Car windows with black band on the margin, reducing the actual size. Why?

General Discussion
41

I just had the windshield replaced in my '14 Subaru this morning so I have the answer. The glass is set in a bead of urethane caulk. Anyone who has ever done any caulking knows that a bead of caulk is never pretty and never uniform. All the fixed glass on a vehicle is installed this way. The black band hides the caulk seam, and some of the metal that would otherwise be visible.

So the short answer is cost, make the window over sized, put a black band around the edge and stick it in place. All that other trim that used to be used is no longer needed.

42

That explains 1" of the black band. The remaining 2"-5" (honest!) is for styling (bigger looking windows).

43

You guys should start Driving Italian:

Whatever is behind you does not matter. Only the traffic you are overtaking is important.

That was the excuse for the tiny windows in Laorghinis and the like.

44

Only 1/2" of overlap is needed for the urethane. This picture of an old Caravan shows the difference in size between the window opening and the size of the (missing) glass. There is no urethane in this application, this is a hinged glass. The window openings are designed with safety in mind and the exterior for appearance.

45

“That explains 1” of the black band. The remaining 2"-5" (honest!) is for styling (bigger looking windows)."

Actually it was about 4" at the bottom and about 3" on the sides and top, and it looks like it needed every bit of that. Otherwise additional trim would have been needed. The bottom of my windshield had a heater grid in it also.

46

As good as the Forester is, notice how much those black bands have grown, 2016 vs. 2007:

47

yup, all in the name of “style”.

48

Would there be a benefit in reducing the glass to the same size as the opening?

49

Excellent point, Nevada. The answer is “nope”.

Beyond that, the windows are now used in the design as a part of the crashworthiness of the vehicle. They transfer energy to other parts of the structure very well. Glass has excellent compressive strength and even very good tensile strength. It’s possible that if the bonding surfaces were smaller, they would become the “weak link in the chain” and fail to allow the glass to properly transfer the energy to the steel structures. In short, large bonding areas may be as much for structural integrity in the bonding system as for style.

I’m only theorizing here, but it’s something to consider.

50

If you make the glass smaller, then you have to add all that trim to cover up the ugly.

51

If I had seen this conversation earlier, I would have taken a picture of the Legacy with the glass out and you would clearly see what I am trying to say. The black edge is simply a cost saving thing, it lowers manufacturing costs.

52

“Trim”? What is “trim”? :lol:

The more I think about it, the more I begin to think the wide bonding area is structural in nature.

53

The actual bonding area is only about 3/4" wide, not nearly as wide as the black strip.

54

I checked my windshield - black strips are 1" wide on the vericals, that’s all the width needed for a strong bond. The rest (3" on the bottom, 2" on the top) is for looks or other needs.

55

Also, take a look at some windows and it is obvious the blacked out area is there to make the window look larger then it really is - that behind that blacked out are is structural framework. This may or may not result in a visibility issue, but it certainly changes the way it looks.

I had a 1993 Mustang where the 3/4 window was literally twice the size of the opening. The result was a much more pleasing roof line and better rollover protection, but is seemed an odd way to achieve that result.