Dear Glass Detective,
What are the tiny specks I see in tinted glass? I see them in my car glass and I see them in my home’s windows. When the sun hits my car’s windshield at about 10 o’clock in the morning you can really see them.
No one has had an answer yet. The dealership had to put a new convertible top on my car and it still has specks in the glass. My other vehicle has specks in it too. It seems like they are between the layers of glass; you can not feel them.
Let me begin by thanking you for contacting the Glass.com® Glass Detective with your questions regarding specks that you see in both your windshield and residential window. In fact, you stated that you see specks in both of your car windshields. While your question is one we have heard before, it is still rare.
Most of us look “through” glass to see something on the other side. Therefore, we rarely notice small imperfections within the glass itself. This is particularly true with windows in homes and businesses. Typically, we are so focused on something on the other side of a window that we don’t notice the glass itself. Nonetheless, there are often tiny imperfections in glass panes. The discerning eye, which you apparently have, can sometimes see these imperfections when inspecting the glass closely.
You stated in your e-mail to us that you noticed specks in the windshield in your convertible and apparently, upon further investigation found them in your SUV windshield as well. I don’t necessarily believe that your eyes are playing tricks on you. You are seeing specks (imperfections) in the glass. For the most part, this is acceptable.
Windshields are made by laminating two pieces of glass. A PVB interlayer is used between the two pieces of glass to “glue” them together. These typically are made in what is known as a “clean room.” For quality purposes, a speck of dirt or dust on either the glass or PVB will forever be captured when the windshield is made.
As for your window glass, any particle of debris in the glass flow as it comes out of the furnace is in the glass forever after it cools/solidifies. Most window panes are also coated with a low-emissivity (Low-E) coating. This is applied to the glass surface at the manufacturer’s facility. The machines that produce this glass are not perfect for indefinite periods. The people who operate them and handle the glass components are not perfect either. Things happen all the time.
Now, you are probably getting ready to ask, “Why hasn’t someone done something about this problem?” Don’t ask. They have. Not only have several volunteer organizations, but also the federal government itself has all kinds of standards and regulations of glass in general, and imperfections in particular. There are even standards that regulate how you are to look at (through) a piece of glass to determine whether or not it meets any or all of the applicable standards. Seeds, bubbles, stones, dirt, scratches, etc. are all addressed.
Some people think the glass standards are too loose. I am not one of them. A lot goes into the manufacturing of glass. Things do not always go as perfectly as everyone would like. I think the manufacturers do a great job with their quality control efforts. Fabricators that make the glass end products that we see and use every day are extremely good. As an aside, answering your questions did bring to mind an insulating glass unit I once saw several years ago it had two dead flies forever enclosed in the air space between the two pieces of glass. The crew assigned to install it noticed the two intruders when they went to take the glass off the truck to install it in a customer’s home. Fortunately, it was never installed, but it was kept around the shop for a few weeks as a curiosity piece.
Let’s wrap this up. You are not going crazy thinking you see specks and spots in your glass. You likely have excellent eyesight, and you see the most likely acceptable imperfections in the glass you have. Just as we as humans are not perfect, neither are the things we humans make. I really hope this response to your question helps in some way and thank you again for making contact with the Glass.com® Glass Detective.