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Window of Opportunity? Glass Installation…

If you thought glass installation would be a simple, trouble-free profit center, think again. Properly replacing glass is just as complicated as properly repairing collision


If we think we have it bad … tough competition,
controls by others outside the industry and liability exposure,
just look at the glass industry and its world.

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Afterward, be happy you’re in the collision
repair business!

Unfortunately for us, the glass industry is
going through what our industry is apparently heading toward.
Consolidation will ultimately affect pricing of our services,
decrease our repair turn around times and increase competition
of convenience.

To think … some time long, long ago,
the retail list price for glass was really the retail list price
for glass.

If you’re thinking about doing your own glass
work and you’ve weighed all the factors, I have two statements
for you. If you answer "true" to both, then it probably
is a necessary strategy for your future:

  1. Your volume of glass work internally and/or externally makes
    this venture profitable.

  2. No one in your area has the proper skills, or they don’t provide
    you quality service.

Business Decisions

Taking on glass installation would be no different than any other
business venture. You need to have a reliable and competitive
wholesale source, a staff with the proper skills and certifications,
up-to-date tools and materials, and the time to properly manage
the business. Without all of these in place, you surely wouldn’t
consider entering into this arena, would you?


Keep in mind, even if you elect not to enter the glass-installation
business, you still need to understand the procedures necessary
for proper installations and the liability you continue to incur.
Whether you actually do the work internally or sublet it to another
company, in most cases, you’re still liable. Unless the glass
installation is direct billed to and the contract is directed
by the insurer, the vehicle owner has a contract with you, not
with whom you elected to do the installation. For this reason,
it’s important that you’re very well informed – even when contracting
someone to perform the glass work for you.


To do this, let’s examine some areas of consideration.

The Source

Your first area of consideration is your glass source. It’ll be
difficult to achieve discounts on glass to a competitive level
with normal, small purchase volumes. In fact, most collision repair
facilities have found they can establish contracts with outside
vendors to do the complete job, including the cost of the glass,
for what they can buy the glass for. Their profit, then, is realized
through an acceptable mark up on the glass plus the installation
labor and materials.


This doesn’t solve the problem if the source is unreliable or
you just don’t receive the service you need. In these cases, you
may elect to re-examine your sources again. Send a bid letter
explaining your needs to all vendors, and ask them to bid on your
account. Include your last year’s annual purchases in glass replacement
and other glass needs, plus set a contract time frame, such as
one year. This gives vendors an idea of your anticipated volume
and some security in their investment for your account.

Glass Standards

The role of glass today is not just to stop bugs from getting
into our eyes. Glass plays an important structural role as well,
and this role is predicted to increase in the future.


To help ensure safe installations – along with safety in general
– The National Highway Transportation Safety Administration (NHTSA)
develops Motor Vehicle Safety Standards (MVSS) for vehicles sold
in or imported to the United States. The windshield and its installation
method (original manufacturing) must be able to pass two performance
standards: MVSS 212 and MVSS 216. These two tests, even though
they’re designed for vehicle manufacturers, have also become the
standard for aftermarket repairs since we are – by default – contracted
to restore the vehicle to pre-accident condition.

  • MVSS 212 – Commonly called the windshield retention test,
    MVSS 212 requires the windshield to keep the front-seat occupants
    from exiting through the windshield in a frontal collision. The
    test is performed at 30 mph into a fixed barrier. The windshield
    must maintain at least a 75 percent perimeter after unrestrained
    occupants hit the windshield.
  • MVSS 216 – Commonly called the roll-over test, MVSS 216 requires
    the windshield and A-pillar area to withstand 1.5 times the weight
    of the vehicle directed downward at the front of the roof without
    crushing more than 5 inches during the two-minute test. Since
    roll-overs vary greatly, this test is performed with a crushing
    panel applied to the front of the roof. The vehicle must be secured
    so the suspension isn’t a factor, and all other windows are closed,
    such as sunroofs and doors.

  • MVSS 208 – This is another standard that indirectly affects
    the replacement of windshields. Although this standard is designed
    for passenger air-bag deployment, in the specification it acknowledges
    that the passenger air bags designed to rebound off the windshield
    for proper positioning will do so with a force of 300 pounds per
    square inch. Therefore, for proper placement of the passenger
    air bags, the windshield must be able to withstand this force
    without being pushed out.

    The preparation, method of installation, adhesives used, temperature
    and humidity during installation, and the proper cure time all
    directly affect whether the installation will meet the above three
    safety standards. For these reasons, it’s very important to distinguish
    between glass installations from the past and what’s required
    today. Even auto manufacturers have specific requirements that
    differ from each other.

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    The Tools

    Today, specialty tools have become commonplace for glass installations.
    Electric or pneumatic power cutting tools, inflatable bags and
    suction cups have replaced the cold knife and piano wire in many
    applications. These methods allow for the removal of some very
    difficult glass designs, but they require training and practice
    – otherwise, the glass and interior trim may be damaged.

    Even with conventional tools, training and understanding are needed.
    One common mistake made when using the common cold knife is not
    properly sharpening the blades before using them. It’s also important
    that the blade be positioned properly when pulling it through
    the urethane. The cutting blade section should rest as close and
    parallel to the glass surface as possible when cutting. When this
    isn’t accomplished, the blade or glass breaks and pulls through
    the urethane like you’re pulling against a team of horses.


    Materials and Preparation

    Before windshield retention standards were implemented, most windshields
    were installed with butyl tape or set in a rubber gasket. The
    primary purpose of these methods was to keep the windshield from
    leaking and to set it in something flexible so when the vehicle
    body flexed, the windshield didn’t crack.

    Butyl tape supplies a bonding strength of approximately 13 psi.
    This, of course, is far from the passenger air-bag deployment
    pressure placed on the windshield in the MVSS 208. However, it’s
    possible for a butyl tape installation to pass the MVSS 212.


    Since the Motor Vehicle Safety Standards don’t provide a minimum
    strength for adhesives (except by indirect means), auto manufacturers
    have their own standards or OEM specifications. The OEM-approved
    urethane adhesives today supply more than 600 psi of tensile strength,
    and there hasn’t been any adverse effect identified with using
    an adhesive that’s too strong, just too weak.

    Unfortunately, there are other factors that affect the installation
    besides the adhesive specifications. These include surface preparation,
    curing time, temperature, humidity and the size of the bonding
    surface. As it’s been stated, "A chain is only as strong
    as its weakest link." Any one of these can easily cause the
    installation to fail.

    Installation Method

    There are two basic types of installations: full cutout and partial
    cutout (Figure 1-1). Note: Auto manufacturers may have specific
    recommendations for the type of installation they approve, and
    it’s important to follow these recommendations as outlined.

    The full-cutout method removes all or all but a very thin layer
    of the OEM adhesive, while the partial-cutout method leaves the
    majority of the OEM adhesive in place.


    Generally, auto manufacturers will have guidelines regarding whether
    a partial-cutout method is approved for their vehicles but, in
    many cases, the condition of the pinchweld area will dictate a
    full-cutout method, even though the manufacturer allows otherwise.
    If the pinchweld area is damaged, it’s likely the adhesive will
    be removed completely in the repair area. This then requires a
    full-cutout method.

    Using the partial-cutout method (if approved) is best advised
    immediately after cutting out the old windshield. This ensures
    a very clean surface for bonding. If the windshield isn’t installed
    immediately, it’s best to cut another layer to expose a freshly
    cut urethane bonding area or perform a full-cutout method.


    A special note should also be made in regard to repair work in
    these areas. All metal work areas where an adhesive will be applied
    should be "metal finished." In these areas, no plastic
    filler should be used since its adhesion characteristics are lower
    than urethane adhesive. Also during refinishing, pinchwelds should
    be primed with the appropriate epoxy or self-etching primer but
    generally not topcoated or cleared. Again, the paint system could
    be considered the weakest link.

    Surface Preparation

    Proper preparation before installation is critical. The glass
    surface where the adhesive is to be applied must be properly cleaned
    – or the adhesive won’t be effective. This includes using a complete
    system designed by the adhesive manufacturer. We’ve finally learned
    not to intermix systems with our refinishing products, and it’s
    extremely important to stay within a system when preparing glass
    for installation too.


    The cleaning begins with a glass cleaner designed for the system,
    which won’t leave a film or residue. Even a finger print in the
    adhesive area can cause the adhesive to fail during testing, so
    this step must not be overlooked.

    Some systems will require a special primer be applied to the glass.
    This primer may or may not be the same primer recommended on the
    pinchweld area. In some applications, an additional ultraviolet
    (UV) protection coating may be called for if the glass doesn’t
    already have it applied.

    In the pinchweld area, special primers are designed for any bare
    areas before application of the adhesives. Any loose original
    adhesive must be removed, and the original urethane must be clean.
    Since urethane can be porous, it’s not normally recommended to
    use a solvent-type cleaner. Water can be used, but the area must
    be dry before installation. Again, the adhesive manufacturer will
    have specific recommendations for these conditions.


    Curing Times

    You’ve probably heard phrases such as "ultimate curing time"
    and "safe drive-away time" when discussing adhesives.
    But be very careful when considering what these phrases actually
    mean; they may not be referring to what you think.

    The ultimate cure time is simply the time it takes the adhesive
    to fully cure. The safe drive-away time refers to the time it
    takes to reach or exceed MVSS 212. Wait a minute, what about the
    other two standards? Because these phrases are often used too
    loosely, they may imply something you don’t mean. Make sure to
    ask specific questions.


    Also, the ultimate cure time and the safe drive-away time are
    sometimes ignored to facilitate speedy delivery of the vehicle
    back to the owner. Some adhesive advertising may even loosely
    use these terms for a competitive advantage.

    Keep in mind, if you install (or have installed) a windshield
    and the adhesive isn’t totally cured or doesn’t meet all three
    safety standards and you deliver the vehicle to the customer,
    you’ve exposed yourself and the company to an extreme liability

    If the customer (or employees, for that matter) has an accident
    in the vehicle and the adhesive hasn’t properly cured to exceed
    these standards, this installation could cause personal injury
    or death. If this happens – whether you personally installed the
    windshield, had an employee do it or had another company do it
    – you are liable. You may be asking yourself, "What’s the
    chance of the vehicle getting into another collision on the way
    home?" It’s not worth the risk, believe me.


    Temperature and Humidity

    Different adhesives are designed for different weather conditions.
    Some may be single component while others may be two component.
    They all have a specific range of use for which they were designed,
    so it’s important to know the specifics of all products in the
    system and make sure they’re used accordingly. It’s also recommended
    to allow adhesives to dry naturally unless specifically designated
    otherwise. Heating units normally aren’t advised for most adhesives.

    Not only is temperature a factor, but so is humidity. Urethanes
    used today cure with the assistance of moisture in the air. So
    even if the room temperature is above 70 degrees F, it’s possible
    to have very low humidity, which will hinder proper curing times.
    For situations such as this, it may be necessary to use running
    water to increase the moisture content of the air.

    Proper Bonding

    Even after proper surface preparation, the adhesive still must
    have a large enough area to bond to the glass properly. The minimum
    bonding area is at least 1/2 inch on the bottom side of the glass
    (Figure 1-2). The strength of the bonding is obtained from this
    1/2-inch surface, not from the edges of the glass.

    Sometimes, a damming strip or tape is used as a backstop for the
    urethane adhesive. This damming strip is placed down on the edge
    of the pinchweld. Note: Using these damming strips may not be
    possible on very narrow pinchweld areas. Even if the automobile
    and adhesive manufacturer allow the use of a damming strip, it
    must not take from the 1/2-inch area for the adhesive (Figure


    It’s also important to understand that these damming tapes or
    strips don’t provide sufficient bonding for an immediate "drive
    away." They assist in holding the glass in place during curing,
    but this doesn’t meet all safety standards.


    Having a method of documenting or receiving documentation from
    your vendor about these installation factors is also extremely
    important. The following information should always be documented
    when the installation takes place:

    1. Date and time of installation.
    2. Vehicle information (year, make, VIN number).
    3. Owner information (name, address, repair order).
    4. Installer information (name, company).
    5. Location of installation (where, inside or outside, temperature,
      relative humidity).
  • Part information (name, part number/NAGS number, clips and
    moldings replaced).

  • Adhesive (brand, part number, batch number, primer used).
  • Installation method (full or partial, dam type used).
  • Release (date and time).
  • Additional notes.

    Without this documentation, you have no proof of the method or
    products used if there’s ever a question regarding proper installation.
    Many pre-made forms are available to document this, but what’s
    important is that you do it consistently. Whether you do the glass
    work internally or sublet it, you need documentation for every

    Managing the Business

    The collision repair portion of your business requires proper
    management to perform and be successful. And, if you elect to
    venture into the glass business, you need to have the management
    skills and knowledge for this industry too. There are national,
    state and local associations for the glass industry to help you
    do this, just as there are for the collision industry. I’ve had
    the opportunity to speak with these glass-specific groups in the
    past, and they offer a valuable service to their membership.

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    The key here is to not take for granted the skills and investment
    required to perform this service. And don’t forget the liability
    issues involved, which can be extreme; some of the awards given
    by the courts in the last several years have been in the millions
    of dollars.

    If you thought auto glass installation was easy and that anyone
    could do it, think again. The knowledge and skills required today
    for proper glass installation equal the knowledge and skills required
    to properly repair collision damage on today’s vehicles. And,
    as with collision repair, glass installation isn’t for everyone.
    The question is: Is it for you?


    Contributing editor Tony Passwater is a long-time industry
    educator and consultant who’s been a collision repair facility
    owner, vocational educator and I-CAR international instructor.
    He’s taught seminars across the United States, Korea and China
    and is currently an industry consultant. He can be contacted at
    (317) 290-0611 or [email protected]

    Training and Certification

    Proper training and certification are extremely critical today
    when it comes to proper glass installation. The days of just "short
    cutting it" and using a bead of urethane are gone!

    Major suppliers generally have their own internal training and
    certification program, but unless you’re able to hire someone
    from these organizations, they’re not generally available to outsiders.

    National training organizations dedicated to the auto glass industry
    are another option. Three national training organizations that
    come to mind are the Auto Glass Technical Institute (AGTI), based
    in Virginia; Performance Achievement Group (PAG), based in Wisconsin;
    and the Automotive Glass Consultants (AGC), also based in Wisconsin.
    These groups can supply a very in-depth training program for your

    For certification, the National Glass Association (NGA) offers
    a three-level certification program that requires written testing
    and work-experience requirements. This test is based on agreed-upon
    glass industry standards. The organization can be reached at (703)
    442-4890 or for further information.


    If you wish to become informed but still want to sublet your glass
    work, you can take the I-CAR Glass Replacement Course. This course
    is designed to provide all attendees with what to look for in
    a proper installation, preparation methods and adhesive variables
    – along with a live class demonstration of two main types of installations.

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