Glass Facts


Today’s windshields are designed to help protect you in the case of an accident. They help keep passengers in the vehicle upon impact and keep the roof intact.

Your Windshield is a safety feature.

Protecting yourself and your vehicle is not just a matter of choice, it's the law.

What You Should Know About Your Car

Your car has been built not only as a means of transportation, but also to help protect you in the event of an accident. All repair work done to your car is regulated by Federal Motor Vehicle Safety Standards (FMVSS) to ensure that all parts and their installation meet the performance requirements that contribute to your safety. This includes all auto glass repairs and replacements.

Your windshield is secured to the body of your car by specially formulated glass adhesives that have been tested and approved to meet all applicable FMVSS requirements. At JN Phillips, we use only the highest quality adhesives and apply them to the manufacturers’ specifications.

What You Should Know About the Law

The National Traffic and Motor Vehicle Safety Act makes it illegal for anyone to return your car for use prior to all safety devices being fully operational. Since your windshield is a safety device, your car cannot be safely driven until the adhesive has had enough cure time to meet FMVSS performance requirements.


The windshield is an important component of the airbag deployment system.

Airbags rely on the windshield to deploy properly.

Your windshield is classified as a "safety device" because it provides structural strength to your vehicle and helps to keep passengers inside the car if an accident should occur. It supports the inflation and performance of passenger side airbags. The passenger side airbag deploys upward and off the windshield at speeds up to 200 mph. Federal Motor Vehicle Safety Standards require adhesives to be nearly six times stronger for cars with passenger side airbags.


We heat Sika brand adhesive to 180 degrees in special ovens so that you get the strongest seal possible.

Not all adhesives are the same.

The replacement windshield itself is just one part of a safe installation. In addition to factory-authorized glass, the quality of the adhesive is equally important. At JN Phillips, we use only premium Sika brand urethane adhesive. After conducting extensive research on all available windshield adhesives, we concluded that Sika delivers the strongest seal possible while keeping Safe Drive Away Time - the amount of time you have to wait before the adhesive is fully set to safely drive the vehicle - to a minimum.

The Sika products meet Federal Motor Vehicle Safety Standards and are widely used by high performance and luxury car makers all over the world, including BMW and Mercedes. Furthermore, Sika adhesive products are ideally suited for windshield replacements in our unpredictable New England climate.

The Sika adhesive must be heated to 180°. Despite the extra effort this requires, the results are worth it. In addition to enabling us to provide replacements that meet and exceed Federal Standards in a variety of weather and temperature conditions, both indoors and out, it allows us to deliver a safe replacement as quickly as possible. Once the adhesive is heated to 180°, it cures and sets faster than other products - making your car safe to drive in the shortest Safe Drive Away time possible.


Our technicians leave 1/16th of an inch of the old adhesive when replacing a windshield. It takes more time and skill to do this, but it provides the best bonding surface for the new adhesive.

What's so important about 1/16th of an inch?

Your windshield is one of your vehicle's most important safety features. In fact, doing a safe, certified replacement requires some pretty exacting procedures. Not only does the new adhesive have to be heated to 180°, the old adhesive has to be meticulously pared down to 1/16th of an inch and the glass has to fit perfectly into the pinchweld (the metal frame on the vehicle).

The reason why JN Phillips Auto Glass technicians cut the old adhesive to 1/16th of an inch is to provide the best possible bonding surface for the new adhesive and windshield. Removing too much adhesive or not enough adhesive does not allow for the best bonding surface and does not provide for the safest windshield replacement possible.


Safe Drive Away Time is the time it takes for the adhesive to cool and set properly. Safe Drive Away Times will vary based on temperature and humidity.

Safe Drive Away Time (SDAT)

SDAT is the amount of time required for your car to remain out of service until the new auto glass part can properly operate as a safety device. Cars with passenger side airbags require either more time or a faster acting auto glass adhesive to reach Safe Drive Away Time because of the additional strength necessary to support the deployment of the passenger side airbag. Federal Motor Vehicle Safety Standards require adhesives to be nearly six times stronger for cars with passenger side airbags.


Minor damage can often be repaired instead of needing to replace your windshield.

Repair or Replace Your Windshield?

A windshield repair is less time consuming and your vehicle will be safe to drive right away. A repair is also a less expensive alternative to a full replacement. Injecting a clear resin into the damaged area can repair chips, up to the size of a quarter, and cracks, up to six inches long. When the resin cures, you can barely detect where the damage was.


Every year, more than 15 million windshields are replaced in the U.S. That’s 600 million pounds of glass that goes into landfills. JN Phillips recycles every windshield we replace – we call it our GreenShield® Windshield Recycling Guarantee.

The 600,000,000 Pound Problem

A windshield is made of safety glass - - two layers of glass sandwiched around a layer of plastic. Separating these layers makes recycling a challenge, so most broken windshields that other auto glass companies replace end up in landfills. That adds up to about 600 million pounds of auto glass a year!

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