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The forbidden topic that windshield manufacturers will not discuss or speak of is the "Weak Spot".

When we first came out with the Edgeguard and were offering use to windshield manufacturers one being PPG, an engineer of theirs called me to discuss it. When he stated the phrase 'Weak Spot" which was the first time I had heard it and he realized I did not know what it was he said, "I am not allowed to talk about it" and hung up. I knew from repairing edge cracks and surveying parking lots that there was something going on at the first couple of inches around the perimeter, but this was the first time I heard a name for it. A few weeks later at an NGA Glass Show where we had a booth displaying the Edgeguard a Ford VP came up to the booth and I stated, "How do like the way we cured the weak spot". He began to talk and then set up meetings with Ford engineers where we had many discussions about the "Weak Spot". We have since discussed it, including the product liability issues with Pilkington, PPG, Safelite, GM, Ford, Chrysler, State Farm, Honda and Toyota. What are they waiting for? Probably a Consumer Class Action, like with the brakes (Toyota), tires (Ford) and accelerator (Toyota). Honda did get a class action for the Element edge cracking from the bottom but it settled before trail.

A few years ago four consumers who had edge cracked windshields filed individual product liability small claims suits, one each against a windshield manufacturer and three vehicle manufacturers. Multiple attorneys in black suits from Detroit flew in and showed up at the court house in Colorado for the mandatory pre-trial mediation. I was a witness and they requested for the mediator to have me leave the mediation room because I was a witness and not a party. Their presence intimidated the plaintiffs into dropping the case. The windshield manufacturer just paid for a new windshield before mediation. My opinion of the flying in of multiple attorneys for a $350 small claim mediation only showed me they know the issue is of great concern for product liability.

Polaroscopic Photograph of the Weak Spot

weakspot-photo-1.jpg weak-spot-after-installation.jpg

Before installation and after installation

How does it happen? During the molding process the cut flat glass for whatever windshield is being made is placed on a metal mold and it goes into the oven. The glass softens and then sags into the mold. When it comes out of the oven temperatures clash at the edge area and the glass cools from the outer surface inward. The outer layers contract faster than the interior creating a pulling effect on the interior resulting in residual stress. This is the weakest area of the windshield. The weakest area of the windshield is also the area where it is glued to the vehicle, which increases the residual stress and adds it own installation stress. The residual stress causes this area to fracture 2 to 2.5 times easier than the rest of the windshield and the installation stress will cause the fracture to crack immediately (called the edge crack) to relieve the installation stress, which is usually at about 8-12 inches.

For more information go to SAE website under technical paper series report 1999-01-3160 Windshield Investigation - Manufacturing & Installation Stresses, cost is $10.00

OEM versus Aftermarket and the "Weak Spot"

The major difference in the costs to manufacturer the OEM versus the Aftermarket Auto Replacement Glass (ARG) is time and heat, time is money and so is heat. The OEM is annealed slower taking more time and using more BTUs. Under the contract with the vehicle manufacturer the specs and tolerance for an OEM must keep the "Weak Spot" around the perimeter edge under 1,000 psi with an average not over 750psi. Vehicle manufacturers do not want the windshield to edge crack before they get the windshield sold. There is no contract to keep the ARG Weak Spot (residual stress) down, so they are annealed faster using less time and BTUs and the residual stress can be much higher and sporadic around the entire perimeter. It can be 1,000 psi on a spot on the side and 1,500 at the lower corner. Some have more than others. One test we did that was published by SAE showed the FYG had the least and was the hardest to fracture both on the edge and the middle. The Safeguard factory windshield did not score very well and neither did the Pilkington ARG.

To read this report go the the SAE web site technical series #2002-02-1991 and download it for $10.00

One ARG manufacturer giving a tour of a committee of the manufacturing process stated that because of Edgeguard we are now the largest buyers of 3M post it pads. They placed a post-it on each of the four corners before it went into the oven which reduced the residual stress in the corners. Windshield manufacturers could coat the weak spot for about one dollar using the same silk screening machine that places the frit on the inner lite, but as two windshield manufacturers stated to me, "We don't want anything to do with anything that is going to stop windshields from cracking."


One way to beat the unfair competition/insurance network steering is to put a $7.00 investment into each one of your replacements by curing the defect and selling a better product.

When those customers are calling, educate them, you can have the advantage of stating the fact that your competition is selling a defective safety product and you are not. Safety devises with a manufacturing defect that have a "Feasible Alternative" must either be cured or have a warning notifying the consumer of the cure. The product liability doctrines are called "Feasible Alternative", "Duty To Warn" and "Failure to Warn". Failure to Warn is Strict Liability. Your biggest competitor is doing none of this and is on notice.

The spray-on coating replaced our film coating three years ago. It is clear, virtually invisible and has a perfect track record thus far. Meaning no windshield with the coating has edge cracked. Now do not worry about repeat business, customer loyalty with this product is extremely high. Put yourself in their shoes, would you not appreciate a business that discloses the facts and your options, tells the truth and does not try to mislead you. Consumers with an Edgeguard windshield bring in their stone breaks (in the middle of the windshield) the day they get them. They also refer you to their friends and family They will remember you and they will trust you and trust is steer-proof.

How is it applied - The defect is about 1.5 - 2 inches wide around the perimeter. Surveys have shown that 77% of edge cracks have an impact point in the frit area, so we just coat the frit area.

  • Step One - place the windshield on a rack and mask off the frit area.
  • Step Two - prime with Xtra Bond and let it dry for few minutes.
  • Step Three - Spray on a light coating and let it dry for five minutes.
  • Step Four - Spray on a medium coating and let dry for five minutes, then repeat step four until you reach your desired coating, which is usually two to three coats or 2 to 3 mills.

The Phantom Warranty

One of the items of the insurance/network steering script that pops up on the CSRs computer screen when they ask for the phone number of the shop and you are an independent non-participant like I am is the Insurance Company’s National Warranty Steering Script.

There are four insurance/network steering items/statements in their script: (1) the negative innuendo of not being an Insurance Company Approved shop; (2) the false cannot repair over six-inches (3) the misleading you might pay more if you go to  that shop and; (4) the you won’t receive the Insurance Company’s National  Warranty.

The warranty is non- existent on a repair and repairs are 30-40% of the claims. Here are two transcriptions of recorded phone calls. First they lie about what is repairable but the consumer knows better, then notice how getting the CSR to admit there is no warranty is like pulling teeth and they continue to try to steer it using a non-existent warranty after the insured requested my shop and also continues to try to steer it into a replacement after the insured has requested a repair. I have removed the names to protect the guilty (for the time being) and the innocent.


Insured: I
Network/Insurance Company: C

C: Thank you for calling______________. How may I help you?
I: Hi, I need to see about getting some glass repair done.
C: Ok, ma’am. May I have your first and last name?
I: ___________________
C: And are you the policyholder?
I: Yes.
C: Ok, and is it just the glass or is there any other damage?
I: Just glass.
C: And what State was the policy written in?
I: Colorado.
C: Were there any injuries at the time when the glass was damaged?
I: No.
C: And when did this happen?
I: Saturday, the 12th, this month.
C: Ok, and how did it happen?
I: I was driving on the interstate and a truck went by and some rocks flew up and hit my windshield.
C: Ok.______________, may I have your daytime telephone number starting with the area code?
I: __________________
C: ___________insurance company has confirmed coverage on the ____ . Now, can you describe the location and size of the damage on your windshield?
I: There’s two chips and one eight-inch crack just about at the windshield wiper.
C: Ok, so __________ recommends that we replace that.
I: I want to get it repaired instead.
C: Um, we wouldn’t be able to repair an eight-inch crack.
I: Why not?
C: Um, anything longer than six inches is really un-repairable. It won’t take.
I: What will happen if they repair it instead of replace it?
C: Well, you can ask the glass shop. I don’t think the repair would take, but you can discuss it with the glass shop if you like.
I: Ok.
C: Are any of the chips in the direct line of vision?
I: No.
C: Ok, do you want me to put it in as a repair? (NOTE: After making a false statement about repair the CSR attempts to steer a repair into a replacement and it is also after the insured has requested a repair.)
I: Yes.
C: Ok, since it’s a repair, your deductible of $100.00 has been waived.
I: Right.
C: And, since your windshield qualifies as a repair, _____________ has Repair Specialty Shops in your area who provide professional services. With your permission, I can schedule an appointment now with one of them. Will that be ok?
I: No, I want to use Ultra Bond.
C: Ultra Bond, have you used them before?
I: Yes.
C: Are they in your zip code area?
I: They’re in my city area. I mean, it’s within the same city.
C: Do you know what the zip code is?
I: ______.
C: Ok.
I: Same city as mine.
C: Alright. And what was the name of the shop again? I’m sorry.
I: Ultra Bond.
C: Ultra Bond, ok. In Grand Junction ?
I: Correct.
C: I’d be happy to contact the company you’ve selected, but would like to inform you the service provider you have chosen is not a _____________ program participant. Although you are free to choose any services provider, I must inform you that in choosing a non-participant, your replacement or repair will not be covered under the National Warranty offered by ___________ program participants. Any warranty to coverage will be to the terms offered by the company you have selected. I cannot confirm the warranty terms offered by a non-participant. Did you want to continue with Ultra Bond? (NOTE: Continued steering attempt after the insured has already requested my shop using a warranty that does not exist)
I: Yes. Can you tell me what the _____________ warranty is on a repair if I were to use a different company?
C: Uh huh, let me just look it up so I can give you the exact information.
C: Windshield repairs are warranted against spreading for the life of the vehicle or the length of the warranty, whichever is shorter. The warranty is limited to the credits towards the purchase of a new windshield installed in the original vehicle. And the applicable deductible for the new windshield is the responsibility of the owner.
I: So, it’s basically the same thing. It doesn’t matter. I still have to replace it. I still have to pay that deductible. So there really is no warranty.
C: Well, it’s just that the warranty by ____________would be under the warranty of the shop.
I: But, there’s no warranty by ____________ because it’s the same deductible for me.
C: The warranty is limited to a credit towards the purchase of a windshield.
I: But my deductible is the same regardless. Ok, that’s fine. I get it.
C: Ok, did you want me to continue with Ultra Bond? (NOTE: 2nd attempt to steer using the National Warranty after the insured has requested my shop and they know the deductible is higher than the repair)
I: Yes, I do.


Insured: ___________
Ultra Bond:  Rich   ( R )
Network:  ___________

(NOTE: I made the phone call and told the CSR I am the shop and  the insured is sitting here in my shop and you are on a speaker phone)

N:  Okay sir I’d be happy to contact the company you have selected but would like to inform you that the service provider you have chosen is not a/an  _____________Program Participant.  Although you are free to choose any service provider, I must inform you that choosing a non-participant the replacement or repair would not be covered under the National Warranty offered by ____________ program participants.  Any warranty coverage will be to the terms offered by the company you have selected.  I cannot comment on the warranty terms offered by a non-participant.  May I contact the company you have selected or would you prefer to hear a selection of ___________ program participants in your area? (NOTE:  Steering attempt using a non-existent warranty)
I:  (to Rich)  Well, what do I tell them?
R:  They are trying to steer you, just say you want to use me.
I:  Okay.
I:  Yeah, I just want to use this one here.
N:  And all I basically  stated was that whatever warranty it’d be covered under, it would be under that shop’s warranty and not the __________ National Warranty.
I:  Okay.
N:  And when would they be doing that work sir?
R:  Right now.
I:  Okay sir.  That’s one windshield repair at ________ flat rate.  Do you accept pricing?
R:  Yep.
I:  Thank you sir, and may I have your first and last name?
R:  Rich
I:  Thank you sir and your last name?
R:  Campfield. 
I:  Okay, sir one moment and I will have that dispatch number for you.
R:  Okay.
I: The dispatch number is going to be # _____________  Is there anything else I can help either of you with today?
R:  Yeah, under the National Warranty for a repair...he has a thousand dollar deductible, so let’s say six months from now this thing cracks or he wasn’t happy with it, under the ____________ Warranty, what does he get?
I:  Okay sir, any time there is a failed repair, what happens is like if he went with a participating shop?
R:  Yeah.
I:  We would contact that shop and let them know it was a failed repair and his deductible does apply.
R:  So he gets nothing.
I:  Well we can call that shop and see if they are willing to try to fix that repair.
R:  But if he is not happy with it under this warranty: he doesn’t get the $50 back and; he gets no free windshield and; he gets no reduction off of his deductible.  He pays the full price of his deductible.
I:  He still is required to pay that deductible any time the windshield is replaced, yes sir.
R:  Right so there is nothing for him in this National Warranty then?
I:  For repairs, usually, not really sir, but for replacements, that’s a little bit different.
R:  Yes it is.  It is different, so that’s why you shouldn’t be saying that about repairs.
I:  That is still…I mean it just pops up and we’re required to say that sir.
R:  I understand totally . . . that warranty does not apply to a repair.  They get no warranty.
R:  What was your name?
I:  _________________
I:  Thank you sir. 
R:  Bye.

Our next newsletter will be the recordings of what happens when the consumer calls in for a repair warranty.

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   Before/After Photos
   Incorrect Resin Photos
   Correct Resin Photos
   Fundamentals of Windshield Repair Adhesives
   Repairable Windshield Damage
   Windshields are Made to Crack
   Windshields Repair Standard (ROLAGS)

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