by Bob Beranek
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My son Jay recently reported a problem with laminated door glasses breaking after installation. He said he noticed that the aftermarket parts were breaking at the mounting brackets, and that the glass itself seemed to be slightly out of bend. I hadn’t heard about this before, so I did some research with other technicians and found that this was a common problem.

The reason this intrigued me is that laminated door glasses are supposed to be constructed with two layers of heat-strengthened glass and lamination. Though “heat-strengthened” glass is not true tempered glass as defined by ANSI Z26.1, it is supposed to be heat-strengthened enough to withstand the abuse put upon it by the operation of the movable door frame and glass.

This raises a few questions. Did the aftermarket manufacturers reverse engineer the laminated-door glasses correctly? Did they recognize that the glass used for door-glass construction should be heat-strengthened and not just annealed glass? If they were aware of the necessity for the heat-strengthened glass construction, did they replicate the process and use the OE specifications or weaken it for a price point?

Here is the issue as I see it. The actual purpose for making door glasses laminated, rather than tempered, is murky. Was the change made for acoustical reasons to benefit the comfort of the occupants and the performance of voice-activated systems? Or are laminated parts safety devices that act as a backstop for the side impact airbags/curtains?

Depending on who you talk to at any given time, the answer changes. It is to the benefit of carmakers to consider glass as a performance feature, rather than a safety feature, to keep free of Federal regulation.  However, if you are a car salesperson, safety sells and, if a safety reason can be attached to the feature, it may close the sale.

Now let’s look into the minds of the ARG manufacturers. If the glass you produce is a performance feature, not driven by safety, and the cost of producing a part is prohibitive to the goal of reaching a price point, then why not laminate for acoustics but weaken the strength of the glass portion to meet that price objective? It makes perfect business sense.

Heat-strengthening glass is an expensive process. You must take the process steps of strengthening the glass (like tempering) but then add the additional step of lamination. Increasing the cost of a finished product that is naturally slower selling, like a door glass, may not make financial sense. Why not eliminate one of the processes that, in some assessments, are not necessary to the safety of the vehicle to meet the price point their customers demand?

In my opinion, the heat-strengthened auto glass parts serve both performance and safety purposes. If safety is even a small reason for its existence, it is my opinion that the product used in our service of auto glass repair and replacement must meet the specifications of the OE part. So, buyer beware. When buying ARG laminated side parts, think of the primary purpose of the part and act accordingly. I prefer to err on the side of caution.

One of the benefits of being a trainer is having the opportunity to observe and learn tips for using and operating both new and existing tools. I thought I would share some things that I have learned while teaching Auto Glass University.

  1. When the glass part is original equipment, and there are no factory installed gravity stops, assume there are guide pins inserted into the upper pinchweld. These will have to be separated from the interior glass surface to facilitate wire progression.
  2. Do you want an easy way to find the guide pins? Use the rearview mirror you just removed to see where the pins are located.  Then separate with a stiff sharpened putty knife or paddle blade.
  3. Try not to cut the cord for reuse. Every time the cord is cut, it is restricted to the size of the glass part it will fit.
    • Start the cord, and insert it around the glass edge. Do not cut it.
    • Make a loop with the cord, and insert it through the islet on the anchor cup bottom to top. Repeat using the same loop. Then insert the islet through the loop and pull.



    • This knot is very strong and will not give but will allow the knot to be released without cutting the cord. Thanks to Gilbert Gutierrez for the knot idea.
    • Mount the anchor cup to the outside glass surface leaving the cord reel hanging from the anchor cup. Cord will not chip the glass and cause premature fracture.
    • Once most of the glass is cut out, release the anchor cup. Lift the glass where it is separated from the bead and push the anchor and reel inside. Then remount on the inside surface and finish the cut out.
    • Once the glass is removed, the cord loop is released from the islet, and the cord knot is released allowing it to be reused without cutting it.
  1. Sometimes the only available way of mounting the operating cup prohibits the use of pads to protect the dash and inside moldings. If you are using cord rather than wire, you can use a plastic stick or even a gloved hand or finger to push the cord to the inside glass surface to protect the moldings and headliner. I would not suggest using your finger if wire is being used.  The wire can cut through your gloved hand.
  2. Are you having trouble threading your cord through the hole in the wire starter? Try using a needle threader you can find in a sewing supply store or department store. They are inexpensive and work well if you get one that is more substantial than the little aluminum one.













6. The closer the wire or cord is to the glass, the better it cuts, and the safer the interior moldings are from being damaged. Push the protective pads and, thus, the wire/cord as close to the inside surface as possible.

7. Believe me, you DO NOT want to cut the VIN plate off. Make doubly sure that the wire/cord will clear the VIN plate when you get close to it. Take it slow and easy.

8. Speaking of slow and easy, when you cut the corners, take is slow around the radius. Pull and relax, pull and relax. This is where the wire/cord is stressed the most and where it will break most often. When the cuts are going easy, you can go as fast as you want. When it is tensing up, take it slower.

9. Threading the wire/cord is as simple as tucking the wire/cord under each corner and under each gravity stop. The straight away will take care of itself. You may want to make sure that if the cutting medium is wire, it doesn’t make contact with the roof paint. You may have to use tape to hold it under the glass edge at the top.