Driving in bad weather can sometimes be difficult, which is why it’s important to keep your
windshield as clean and clear as possible.
There are a variety of products on the market
today that claim to offer increased visibility, but how do you know if they work? We took
several of these windshield-treatment products through an 11-month test to evaluate how
they would stand up in rainy weather. Our test products included Rain-X, Rain Block, Rain
Clear (and its companion product, Glass Scrub), PPG Glass Treatment (also sold under the
name Aquapel) and NanoSafeguard. I started by dividing the windshield of a 2008 Tiffin
Phaeton motorhome (with a large one-piece windshield) into quadrants to test the
application and durability of each product. I then used the same method on dinghy vehicles
to try different products or to confirm the findings of the motorhome windshield test,
since the cars are driven every day.
Before application, it’s important to completely clean
your windshield (I used Stoner’s Invisible Glass aerosol and found it to be one of the best
glass cleaners on the market). It’s also a good idea to keep Viva paper towels or
microfiber towels handy. Remember that the application of these glass treatments must be
done in the shade. They contain ingredients that evaporate very quickly, and if you attempt
to apply them in direct sunlight, they will cure too quickly and cause problems during the
removal (“polishing”) process.
Rain-X and Rain Block
These two spray-on products are similar and easy
to apply. After thoroughly cleaning the windshield, simply spray Rain-X or Rain Block onto
a clean microfiber towel and wipe it on the glass, first in one direction, then in the
other with overlapping motions to ensure proper coverage. Then allow the surface to cure,
or haze, and wipe with a clean microfiber towel until the glass is clear. If you experience
any hazing with either Rain-X or Rain Block, sprinkle the windshield with water and it will
buff off and leave a sparkling clear surface. I noticed that at cooler temperatures (45-70
degrees F) both of these products were easier to apply and remove, leaving a streak-free
surface. Rain-X and Rain Block should not be used on plastic or paint, as damage could
occur to the surfaces. Neither product makes a claim as to how long they last, but they are
very inexpensive. The Wal-Mart price for a 16-ounce spray bottle of Rain-X was $7.49 and
the 17-ounce bottle of Rain Block was $6.99. They both worked well, but in order to blow
rain off the flat windshield of the motorhome, I found that driving speeds of 45 mph or
greater were required. The performance time for these products seemed fairly short at three
to six weeks, depending on the exposure time to the elements.
PPG Glass Treatment/Aquapel
These two products appear to be
identical but are sold under different trade names. Rather than a spray bottle, they are
packaged in small, one-time-use applicators. I found mine at O’Reilly Auto Parts at a cost
of $9.95 for an 8-milliliter single-use dispenser. The main claim of this product is that
it lasts six months. Our testing did not confirm the six-month durability claim, but it
does seem to last slightly longer than Rain-X or Rain Block. However, at $9.95 for 8
milliliters, it will take two to three applicators to treat a full-size motorhome
windshield, so you will have to weigh the cost/benefit of spending $30 per treatment versus
the lower cost of the other products. It is best to apply the PPG or Aquapel when the
ambient temperature is between 50 and 90 degrees F. It’s also important to not allow the
product to contact your skin, which is why it’s sold in an applicator format. Unlike the
Rain-X, this one should not be allowed to dry. Once you activate the applicator, wipe a
section of the glass with the built-in pad and then immediately wipe it dry with a paper
towel. For a motorhome windshield, you will have to repeat this several times to cover the
entire surface. I found this product easy to apply and it worked well at repelling rain
while driving.
Glass Science Rain Clear
and Glass Scrub
The next product we evaluated was from Glass Science. In addition to
the glass treatment, it includes a soft liquid or cream precleaner called Glass Scrub. I
liked Glass Scrub so much I used it several times throughout the testing process. Apply it
to a wet window and massage it onto the glass using a sponge. After cleaning the window,
simply rinse with water and then dry. I found it to be a great glass cleaner/stripper that
easily removes bugs and other contaminants. The only caution with this product is that it
has to be used with a wet sponge on a wet window, or scratching can occur. The Glass
Science kit also included a 5-ounce tube of Rain Clear rain repellent gel. Unlike the other
products mentioned so far, this one does not have a strong isopropyl alcohol smell. Its
application is simple yet slightly different from the others. The gel is placed onto a
microfiber towel and then rubbed onto the surface using overlapping motions. After covering
the window, turn the towel to a clean, unused section and polish it off until the window is
clear. As with the others, this is best applied in the shade. If you experience any
streaks, sprinkle the surface with water and wipe again with the microfiber towel or Viva
paper towels. Our test results indicated it slightly outlasts Rain-X, and at $6.99 from
Wal-Mart for the kit, it’s a good deal, too.
The final product in our test was NanoSafeguard, which I
ordered from the company via the Internet. The main attraction of this product was its
12-month durability claim. It was the most expensive product we tested – $36.95 for the
cleaner and sealant two-part system – but it could be considered worth the cost if it
worked a full year. Unlike the other test products that employed a very easy application
method, NanoSafeguard’s application process is more complicated. The first step in this
system is to clean the window using a mild soap and water, and dry the surface thoroughly.
Next, apply the auto-glass cleaner (using gloves) in a circular motion over the entire
window and dry using a lint-free microfiber towel. One precaution: Do not touch the window
between the cleaning process and the sealer application. To apply the sealer, use a small
sponge and wipe vertically over the entire window. All of this work should be done in the
shade, when the air temperature is less than 86 degrees F. Then allow the window to cure
for 30 minutes. After it is completely cured, polish it dry with a clean microfiber towel.
At this point, there is a two-hour waiting time before the windshield can be exposed to
water. Though the process was somewhat complicated, I was able to follow the directions
without too much difficulty. The cleaner and sealer come in 2.54-ounce packages, which is
about enough to treat one large motorhome windshield at a cost of $36. While it did seem to
last longer than the other products, the cost pushes the value part of the equation in the
wrong direction. Also, the complicated application method was another strike against it. In
summary, all of these window treatments were very effective at improving the ability to see
while driving in the rain. All of them cause rain to bead into smaller drops that are more
easily blown off the window while driving.
On one occasion during our test I experienced a
blown windshield wiper fuse while it was raining. Normally this would mean getting out of
the coach in the pouring rain to replace the fuse, or parking to wait out the weather. In
this case, the driver’s window had just been treated with rain repellent, so I was able to
drive with no wipers at all. As stated earlier, in order for the wind to blow off the small
rain droplets, the motorhome needs to be traveling at least 45 mph, but all of these
products make it easier to drive in the rain. We suggest finding one you can buy locally,
and using it often. From now on, I won’t be caught in the rain without it.
