by Bob Beranek
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Last November I posted an article on the contents of a Vehicle Identification Number (VIN). I explained the digits used to identify an automobile and detailed what information the VIN did (and did not) contain. Recently however, I have heard people in the industry tell me that they have a VIN decoder that picks out the right windshield for a vehicle. In my experience, the decoders may not complete the assignment.

It’s true, knowing the complete VIN can shorten the list of windshield options you have to choose from, but it doesn’t necessarily pick the part for you. Let’s take the Jeep Cherokee as it has 51 windshield options. Last week I conducted a training course where we had to replace a 2015 Jeep Cherokee windshield. When we typed the VIN into the decoder on my software, it gave us over 20 windshields to choose from. 

On the same day, we had a Ford F150 that gave us the part we needed via a VIN decoder, so they aren’t useless. However having a decoder will not give you all of the information you need for all vehicles. You may have to contact the dealer.

How can a dealer know what glass is in the vehicle by the VIN and we can’t? It’s because they have access to what is called the “build sheet.” The build sheet is the actual information of what was included in the vehicle at the time of assembly. The VIN does not include the glass part number, but the build sheet does. With this proprietary information the dealer can tell you exactly what glass was put into the vehicle. But will they?

Some software companies have told me that they draw their information from build sheets, which is great. However most still admit they don’t have all of the information required for all makes and models. Some dealerships are happy to help, but it’s to the carmakers/dealers advantage to keep some things to themselves rather than releasing all of the information they have available. If all specifications and information were made public, the carmakers’ dealer base would be undercut and beaten at every turn.

The reality is professional questioning of the customer is still important in having the right windshield for the job. A significant skill of any customer service representative (CSR), technician or owner is the ability to lead the customer through a series of questions that will pare down the information necessary to pick the correct part. If there’s something related to the glass that can’t be seen, heard or experienced by the customer, then the professional CSR can ask about other options that will lead them to features that would differentiate a glass part. For example, if a vehicle has a heated mirror, then it is likely that it would have a wiper park heater as well. 

I have an idea. What if we help our fellow auto glass professionals and send in hints on questions to ask the customer that narrows down the windshield options? Make sure the hints are correct before sharing them. Send them as a comment to this post, I know this would be greatly appreciated and a big help to everyone.  I’ll even bet that the more you give, the more you will receive in new information.       

Let me begin and end this post with one request. Invite your adhesive rep to visit and provide training for your technicians on what’s new with their products. Although I routinely preach the importance of cleaning glass properly to insure solid bonding, today that advice is more important than ever. There are several new procedures and products that should be introduced and put into practice as soon as possible.

Adhesive representatives and chemical engineers tell me that the number one reason for adhesive failure is improper cleaning of the surface. Adhesive companies have stepped up their training on this topic recently for good reason.

We all know that the most important area on the windshield for care in cleaning is the frit area. The frit is the black painted band around the interior perimeter of the glass that protects the urethane from ultraviolet (UV) light. It’s usually applied to the number four surface of the glass. The frit not only protects the urethane from UV light, but it also provides an additional mechanical bonding surface for the urethane to bite to. The peaks and valleys created by the frit paint application in the manufacturing process provides more bonding surface for better adhesion.

Until now, techs didn’t worry about internal frit preparation. What is an internal frit? It’s the black band of ceramic paint applied to the number 2 surface of the glass, not the number 4 surface. There is at least one manufacturer that applied a frit to both the 2 and 4 surfaces for aesthetic reasons. However, we are more concerned with the former type frit and not so much on the latter. We’ve seen internal frits for years, but until recently we didn’t know they needed special preparation.

Internal Frit

Traditional Frit


The preparation of the internal frit is very important to bonding success. Some use additional products to abrade/clean the surface. While others may use special procedures, such as “wet scrubbing” to clean and prep the surface for bonding. Either way, there have been changes you should be aware of and trained on accordingly.

For those of you that use primerless products, please make sure that the cleaning and prepping procedures are followed and practiced daily on every installation. Primerless products are very convenient because they eliminate a step in the replacement process which saves time and money. However, primerless adhesive installations allow no room for error when it comes to preparation of the glass surface. Any contaminants or “shortcuts” in preparation of the glass surface can result in poor adhesion, injury to your customers, and a liability for your shop.

As promised, I’m ending this post by encouraging you to invite your adhesive rep for a visit and ask them to train your techs on what’s new about their products. Adhesion standards do change and your installation procedures must change too. This is important stuff, guys. Do it.