MTFCA Forum

Sorry if this is a basic question but how can I tell if I have pate glass or safety glass for my windshield?

Thanks
Ron

Look at reflections of one of your fingers in the glass very closely. If there is one reflection it is plate glass. If there are 2 reflections it is safety glass. Or just take a hammer to it and then it will be easy to tell.

Rap it with the edge of a loosely-held quarter.

A dull sound indicates laminated safety glass. A sharp sound indicates plate or tempered glass.

Not sure about the sounds? Try it on your modern car: windshield is laminated, other glass is tempered (sounds like regular plate glass).

There's the original plate glass which breaks into large, dangerous shards. Then there's tempered safety glass which breaks into gazillions of tiny pieces which cause little harm unless you get a bit in your eye. Then there's laminated glass which is two or more layers of glass sandwiching a clear membrane. This membrane stops the glass from shattering into little pieces or large shards.

In Australia professional glass works are obliged to etch brand any glass used in auto windows. We just look for the marks. However, model T glass is always flat. It can be cut by anybody to fit, and may not be branded. If you can access a raw edge, you can see if it is laminated glass. Tempered safety glass will have a couple of tiny dimples where the glass is held during the tempering process. However, these are at the edge of the pane, and could well be hidden in the frame.

Hope this helps.
Allan from down under.

Hold a flame up to such as a match or lighter. If you see two flames in the glass it’s safely.

Look at the edge. You should be able to see if it has 3 layers or not. Glass, plastic, glass.

Mark beat me to it. If your windshield has one edge which is open and not covered by steel, you can see the two layers. If it has two layers it is safety glass. If only one layer, it is plate glass.
Norm

You're correct in wanting to find out.

My great-grandfather was killed in a minor accident in his Model A (the car could've been driven away from the scene), near Baytown, TX.

The plate glass shattered and severed an artery in his neck. He bled out sitting in the seat.

If you look at the glass edgewise you can see the thin lamiinate sheet between it. Original T plate glass will be whiter and clearer than the laminated glass. It has a very slight greenish tint to it caused by the laminate in between .

There is an old myth that seeing two reflections in the glass means that it is safety glass. I have tested and proven this myth to be false. Every pane of glass has two reflective surfaces. There is one on the side you are looking at and one on the opposite side. Hold a flame, candle, etc. up to the glass. The near surface will have a reflection of the flame. The opposite side will also reflect light and will show a second reflection. In a recent post on this subject a forum member included a photo showing two reflections and proclaimed that it was safety glass. That photo was borrowed from one originally posted years ago by Dan Treace where he stated that the glass in the photo was a single pane. Dan's photo agreed with my test. Don't assume, incorrectly, that you are safe if you see two reflections.

Rustyford makes a good point about antique car history. We will never know how many antique car accidents had deaths or mutilation’s from being in cars that didn’t have safety glass.
Yes some people probably were able to get out before accidents happened but not all.

This thread is a good reminder of the importance of modern safety glass.

If it has not been cut off in cutting the glass to size, there should be a stamp or mark in the corner signifying that it is safety glass. I believe the stamp or mark is required by law, but glass places cut from a big piece of glass plate that has one mark in the corner and after cutting, do not re-mark the pieces they cut off. This mark can be seen in the corner of modern windshields. Jim Patrick

A good photo that show differences:

I agree with Chris, the tap test is a good way to tell the difference. Laminated glass has a more dull thud and plate glass has a more sharp rap.