the wax can fill these in and turn white, making these imperfections more noticeable.

My windshield is in good condition, with only one very minor windshield rock chip.  Overall, I think the results of using car wax as windshield water repellent worked very well.

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